pdcp.c

/*******************************************************************************
    OpenAirInterface
    Copyright(c) 1999 - 2014 Eurecom

    OpenAirInterface is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.


    OpenAirInterface is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with OpenAirInterface.The full GNU General Public License is
   included in this distribution in the file called "COPYING". If not,
   see <http://www.gnu.org/licenses/>.

  Contact Information
  OpenAirInterface Admin: openair_admin@eurecom.fr
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  Address      : Eurecom, Campus SophiaTech, 450 Route des Chappes, CS 50193 - 06904 Biot Sophia Antipolis cedex, FRANCE

 *******************************************************************************/

/*! \file pdcp.c
 * \brief pdcp interface with RLC
 * \author  Lionel GAUTHIER and Navid Nikaein
 * \date 2009-2012
 * \version 1.0
 */

#define PDCP_C
#ifndef USER_MODE
#include <rtai_fifos.h>
#endif
#include "assertions.h"
#include "hashtable.h"
#include "pdcp.h"
#include "pdcp_util.h"
#include "pdcp_sequence_manager.h"
#include "LAYER2/RLC/rlc.h"
#include "LAYER2/MAC/extern.h"
#include "RRC/L2_INTERFACE/openair_rrc_L2_interface.h"
#include "pdcp_primitives.h"
#include "OCG.h"
#include "OCG_extern.h"
#include "otg_rx.h"
#include "UTIL/LOG/log.h"
#include <inttypes.h>
#include "platform_constants.h"
#include "UTIL/LOG/vcd_signal_dumper.h"

#if defined(ENABLE_SECURITY)
# include "UTIL/OSA/osa_defs.h"
#endif

#if defined(ENABLE_ITTI)
# include "intertask_interface.h"
#endif

#if defined(LINK_ENB_PDCP_TO_GTPV1U)
#  include "gtpv1u_eNB_task.h"
#  include "gtpv1u.h"
#endif

#ifndef OAI_EMU
extern int otg_enabled;
#endif


//-----------------------------------------------------------------------------
/*
 * If PDCP_UNIT_TEST is set here then data flow between PDCP and RLC is broken
 * and PDCP has no longer anything to do with RLC. In this case, after it's handed
 * an SDU it appends PDCP header and returns (by filling in incoming pointer parameters)
 * this mem_block_t to be dissected for testing purposes. For further details see test
 * code at targets/TEST/PDCP/test_pdcp.c:test_pdcp_data_req()
 */
boolean_t pdcp_data_req(
  const protocol_ctxt_t* const  ctxt_pP,
  const srb_flag_t     srb_flagP,
  const rb_id_t        rb_idP,
  const mui_t          muiP,
  const confirm_t      confirmP,
  const sdu_size_t     sdu_buffer_sizeP,
  unsigned char *const sdu_buffer_pP,
  const pdcp_transmission_mode_t modeP
)
//-----------------------------------------------------------------------------
{

  pdcp_t            *pdcp_p          = NULL;
  uint8_t            i               = 0;
  uint8_t            pdcp_header_len = 0;
  uint8_t            pdcp_tailer_len = 0;
  uint16_t           pdcp_pdu_size   = 0;
  uint16_t           current_sn      = 0;
  mem_block_t       *pdcp_pdu_p      = NULL;
  rlc_op_status_t    rlc_status;
  boolean_t          ret             = TRUE;


  hash_key_t         key             = HASHTABLE_NOT_A_KEY_VALUE;
  hashtable_rc_t     h_rc;
  VCD_SIGNAL_DUMPER_DUMP_FUNCTION_BY_NAME(VCD_SIGNAL_DUMPER_FUNCTIONS_PDCP_DATA_REQ,VCD_FUNCTION_IN);
  CHECK_CTXT_ARGS(ctxt_pP);

  if (modeP == PDCP_TRANSMISSION_MODE_TRANSPARENT) {
    AssertError (rb_idP < NB_RB_MBMS_MAX, return FALSE, "RB id is too high (%u/%d) %u %u!\n", rb_idP, NB_RB_MBMS_MAX, ctxt_pP->module_id, ctxt_pP->rnti);
  } else {
    if (srb_flagP) {
      AssertError (rb_idP < 2, return FALSE, "RB id is too high (%u/%d) %u %u!\n", rb_idP, 2, ctxt_pP->module_id, ctxt_pP->rnti);
    } else {
      AssertError (rb_idP < maxDRB, return FALSE, "RB id is too high (%u/%d) %u %u!\n", rb_idP, maxDRB, ctxt_pP->module_id, ctxt_pP->rnti);
    }
  }

  key = PDCP_COLL_KEY_VALUE(ctxt_pP->module_id, ctxt_pP->rnti, ctxt_pP->enb_flag, rb_idP, srb_flagP);
  h_rc = hashtable_get(pdcp_coll_p, key, (void**)&pdcp_p);

  if (h_rc != HASH_TABLE_OK) {
    if (modeP != PDCP_TRANSMISSION_MODE_TRANSPARENT) {
      LOG_W(PDCP, PROTOCOL_CTXT_FMT" Instance is not configured for rb_id %d Ignoring SDU...\n",
            PROTOCOL_CTXT_ARGS(ctxt_pP),
            rb_idP);
    return FALSE;
  }
  }

  if (sdu_buffer_sizeP == 0) {
    LOG_W(PDCP, "Handed SDU is of size 0! Ignoring...\n");
    return FALSE;
  }

  /*
   * XXX MAX_IP_PACKET_SIZE is 4096, shouldn't this be MAX SDU size, which is 8188 bytes?
   */

  if (sdu_buffer_sizeP > MAX_IP_PACKET_SIZE) {
    LOG_E(PDCP, "Requested SDU size (%d) is bigger than that can be handled by PDCP (%u)!\n",
          sdu_buffer_sizeP, MAX_IP_PACKET_SIZE);
    // XXX What does following call do?
    mac_xface->macphy_exit("PDCP sdu buffer size > MAX_IP_PACKET_SIZE");
  }

  if (ctxt_pP->enb_flag == ENB_FLAG_NO) {
    start_meas(&eNB_pdcp_stats[ctxt_pP->module_id].data_req);
  } else {
    start_meas(&UE_pdcp_stats[ctxt_pP->module_id].data_req);
  }


  // PDCP transparent mode for MBMS traffic

  if (modeP == PDCP_TRANSMISSION_MODE_TRANSPARENT) {
    LOG_D(PDCP, " [TM] Asking for a new mem_block of size %d\n",sdu_buffer_sizeP);
    pdcp_pdu_p = get_free_mem_block(sdu_buffer_sizeP);

    if (pdcp_pdu_p != NULL) {
      memcpy(&pdcp_pdu_p->data[0], sdu_buffer_pP, sdu_buffer_sizeP);
#if defined(DEBUG_PDCP_PAYLOAD)
      rlc_util_print_hex_octets(PDCP,
                                (unsigned char*)&pdcp_pdu_p->data[0],
                                sdu_buffer_sizeP);
#endif
      rlc_status = rlc_data_req(ctxt_pP, srb_flagP, MBMS_FLAG_YES, rb_idP, muiP, confirmP, sdu_buffer_sizeP, pdcp_pdu_p);
    } else {
      rlc_status = RLC_OP_STATUS_OUT_OF_RESSOURCES;
      LOG_W(PDCP,PROTOCOL_CTXT_FMT" PDCP_DATA_REQ SDU DROPPED, OUT OF MEMORY \n",
            PROTOCOL_CTXT_ARGS(ctxt_pP));
#if defined(STOP_ON_IP_TRAFFIC_OVERLOAD)
      AssertFatal(0, PROTOCOL_CTXT_FMT"[RB %u] PDCP_DATA_REQ SDU DROPPED, OUT OF MEMORY \n",
                  PROTOCOL_CTXT_ARGS(ctxt_pP),
                  rb_idP);
#endif
    }
  } else {
    // calculate the pdcp header and trailer size
    if (srb_flagP) {
      pdcp_header_len = PDCP_CONTROL_PLANE_DATA_PDU_SN_SIZE;
      pdcp_tailer_len = PDCP_CONTROL_PLANE_DATA_PDU_MAC_I_SIZE;
    } else {
      pdcp_header_len = PDCP_USER_PLANE_DATA_PDU_LONG_SN_HEADER_SIZE;
      pdcp_tailer_len = 0;
    }

    pdcp_pdu_size = sdu_buffer_sizeP + pdcp_header_len + pdcp_tailer_len;

    LOG_D(PDCP, PROTOCOL_PDCP_CTXT_FMT"Data request notification  pdu size %d (header%d, trailer%d)\n",
          PROTOCOL_PDCP_CTXT_ARGS(ctxt_pP,pdcp_p),
          pdcp_pdu_size,
          pdcp_header_len,
          pdcp_tailer_len);

    /*
     * Allocate a new block for the new PDU (i.e. PDU header and SDU payload)
     */
    pdcp_pdu_p = get_free_mem_block(pdcp_pdu_size);

    if (pdcp_pdu_p != NULL) {
      /*
       * Create a Data PDU with header and append data
       *
       * Place User Plane PDCP Data PDU header first
       */

      if (srb_flagP) { // this Control plane PDCP Data PDU
        pdcp_control_plane_data_pdu_header pdu_header;
        pdu_header.sn = pdcp_get_next_tx_seq_number(pdcp_p);
        current_sn = pdu_header.sn;
        memset(&pdu_header.mac_i[0],0,PDCP_CONTROL_PLANE_DATA_PDU_MAC_I_SIZE);
        memset(&pdcp_pdu_p->data[sdu_buffer_sizeP + pdcp_header_len],0,PDCP_CONTROL_PLANE_DATA_PDU_MAC_I_SIZE);

        if (pdcp_serialize_control_plane_data_pdu_with_SRB_sn_buffer((unsigned char*)pdcp_pdu_p->data, &pdu_header) == FALSE) {
          LOG_E(PDCP, PROTOCOL_PDCP_CTXT_FMT" Cannot fill PDU buffer with relevant header fields!\n",
                PROTOCOL_PDCP_CTXT_ARGS(ctxt_pP,pdcp_p));

          if (ctxt_pP->enb_flag == ENB_FLAG_NO) {
            stop_meas(&eNB_pdcp_stats[ctxt_pP->module_id].data_req);
          } else {
            stop_meas(&UE_pdcp_stats[ctxt_pP->module_id].data_req);
          }

          VCD_SIGNAL_DUMPER_DUMP_FUNCTION_BY_NAME(VCD_SIGNAL_DUMPER_FUNCTIONS_PDCP_DATA_REQ,VCD_FUNCTION_OUT);
          return FALSE;
        }
      } else {
        pdcp_user_plane_data_pdu_header_with_long_sn pdu_header;
        pdu_header.dc = (modeP == PDCP_TRANSMISSION_MODE_DATA) ? PDCP_DATA_PDU_BIT_SET :  PDCP_CONTROL_PDU_BIT_SET;
        pdu_header.sn = pdcp_get_next_tx_seq_number(pdcp_p);
        current_sn = pdu_header.sn ;

        if (pdcp_serialize_user_plane_data_pdu_with_long_sn_buffer((unsigned char*)pdcp_pdu_p->data, &pdu_header) == FALSE) {
          LOG_E(PDCP, PROTOCOL_PDCP_CTXT_FMT" Cannot fill PDU buffer with relevant header fields!\n",
                PROTOCOL_PDCP_CTXT_ARGS(ctxt_pP,pdcp_p));

          if (ctxt_pP->enb_flag == ENB_FLAG_NO) {
            stop_meas(&eNB_pdcp_stats[ctxt_pP->module_id].data_req);
          } else {
            stop_meas(&UE_pdcp_stats[ctxt_pP->module_id].data_req);
          }

          VCD_SIGNAL_DUMPER_DUMP_FUNCTION_BY_NAME(VCD_SIGNAL_DUMPER_FUNCTIONS_PDCP_DATA_REQ,VCD_FUNCTION_OUT);
          return FALSE;
        }
      }

      /*
       * Validate incoming sequence number, there might be a problem with PDCP initialization
       */
      if (current_sn > pdcp_calculate_max_seq_num_for_given_size(pdcp_p->seq_num_size)) {
        LOG_E(PDCP, PROTOCOL_PDCP_CTXT_FMT" Generated sequence number (%lu) is greater than a sequence number could ever be!\n"\
              "There must be a problem with PDCP initialization, ignoring this PDU...\n",
              PROTOCOL_PDCP_CTXT_ARGS(ctxt_pP,pdcp_p),
              current_sn);

        free_mem_block(pdcp_pdu_p);

        if (ctxt_pP->enb_flag == ENB_FLAG_NO) {
          stop_meas(&eNB_pdcp_stats[ctxt_pP->module_id].data_req);
        } else {
          stop_meas(&UE_pdcp_stats[ctxt_pP->module_id].data_req);
        }

        VCD_SIGNAL_DUMPER_DUMP_FUNCTION_BY_NAME(VCD_SIGNAL_DUMPER_FUNCTIONS_PDCP_DATA_REQ,VCD_FUNCTION_OUT);
        return FALSE;
      }

      LOG_D(PDCP, "Sequence number %d is assigned to current PDU\n", current_sn);

      /* Then append data... */
      memcpy(&pdcp_pdu_p->data[pdcp_header_len], sdu_buffer_pP, sdu_buffer_sizeP);

      //For control plane data that are not integrity protected,
      // the MAC-I field is still present and should be padded with padding bits set to 0.
      // NOTE: user-plane data are never integrity protected
      for (i=0; i<pdcp_tailer_len; i++) {
        pdcp_pdu_p->data[pdcp_header_len + sdu_buffer_sizeP + i] = 0x00;// pdu_header.mac_i[i];
      }

#if defined(ENABLE_SECURITY)

      if ((pdcp_p->security_activated != 0) &&
          (((pdcp_p->cipheringAlgorithm) != 0) ||
           ((pdcp_p->integrityProtAlgorithm) != 0))) {

        if (ctxt_pP->enb_flag == ENB_FLAG_NO) {
          start_meas(&eNB_pdcp_stats[ctxt_pP->module_id].apply_security);
        } else {
          start_meas(&UE_pdcp_stats[ctxt_pP->module_id].apply_security);
        }

        pdcp_apply_security(ctxt_pP,
                            pdcp_p,
                            srb_flagP,
                            rb_idP % maxDRB,
                            pdcp_header_len,
                            current_sn,
                            pdcp_pdu_p->data,
                            sdu_buffer_sizeP);

        if (ctxt_pP->enb_flag == ENB_FLAG_NO) {
          stop_meas(&eNB_pdcp_stats[ctxt_pP->module_id].apply_security);
        } else {
          stop_meas(&UE_pdcp_stats[ctxt_pP->module_id].apply_security);
        }
      }

#endif

      /* Print octets of outgoing data in hexadecimal form */
      LOG_D(PDCP, "Following content with size %d will be sent over RLC (PDCP PDU header is the first two bytes)\n",
            pdcp_pdu_size);
      //util_print_hex_octets(PDCP, (unsigned char*)pdcp_pdu_p->data, pdcp_pdu_size);
      //util_flush_hex_octets(PDCP, (unsigned char*)pdcp_pdu->data, pdcp_pdu_size);
    } else {
      LOG_E(PDCP, "Cannot create a mem_block for a PDU!\n");

      if (ctxt_pP->enb_flag == ENB_FLAG_NO) {
        stop_meas(&eNB_pdcp_stats[ctxt_pP->module_id].data_req);
      } else {
        stop_meas(&UE_pdcp_stats[ctxt_pP->module_id].data_req);
      }

#if defined(STOP_ON_IP_TRAFFIC_OVERLOAD)
      AssertFatal(0, "[FRAME %5u][%s][PDCP][MOD %u/%u][RB %u] PDCP_DATA_REQ SDU DROPPED, OUT OF MEMORY \n",
                  ctxt_pP->frame,
                  (ctxt_pP->enb_flag) ? "eNB" : "UE",
                  ctxt_pP->enb_module_id,
                  ctxt_pP->ue_module_id,
                  rb_idP);
#endif
      VCD_SIGNAL_DUMPER_DUMP_FUNCTION_BY_NAME(VCD_SIGNAL_DUMPER_FUNCTIONS_PDCP_DATA_REQ,VCD_FUNCTION_OUT);
      return FALSE;
    }

    /*
     * Ask sublayer to transmit data and check return value
     * to see if RLC succeeded
     */
#ifdef PDCP_MSG_PRINT
    int i=0;
    LOG_F(PDCP,"[MSG] PDCP DL %s PDU on rb_id %d\n", (srb_flagP)? "CONTROL" : "DATA", rb_idP);

    for (i = 0; i < pdcp_pdu_size; i++) {
      LOG_F(PDCP,"%02x ", ((uint8_t*)pdcp_pdu_p->data)[i]);
    }

    LOG_F(PDCP,"\n");
#endif
    rlc_status = rlc_data_req(ctxt_pP, srb_flagP, MBMS_FLAG_NO, rb_idP, muiP, confirmP, pdcp_pdu_size, pdcp_pdu_p);

  }

  switch (rlc_status) {
  case RLC_OP_STATUS_OK:
    LOG_D(PDCP, "Data sending request over RLC succeeded!\n");
    ret=TRUE;
    break;

  case RLC_OP_STATUS_BAD_PARAMETER:
    LOG_W(PDCP, "Data sending request over RLC failed with 'Bad Parameter' reason!\n");
    ret= FALSE;
    break;

  case RLC_OP_STATUS_INTERNAL_ERROR:
    LOG_W(PDCP, "Data sending request over RLC failed with 'Internal Error' reason!\n");
    ret= FALSE;
    break;

  case RLC_OP_STATUS_OUT_OF_RESSOURCES:
    LOG_W(PDCP, "Data sending request over RLC failed with 'Out of Resources' reason!\n");
    ret= FALSE;
    break;

  default:
    LOG_W(PDCP, "RLC returned an unknown status code after PDCP placed the order to send some data (Status Code:%d)\n", rlc_status);
    ret= FALSE;
    break;
  }

  if (ctxt_pP->enb_flag == ENB_FLAG_NO) {
    stop_meas(&eNB_pdcp_stats[ctxt_pP->module_id].data_req);
  } else {
    stop_meas(&UE_pdcp_stats[ctxt_pP->module_id].data_req);
  }

  /*
   * Control arrives here only if rlc_data_req() returns RLC_OP_STATUS_OK
   * so we return TRUE afterwards
   */
  /*
   if (rb_id>=DTCH) {
    if (ctxt_pP->enb_flag == 1) {
      Pdcp_stats_tx[module_id][(rb_id & RAB_OFFSET2 )>> RAB_SHIFT2][(rb_id & RAB_OFFSET)-DTCH]++;
      Pdcp_stats_tx_bytes[module_id][(rb_id & RAB_OFFSET2 )>> RAB_SHIFT2][(rb_id & RAB_OFFSET)-DTCH] += sdu_buffer_size;
    } else {
      Pdcp_stats_tx[module_id][(rb_id & RAB_OFFSET2 )>> RAB_SHIFT2][(rb_id & RAB_OFFSET)-DTCH]++;
      Pdcp_stats_tx_bytes[module_id][(rb_id & RAB_OFFSET2 )>> RAB_SHIFT2][(rb_id & RAB_OFFSET)-DTCH] += sdu_buffer_size;
    }
    }*/
  VCD_SIGNAL_DUMPER_DUMP_FUNCTION_BY_NAME(VCD_SIGNAL_DUMPER_FUNCTIONS_PDCP_DATA_REQ,VCD_FUNCTION_OUT);
  return ret;

}


//-----------------------------------------------------------------------------
boolean_t
pdcp_data_ind(
  const protocol_ctxt_t* const ctxt_pP,
  const srb_flag_t   srb_flagP,
  const MBMS_flag_t  MBMS_flagP,
  const rb_id_t      rb_idP,
  const sdu_size_t   sdu_buffer_sizeP,
  mem_block_t* const sdu_buffer_pP
)
//-----------------------------------------------------------------------------
{
  pdcp_t      *pdcp_p          = NULL;
  list_t      *sdu_list_p      = NULL;
  mem_block_t *new_sdu_p       = NULL;
  uint8_t      pdcp_header_len = 0;
  uint8_t      pdcp_tailer_len = 0;
  pdcp_sn_t    sequence_number = 0;
  volatile sdu_size_t   payload_offset  = 0;
  rb_id_t      rb_id            = rb_idP;
  boolean_t    packet_forwarded = FALSE;
  hash_key_t      key             = HASHTABLE_NOT_A_KEY_VALUE;
  hashtable_rc_t  h_rc;
#if defined(LINK_ENB_PDCP_TO_GTPV1U)
  MessageDef  *message_p        = NULL;
  uint8_t     *gtpu_buffer_p    = NULL;
#endif


  VCD_SIGNAL_DUMPER_DUMP_FUNCTION_BY_NAME(VCD_SIGNAL_DUMPER_FUNCTIONS_PDCP_DATA_IND,VCD_FUNCTION_IN);

#ifdef OAI_EMU

  CHECK_CTXT_ARGS(ctxt_pP);

#endif
#ifdef PDCP_MSG_PRINT
  int i=0;
  LOG_F(PDCP,"[MSG] PDCP UL %s PDU on rb_id %d\n", (srb_flagP)? "CONTROL" : "DATA", rb_idP);

  for (i = 0; i < sdu_buffer_sizeP; i++) {
    LOG_F(PDCP,"%02x ", ((uint8_t*)sdu_buffer_pP->data)[i]);
  }

  LOG_F(PDCP,"\n");
#endif

  if (MBMS_flagP) {
    AssertError (rb_idP < NB_RB_MBMS_MAX, return FALSE,
                 "RB id is too high (%u/%d) %u rnti %x!\n",
                 rb_idP,
                 NB_RB_MBMS_MAX,
                 ctxt_pP->module_id,
                 ctxt_pP->rnti);

    if (ctxt_pP->enb_flag == ENB_FLAG_NO) {
      LOG_D(PDCP, "e-MBMS Data indication notification for PDCP entity from eNB %u to UE %x "
            "and radio bearer ID %d rlc sdu size %d ctxt_pP->enb_flag %d\n",
            ctxt_pP->module_id,
            ctxt_pP->rnti,
            rb_idP,
            sdu_buffer_sizeP,
            ctxt_pP->enb_flag);

      } else {
      LOG_D(PDCP, "Data indication notification for PDCP entity from UE %x to eNB %u "
            "and radio bearer ID %d rlc sdu size %d ctxt_pP->enb_flag %d\n",
            ctxt_pP->rnti,
            ctxt_pP->module_id ,
            rb_idP,
            sdu_buffer_sizeP,
            ctxt_pP->enb_flag);
      }

    } else {
    rb_id = rb_idP % maxDRB;
    AssertError (rb_id < maxDRB, return FALSE, "RB id is too high (%u/%d) %u UE %x!\n",
                 rb_id,
                 maxDRB,
                 ctxt_pP->module_id,
                 ctxt_pP->rnti);
    AssertError (rb_id > 0, return FALSE, "RB id is too low (%u/%d) %u UE %x!\n",
                 rb_id,
                 maxDRB,
                 ctxt_pP->module_id,
                 ctxt_pP->rnti);
    key = PDCP_COLL_KEY_VALUE(ctxt_pP->module_id, ctxt_pP->rnti, ctxt_pP->enb_flag, rb_id, srb_flagP);
    h_rc = hashtable_get(pdcp_coll_p, key, (void**)&pdcp_p);

    if (h_rc != HASH_TABLE_OK) {
      LOG_W(PDCP,
            PROTOCOL_CTXT_FMT"Could not get PDCP instance key 0x%"PRIx64"\n",
            PROTOCOL_CTXT_ARGS(ctxt_pP),
            key);
      free_mem_block(sdu_buffer_pP);
      VCD_SIGNAL_DUMPER_DUMP_FUNCTION_BY_NAME(VCD_SIGNAL_DUMPER_FUNCTIONS_PDCP_DATA_IND,VCD_FUNCTION_OUT);
      return FALSE;
    }
  }

  sdu_list_p = &pdcp_sdu_list;

  if (sdu_buffer_sizeP == 0) {
    LOG_W(PDCP, "SDU buffer size is zero! Ignoring this chunk!\n");
    return FALSE;
  }

  if (ctxt_pP->enb_flag) {
    start_meas(&eNB_pdcp_stats[ctxt_pP->module_id].data_ind);
  } else {
    start_meas(&UE_pdcp_stats[ctxt_pP->module_id].data_ind);
  }

  /*
   * Parse the PDU placed at the beginning of SDU to check
   * if incoming SN is in line with RX window
   */

  if (MBMS_flagP == 0 ) {
    if (srb_flagP) { //SRB1/2
      pdcp_header_len = PDCP_CONTROL_PLANE_DATA_PDU_SN_SIZE;
      pdcp_tailer_len = PDCP_CONTROL_PLANE_DATA_PDU_MAC_I_SIZE;
      sequence_number =   pdcp_get_sequence_number_of_pdu_with_SRB_sn((unsigned char*)sdu_buffer_pP->data);
    } else { // DRB
      pdcp_tailer_len = 0;

      if (pdcp_p->seq_num_size == PDCP_SN_7BIT) {
        pdcp_header_len = PDCP_USER_PLANE_DATA_PDU_SHORT_SN_HEADER_SIZE;
        sequence_number =     pdcp_get_sequence_number_of_pdu_with_short_sn((unsigned char*)sdu_buffer_pP->data);
      } else if (pdcp_p->seq_num_size == PDCP_SN_12BIT) {
        pdcp_header_len = PDCP_USER_PLANE_DATA_PDU_LONG_SN_HEADER_SIZE;
        sequence_number =     pdcp_get_sequence_number_of_pdu_with_long_sn((unsigned char*)sdu_buffer_pP->data);
      } else {
        //sequence_number = 4095;
        LOG_E(PDCP,
              PROTOCOL_PDCP_CTXT_FMT"wrong sequence number  (%d) for this pdcp entity \n",
              PROTOCOL_PDCP_CTXT_ARGS(ctxt_pP, pdcp_p),
              pdcp_p->seq_num_size);
      }

      //uint8_t dc = pdcp_get_dc_filed((unsigned char*)sdu_buffer_pP->data);
    }

    /*
     * Check if incoming SDU is long enough to carry a PDU header
     */
    if (sdu_buffer_sizeP < pdcp_header_len + pdcp_tailer_len ) {
      LOG_W(PDCP,
            PROTOCOL_PDCP_CTXT_FMT"Incoming (from RLC) SDU is short of size (size:%d)! Ignoring...\n",
            PROTOCOL_PDCP_CTXT_ARGS(ctxt_pP, pdcp_p),
            sdu_buffer_sizeP);
      free_mem_block(sdu_buffer_pP);

      if (ctxt_pP->enb_flag) {
        stop_meas(&eNB_pdcp_stats[ctxt_pP->module_id].data_ind);
      } else {
        stop_meas(&UE_pdcp_stats[ctxt_pP->module_id].data_ind);
      }

      VCD_SIGNAL_DUMPER_DUMP_FUNCTION_BY_NAME(VCD_SIGNAL_DUMPER_FUNCTIONS_PDCP_DATA_IND,VCD_FUNCTION_OUT);
      return FALSE;
    }

    if (pdcp_is_rx_seq_number_valid(sequence_number, pdcp_p, srb_flagP) == TRUE) {
#if 0
      LOG_T(PDCP, "Incoming PDU has a sequence number (%d) in accordance with RX window\n", sequence_number);
#endif
      /* if (dc == PDCP_DATA_PDU )
      LOG_D(PDCP, "Passing piggybacked SDU to NAS driver...\n");
      else
      LOG_D(PDCP, "Passing piggybacked SDU to RRC ...\n");*/
    } else {
      LOG_W(PDCP,
            PROTOCOL_PDCP_CTXT_FMT"Incoming PDU has an unexpected sequence number (%d), RX window synchronisation have probably been lost!\n",
            PROTOCOL_PDCP_CTXT_ARGS(ctxt_pP, pdcp_p),
            sequence_number);
      /*
       * XXX Till we implement in-sequence delivery and duplicate discarding
       * mechanism all out-of-order packets will be delivered to RRC/IP
       */
#if 0
      LOG_D(PDCP, "Ignoring PDU...\n");
      free_mem_block(sdu_buffer);
      return FALSE;
#else
      //LOG_W(PDCP, "Delivering out-of-order SDU to upper layer...\n");
#endif
    }

    // SRB1/2: control-plane data
    if (srb_flagP) {
#if defined(ENABLE_SECURITY)

      if (pdcp_p->security_activated == 1) {
        if (ctxt_pP->enb_flag == ENB_FLAG_NO) {
          start_meas(&eNB_pdcp_stats[ctxt_pP->module_id].validate_security);
        } else {
          start_meas(&UE_pdcp_stats[ctxt_pP->module_id].validate_security);
        }

        pdcp_validate_security(ctxt_pP,
                               pdcp_p,
                               srb_flagP,
                               rb_idP,
                               pdcp_header_len,
                               sequence_number,
                               sdu_buffer_pP->data,
                               sdu_buffer_sizeP - pdcp_tailer_len);

        if (ctxt_pP->enb_flag == ENB_FLAG_NO) {
          stop_meas(&eNB_pdcp_stats[ctxt_pP->module_id].validate_security);
        } else {
          stop_meas(&UE_pdcp_stats[ctxt_pP->module_id].validate_security);
        }
      }

#endif
      //rrc_lite_data_ind(module_id, //Modified MW - L2 Interface
      pdcp_rrc_data_ind(ctxt_pP,
                        rb_id,
                        sdu_buffer_sizeP - pdcp_header_len - pdcp_tailer_len,
                        (uint8_t*)&sdu_buffer_pP->data[pdcp_header_len]);
      free_mem_block(sdu_buffer_pP);

      // free_mem_block(new_sdu);
      if (ctxt_pP->enb_flag) {
        stop_meas(&eNB_pdcp_stats[ctxt_pP->module_id].data_ind);
      } else {
        stop_meas(&UE_pdcp_stats[ctxt_pP->module_id].data_ind);
      }

      VCD_SIGNAL_DUMPER_DUMP_FUNCTION_BY_NAME(VCD_SIGNAL_DUMPER_FUNCTIONS_PDCP_DATA_IND,VCD_FUNCTION_OUT);
      return TRUE;
    }

    /*
     * DRBs
     */
    payload_offset=pdcp_header_len;// PDCP_USER_PLANE_DATA_PDU_LONG_SN_HEADER_SIZE;
#if defined(ENABLE_SECURITY)

    if (pdcp_p->security_activated == 1) {
      if (ctxt_pP->enb_flag == ENB_FLAG_NO) {
        start_meas(&eNB_pdcp_stats[ctxt_pP->module_id].validate_security);
      } else {
        start_meas(&UE_pdcp_stats[ctxt_pP->module_id].validate_security);
      }

      pdcp_validate_security(
        ctxt_pP,
        pdcp_p,
        srb_flagP,
        rb_idP,
        pdcp_header_len,
        sequence_number,
        sdu_buffer_pP->data,
        sdu_buffer_sizeP - pdcp_tailer_len);

      if (ctxt_pP->enb_flag == ENB_FLAG_NO) {
        stop_meas(&eNB_pdcp_stats[ctxt_pP->module_id].validate_security);
      } else {
        stop_meas(&UE_pdcp_stats[ctxt_pP->module_id].validate_security);
      }

    }

#endif
  } else {
    payload_offset=0;
  }

#if defined(USER_MODE) && defined(OAI_EMU)

  if (oai_emulation.info.otg_enabled == 1) {
    unsigned int dst_instance;
    int    ctime;

    if (pdcp_p->rlc_mode == RLC_MODE_AM ) {
      pdcp_p->last_submitted_pdcp_rx_sn = sequence_number;
    }

#if defined(DEBUG_PDCP_PAYLOAD)
    rlc_util_print_hex_octets(PDCP,
                              (unsigned char*)&sdu_buffer_pP->data[payload_offset],
                              sdu_buffer_sizeP - payload_offset);
#endif

    ctime = oai_emulation.info.time_ms; // avg current simulation time in ms : we may get the exact time through OCG?
    LOG_D(PDCP,
          PROTOCOL_PDCP_CTXT_FMT"Check received buffer :  (dst %d)\n",
          PROTOCOL_PDCP_CTXT_ARGS(ctxt_pP, pdcp_p),
          ctxt_pP->instance);

    if (otg_rx_pkt(
          ctxt_pP->instance,
          ctime,
          (const char*)(&sdu_buffer_pP->data[payload_offset]),
                   sdu_buffer_sizeP - payload_offset ) == 0 ) {
      free_mem_block(sdu_buffer_pP);

      if (ctxt_pP->enb_flag) {
        stop_meas(&eNB_pdcp_stats[ctxt_pP->module_id].data_ind);
      } else {
        stop_meas(&UE_pdcp_stats[ctxt_pP->module_id].data_ind);
      }

      VCD_SIGNAL_DUMPER_DUMP_FUNCTION_BY_NAME(VCD_SIGNAL_DUMPER_FUNCTIONS_PDCP_DATA_IND,VCD_FUNCTION_OUT);
      return TRUE;
    }
  }

#else

  if (otg_enabled==1) {
    LOG_D(OTG,"Discarding received packed\n");
    free_mem_block(sdu_buffer_pP);

    if (ctxt_pP->enb_flag) {
      stop_meas(&eNB_pdcp_stats[ctxt_pP->module_id].data_ind);
    } else {
      stop_meas(&UE_pdcp_stats[ctxt_pP->module_id].data_ind);
    }

    VCD_SIGNAL_DUMPER_DUMP_FUNCTION_BY_NAME(VCD_SIGNAL_DUMPER_FUNCTIONS_PDCP_DATA_IND,VCD_FUNCTION_OUT);
    return TRUE;
  }

#endif


  // XXX Decompression would be done at this point

  /*
   * After checking incoming sequence number PDCP header
   * has to be stripped off so here we copy SDU buffer starting
   * from its second byte (skipping 0th and 1st octets, i.e.
   * PDCP header)
   */
#if defined(LINK_ENB_PDCP_TO_GTPV1U)

  if ((TRUE == ctxt_pP->enb_flag) && (FALSE == srb_flagP)) {
    //LOG_T(PDCP,"Sending to GTPV1U %d bytes\n", sdu_buffer_sizeP - payload_offset);
    gtpu_buffer_p = itti_malloc(TASK_PDCP_ENB, TASK_GTPV1_U,
                                sdu_buffer_sizeP - payload_offset + GTPU_HEADER_OVERHEAD_MAX);
    AssertFatal(gtpu_buffer_p != NULL, "OUT OF MEMORY");
    memcpy(&gtpu_buffer_p[GTPU_HEADER_OVERHEAD_MAX], &sdu_buffer_pP->data[payload_offset], sdu_buffer_sizeP - payload_offset);
    message_p = itti_alloc_new_message(TASK_PDCP_ENB, GTPV1U_ENB_TUNNEL_DATA_REQ);
    AssertFatal(message_p != NULL, "OUT OF MEMORY");
    GTPV1U_ENB_TUNNEL_DATA_REQ(message_p).buffer       = gtpu_buffer_p;
    GTPV1U_ENB_TUNNEL_DATA_REQ(message_p).length       = sdu_buffer_sizeP - payload_offset;
    GTPV1U_ENB_TUNNEL_DATA_REQ(message_p).offset       = GTPU_HEADER_OVERHEAD_MAX;
    GTPV1U_ENB_TUNNEL_DATA_REQ(message_p).rnti         = ctxt_pP->rnti;
    GTPV1U_ENB_TUNNEL_DATA_REQ(message_p).rab_id       = rb_id + 4;
    itti_send_msg_to_task(TASK_GTPV1_U, INSTANCE_DEFAULT, message_p);
    packet_forwarded = TRUE;
  }

#else
  packet_forwarded = FALSE;
#endif

  if (FALSE == packet_forwarded) {
    new_sdu_p = get_free_mem_block(sdu_buffer_sizeP - payload_offset + sizeof (pdcp_data_ind_header_t));

    if (new_sdu_p) {
      if (pdcp_p->rlc_mode == RLC_MODE_AM ) {
        pdcp_p->last_submitted_pdcp_rx_sn = sequence_number;
      }

      /*
       * Prepend PDCP indication header which is going to be removed at pdcp_fifo_flush_sdus()
       */
      memset(new_sdu_p->data, 0, sizeof (pdcp_data_ind_header_t));
      ((pdcp_data_ind_header_t *) new_sdu_p->data)->data_size = sdu_buffer_sizeP - payload_offset;

      // Here there is no virtualization possible
      // set ((pdcp_data_ind_header_t *) new_sdu_p->data)->inst for IP layer here
      if (ctxt_pP->enb_flag == ENB_FLAG_NO) {
        ((pdcp_data_ind_header_t *) new_sdu_p->data)->rb_id = rb_id;
#if defined(OAI_EMU)
        ((pdcp_data_ind_header_t*) new_sdu_p->data)->inst  = ctxt_pP->module_id + oai_emulation.info.nb_enb_local - oai_emulation.info.first_ue_local;
#endif
      } else {
        ((pdcp_data_ind_header_t*) new_sdu_p->data)->rb_id = rb_id + (ctxt_pP->module_id * maxDRB);
#if defined(OAI_EMU)
        ((pdcp_data_ind_header_t*) new_sdu_p->data)->inst  = ctxt_pP->module_id - oai_emulation.info.first_enb_local;
#endif
      }

      memcpy(&new_sdu_p->data[sizeof (pdcp_data_ind_header_t)], \
             &sdu_buffer_pP->data[payload_offset], \
             sdu_buffer_sizeP - payload_offset);
      list_add_tail_eurecom (new_sdu_p, sdu_list_p);

      /* Print octets of incoming data in hexadecimal form */
      LOG_D(PDCP, "Following content has been received from RLC (%d,%d)(PDCP header has already been removed):\n",
            sdu_buffer_sizeP  - payload_offset + sizeof(pdcp_data_ind_header_t),
            sdu_buffer_sizeP  - payload_offset);
      //util_print_hex_octets(PDCP, &new_sdu_p->data[sizeof (pdcp_data_ind_header_t)], sdu_buffer_sizeP - payload_offset);
      //util_flush_hex_octets(PDCP, &new_sdu_p->data[sizeof (pdcp_data_ind_header_t)], sdu_buffer_sizeP - payload_offset);

      /*
       * Update PDCP statistics
       * XXX Following two actions are identical, is there a merge error?
       */

      /*if (ctxt_pP->enb_flag == 1) {
          Pdcp_stats_rx[module_id][(rb_idP & RAB_OFFSET2) >> RAB_SHIFT2][(rb_idP & RAB_OFFSET) - DTCH]++;
          Pdcp_stats_rx_bytes[module_id][(rb_idP & RAB_OFFSET2) >> RAB_SHIFT2][(rb_idP & RAB_OFFSET) - DTCH] += sdu_buffer_sizeP;
        } else {
          Pdcp_stats_rx[module_id][(rb_idP & RAB_OFFSET2) >> RAB_SHIFT2][(rb_idP & RAB_OFFSET) - DTCH]++;
          Pdcp_stats_rx_bytes[module_id][(rb_idP & RAB_OFFSET2) >> RAB_SHIFT2][(rb_idP & RAB_OFFSET) - DTCH] += sdu_buffer_sizeP;
        }*/
    }
  }

#if defined(STOP_ON_IP_TRAFFIC_OVERLOAD)
  else {
    AssertFatal(0, PROTOCOL_PDCP_CTXT_FMT" PDCP_DATA_IND SDU DROPPED, OUT OF MEMORY \n",
                PROTOCOL_PDCP_CTXT_ARGS(ctxt_pP, pdcp_p));
  }

#endif

  free_mem_block(sdu_buffer_pP);

  if (ctxt_pP->enb_flag) {
    stop_meas(&eNB_pdcp_stats[ctxt_pP->module_id].data_ind);
  } else {
    stop_meas(&UE_pdcp_stats[ctxt_pP->module_id].data_ind);
  }

  VCD_SIGNAL_DUMPER_DUMP_FUNCTION_BY_NAME(VCD_SIGNAL_DUMPER_FUNCTIONS_PDCP_DATA_IND,VCD_FUNCTION_OUT);
  return TRUE;
}

//-----------------------------------------------------------------------------
void
pdcp_run (
  const protocol_ctxt_t* const  ctxt_pP
)
//-----------------------------------------------------------------------------
{
#if defined(ENABLE_ITTI)
  MessageDef   *msg_p;
  const char   *msg_name;
  instance_t    instance;
  int           result;
  protocol_ctxt_t  ctxt;
#endif

  if (ctxt_pP->enb_flag) {
    start_meas(&eNB_pdcp_stats[ctxt_pP->module_id].pdcp_run);
  } else {
    start_meas(&UE_pdcp_stats[ctxt_pP->module_id].pdcp_run);
  }

  VCD_SIGNAL_DUMPER_DUMP_FUNCTION_BY_NAME(VCD_SIGNAL_DUMPER_FUNCTIONS_PDCP_RUN, VCD_FUNCTION_IN);

#if defined(ENABLE_ITTI)

  do {
    // Checks if a message has been sent to PDCP sub-task
    itti_poll_msg (ctxt_pP->enb_flag ? TASK_PDCP_ENB : TASK_PDCP_UE, &msg_p);

    if (msg_p != NULL) {
      msg_name = ITTI_MSG_NAME (msg_p);
      instance = ITTI_MSG_INSTANCE (msg_p);

      switch (ITTI_MSG_ID(msg_p)) {
      case RRC_DCCH_DATA_REQ:
        PROTOCOL_CTXT_SET_BY_MODULE_ID(
          &ctxt,
          RRC_DCCH_DATA_REQ (msg_p).module_id,
          RRC_DCCH_DATA_REQ (msg_p).enb_flag,
          RRC_DCCH_DATA_REQ (msg_p).rnti,
          RRC_DCCH_DATA_REQ (msg_p).frame, 0);
        LOG_D(PDCP, PROTOCOL_CTXT_FMT"Received %s from %s: instance %d, rb_id %d, muiP %d, confirmP %d, mode %d\n",
              PROTOCOL_CTXT_ARGS(&ctxt),
              msg_name,
              ITTI_MSG_ORIGIN_NAME(msg_p),
              instance,
              RRC_DCCH_DATA_REQ (msg_p).rb_id,
              RRC_DCCH_DATA_REQ (msg_p).muip,
              RRC_DCCH_DATA_REQ (msg_p).confirmp,
              RRC_DCCH_DATA_REQ (msg_p).mode);

        result = pdcp_data_req (&ctxt,
                                SRB_FLAG_YES,
                                RRC_DCCH_DATA_REQ (msg_p).rb_id,
                                RRC_DCCH_DATA_REQ (msg_p).muip,
                                RRC_DCCH_DATA_REQ (msg_p).confirmp,
                                RRC_DCCH_DATA_REQ (msg_p).sdu_size,
                                RRC_DCCH_DATA_REQ (msg_p).sdu_p,
                                RRC_DCCH_DATA_REQ (msg_p).mode);
        AssertFatal (result == TRUE, "PDCP data request failed!\n");

        // Message buffer has been processed, free it now.
        result = itti_free (ITTI_MSG_ORIGIN_ID(msg_p), RRC_DCCH_DATA_REQ (msg_p).sdu_p);
        AssertFatal (result == EXIT_SUCCESS, "Failed to free memory (%d)!\n", result);
        break;

      default:
        LOG_E(PDCP, "Received unexpected message %s\n", msg_name);
        break;
      }

      result = itti_free (ITTI_MSG_ORIGIN_ID(msg_p), msg_p);
      AssertFatal (result == EXIT_SUCCESS, "Failed to free memory (%d)!\n", result);
    }
  } while(msg_p != NULL);

# if 0
  {
    MessageDef *msg_resp_p;

    msg_resp_p = itti_alloc_new_message(TASK_PDCP_ENB, MESSAGE_TEST);

    itti_send_msg_to_task(TASK_RRC_ENB, 1, msg_resp_p);
  }
  {
    MessageDef *msg_resp_p;

    msg_resp_p = itti_alloc_new_message(TASK_PDCP_ENB, MESSAGE_TEST);

    itti_send_msg_to_task(TASK_ENB_APP, 2, msg_resp_p);
  }
  {
    MessageDef *msg_resp_p;

    msg_resp_p = itti_alloc_new_message(TASK_PDCP_ENB, MESSAGE_TEST);

    itti_send_msg_to_task(TASK_MAC_ENB, 3, msg_resp_p);
  }
# endif
#endif

#if defined(USER_MODE) && defined(OAI_EMU)
    pdcp_fifo_read_input_sdus_from_otg(ctxt_pP);

#endif

  // IP/NAS -> PDCP traffic : TX, read the pkt from the upper layer buffer
#if defined(LINK_ENB_PDCP_TO_GTPV1U)

  if (ctxt_pP->enb_flag == ENB_FLAG_NO)
#endif
  {
    pdcp_fifo_read_input_sdus(ctxt_pP);
  }

  // PDCP -> NAS/IP traffic: RX
  if (ctxt_pP->enb_flag) {
    start_meas(&eNB_pdcp_stats[ctxt_pP->module_id].pdcp_ip);
  }</