view src/g23m-gprs/sndcp/sndcp_nuf.c @ 220:0ed36de51973

ABB semaphore protection overhaul The ABB semaphone protection logic that came with TCS211 from TI was broken in several ways: * Some semaphore-protected functions were called from Application_Initialize() context. NU_Obtain_Semaphore() called with NU_SUSPEND fails with NU_INVALID_SUSPEND in this context, but the return value wasn't checked, and NU_Release_Semaphore() would be called unconditionally at the end. The latter call would increment the semaphore count past 1, making the semaphore no longer binary and thus no longer effective for resource protection. The fix is to check the return value from NU_Obtain_Semaphore() and skip the NU_Release_Semaphore() call if the semaphore wasn't properly obtained. * Some SPI hardware manipulation was being done before entering the semaphore- protected critical section. The fix is to reorder the code: first obtain the semaphore, then do everything else. * In the corner case of L1/DSP recovery, l1_abb_power_on() would call some non-semaphore-protected ABB & SPI init functions. The fix is to skip those calls in the case of recovery. * A few additional corner cases existed, all of which are fixed by making ABB semaphore protection 100% consistent for all ABB functions and code paths. There is still one remaining problem of priority inversion: suppose a low- priority task calls an ABB function, and some medium-priority task just happens to preempt right in the middle of that semaphore-protected ABB operation. Then the high-priority SPI task is locked out for a non-deterministic time until that medium-priority task finishes its work and goes back to sleep. This priority inversion problem remains outstanding for now.
author Mychaela Falconia <falcon@freecalypso.org>
date Mon, 26 Apr 2021 20:55:25 +0000
parents fa8dc04885d8
children
line wrap: on
line source

/*
+-----------------------------------------------------------------------------
|  Project :  GPRS (8441)
|  Modul   :  sndcp_nuf.c
+-----------------------------------------------------------------------------
|  Copyright 2002 Texas Instruments Berlin, AG
|                 All rights reserved.
|
|                 This file is confidential and a trade secret of Texas
|                 Instruments Berlin, AG
|                 The receipt of or possession of this file does not convey
|                 any rights to reproduce or disclose its contents or to
|                 manufacture, use, or sell anything it may describe, in
|                 whole, or in part, without the specific written consent of
|                 Texas Instruments Berlin, AG.
+-----------------------------------------------------------------------------
|  Purpose :  This modul is part of the entity SNDCP and implements all
|             procedures and functions as described in the
|             SDL-documentation (NU-statemachine)
+-----------------------------------------------------------------------------
*/

/*---- HISTORY --------------------------------------------------------------*/
#define ENTITY_SNDCP

/*==== INCLUDES =============================================================*/

#include "typedefs.h"    /* to get Condat data types */
#include "vsi.h"        /* to get a lot of macros */
#include "macdef.h"
#include "gsm.h"        /* to get a lot of macros */
#include "prim.h"       /* to get the definitions of used SAP and directions */

#include "dti.h"

#include "sndcp.h"        /* to get the global entity definitions */
#include "sndcp_f.h"       /* to get the functions to access the global arrays*/

#ifndef NCONFIG
#include "sndcp_nuf.h"
#include "sndcp_suas.h"
#include "sndcp_sus.h"
#endif

/*==== CONST ================================================================*/

/*==== LOCAL VARS ===========================================================*/

/*==== PRIVATE FUNCTIONS ====================================================*/

LOCAL void nu_delete (T_NPDU_BUFFER* npdu_buffer);


/*
+------------------------------------------------------------------------------
| Function    : nu_delete
+------------------------------------------------------------------------------
| Description : The function nu_delete() deletes one buffered N-PDU.
|               It is used to delete one N-PDU in form of an SN_DATA_REQ
|               pointer.
|               It will be useful when one N-PDU is deleted in case of
|               LL_DATA_CNF orwhen every N-PDU for one NSAPI is deleted in case
|               of SIG_MG_DELETE_NPDUS.
|               First every descriptor in the SN_DATA_REQ is deleted, then the
|               primitive is deleted, then the T_NPDU_BUFFER* is deleted. (This
|               type is only specified in the code.)
| Parameter   : the one N-PDU to be deleted.
|
+------------------------------------------------------------------------------
*/
LOCAL void nu_delete (T_NPDU_BUFFER* npdu_buffer)
{

  TRACE_FUNCTION( "nu_delete" );

  if (npdu_buffer == NULL) {
    return;
  }
  /*
   * Free the SN_DATA_REQ.
   */
#ifdef _SNDCP_DTI_2_
  if (npdu_buffer->sn_data_req != NULL) {
    MFREE_PRIM(npdu_buffer->sn_data_req);
    npdu_buffer->sn_data_req = NULL;
  }
#else /*_SNDCP_DTI_2_*/
  if (npdu_buffer->sn_data_req != NULL) {
    PFREE_DESC(npdu_buffer->sn_data_req);
    npdu_buffer->sn_data_req = NULL;
  }
#endif /*_SNDCP_DTI_2_*/
  /*
   * If this was the next to send in recovery state, move to next now.
   */
  if (npdu_buffer == sndcp_data->nu->next_resend) {
    sndcp_data->nu->next_resend = npdu_buffer->next;
  }
  if (npdu_buffer == sndcp_data->nu->first_buffered_npdu) {
    sndcp_data->nu->first_buffered_npdu = npdu_buffer->next;
  }
  /*
   * Free the T_NPDU_BUFFER
   */
  MFREE(npdu_buffer);
  npdu_buffer = NULL;
} /* nu_delete() */


/*==== PUBLIC FUNCTIONS =====================================================*/




/*
+------------------------------------------------------------------------------
| Function    : nu_buffer_npdu
+------------------------------------------------------------------------------
| Description : The function nu_buffer_npdu() buffers the given SN_DATA_REQ
|               together with the given N-PDU number.
|
| Parameters  : N-PDU number, SN_DATA_REQ primitive.
|
+------------------------------------------------------------------------------
*/
GLOBAL void nu_buffer_npdu (UBYTE npdu_number, T_SN_DATA_REQ* sn_data_req)
{
  T_NPDU_BUFFER* npdu_buffer = 0;

  TRACE_FUNCTION( "nu_buffer_npdu" );

  /*
   * Allocate the T_NPDU_BUFFER struct for
   */
  MALLOC(npdu_buffer, sizeof(T_NPDU_BUFFER));
  /*
   * Insert the given values.
   */
  npdu_buffer->npdu_number = npdu_number;
  npdu_buffer->sn_data_req = sn_data_req;
  npdu_buffer->next = NULL;
  if (sndcp_data->nu->first_buffered_npdu == NULL) {
    sndcp_data->nu->first_buffered_npdu = npdu_buffer;
    sndcp_data->nu->next_resend = npdu_buffer;
  } else {
    T_NPDU_BUFFER* help = sndcp_data->nu->first_buffered_npdu;

    if (help->next == NULL) {
      help->next = npdu_buffer;
    } else {
      while (help->next != NULL) {
        help = help->next;
      }
      help->next = npdu_buffer;
    }

  }


} /* nu_buffer_npdu() */

#ifndef NCONFIG

/*
+------------------------------------------------------------------------------
| Function    : nu_config_discard
+------------------------------------------------------------------------------
| Description : reaction to config prim
|
| Parameters  : nsapi
|
+------------------------------------------------------------------------------
*/
GLOBAL void nu_config_discard (UBYTE nsapi)
{
  TRACE_FUNCTION( "nu_config_discard" );

  sndcp_data->nu = &sndcp_data->nu_base[nsapi];
  sndcp_data->nu->discard = TRUE;
}

/*
+------------------------------------------------------------------------------
| Function    : nu_config_resume
+------------------------------------------------------------------------------
| Description : reaction to config prim
|
| Parameters  : nsapi
|
+------------------------------------------------------------------------------
*/
GLOBAL void nu_config_resume (UBYTE nsapi)
{
  TRACE_FUNCTION( "nu_config_resume" );

  sndcp_data->nu = &sndcp_data->nu_base[nsapi];
  sndcp_data->nu->discard = FALSE;
}

/*
+------------------------------------------------------------------------------
| Function    : nu_config_send
+------------------------------------------------------------------------------
| Description : reaction to config prim
|
| Parameters  : nsapi, number of octets
|
+------------------------------------------------------------------------------
*/
GLOBAL void nu_config_send (UBYTE nsapi, U32 octets)
{
  U32 *data_count = NULL;

  TRACE_FUNCTION( "nu_config_send" );

  sndcp_data->nu = &sndcp_data->nu_base[nsapi];
  
  data_count = &sndcp_data->data_count[nsapi];

  if (*data_count == 0) {
    *data_count = octets;
  } else {
    *data_count += octets;
    return;
  }

  switch( GET_STATE( NU ) )
  {
    case NU_ACK_SUA_RECEPTIVE:
    case NU_SEND_ACK_SUA_RECEPTIVE:
      SET_STATE(NU, NU_SEND_ACK_SUA_NOT_RECEPTIVE);
      nu_config_send_next(nsapi);
      sndcp_data->nu->sn_ready_ind_pending = FALSE;
      break;
    case NU_ACK_SUA_NOT_RECEPTIVE:
      SET_STATE(NU, NU_SEND_ACK_SUA_NOT_RECEPTIVE);
      break;
    case NU_SEND_ACK_SUA_NOT_RECEPTIVE:
      SET_STATE(NU, NU_SEND_ACK_SUA_NOT_RECEPTIVE);
      *data_count += octets;
      sndcp_data->nu->sn_ready_ind_pending = FALSE;
      break;
    case NU_UNACK_SU_NOT_RECEPTIVE:
      SET_STATE(NU, NU_SEND_UNACK_SU_NOT_RECEPTIVE);
      break;
    case NU_SEND_UNACK_SU_NOT_RECEPTIVE:
      SET_STATE(NU, NU_SEND_UNACK_SU_NOT_RECEPTIVE);
      *data_count += octets;
      sndcp_data->nu->sn_unitready_ind_pending = FALSE;
      break;
    case NU_UNACK_SU_RECEPTIVE:
    case NU_SEND_UNACK_SU_RECEPTIVE:
      SET_STATE(NU, NU_SEND_UNACK_SU_NOT_RECEPTIVE);
      nu_config_send_next(nsapi);
      sndcp_data->nu->sn_unitready_ind_pending = FALSE;
      break;
    case NU_REC_SUA_NOT_RECEPTIVE:
      SET_STATE(NU, NU_SEND_REC_SUA_NOT_RECEPTIVE);
      break;
    case NU_SEND_REC_SUA_NOT_RECEPTIVE:
      break;
    case NU_SUS_SUA_NOT_RECEPTIVE:
      SET_STATE(NU, NU_SEND_SUS_SUA_NOT_RECEPTIVE);
      break;
    case NU_SEND_SUS_SUA_NOT_RECEPTIVE:
      break;
    case NU_SUS_SUA_RECEPTIVE:
      SET_STATE(NU, NU_SEND_SUS_SUA_RECEPTIVE);
      break;
    case NU_SEND_SUS_SUA_RECEPTIVE:
      break;

    default:
      TRACE_ERROR( "config prim SEND unexpected" );
      break;
  }


} /* nu_config_send() */

/*
+------------------------------------------------------------------------------
| Function    : nu_config_send_next
+------------------------------------------------------------------------------
| Description : sends data with 'data_count' octets. State is not changed.
|
| Parameters  : nsapi
| Pre         : data_count > 0
|
+------------------------------------------------------------------------------
*/
GLOBAL void nu_config_send_next (UBYTE nsapi)
{
  BOOL ack = FALSE;
  /*
   * Index and number in pattern.
   */
  USHORT i = 0;
  USHORT r = 0;
  UBYTE sapi = 0;
  USHORT k    = 0;
  UBYTE sapi_index = 0;
  USHORT send_size = 0;
  U16 ip_size = 0;
  U32 length;
  U32* data_count = NULL;
#ifdef _SNDCP_DTI_2_
  T_desc2* desc = NULL,*help;
#else /*_SNDCP_DTI_2_*/
  T_desc* desc = NULL;
#endif /*_SNDCP_DTI_2_*/

  T_SN_DATA_REQ* sn_data_req = NULL;
  T_SN_UNITDATA_REQ* sn_unitdata_req = NULL;

  data_count = &sndcp_data->data_count[nsapi];
  length = *data_count;

  TRACE_FUNCTION( "nu_config_send_next" );

  if (length == 0) {
    sndcp_get_nsapi_ack(nsapi, &ack);
    if (ack) {
      SET_STATE(NU, NU_SEND_ACK_SUA_RECEPTIVE);
    } else {
      SET_STATE(NU, NU_SEND_UNACK_SU_RECEPTIVE);
    }
    return;
  }

  sndcp_get_nsapi_sapi(sndcp_data->nu->nsapi, &sapi);
  sndcp_get_sapi_index(sapi, &sapi_index);

  sndcp_data->nu = &sndcp_data->nu_base[nsapi];
  sndcp_get_nsapi_ack(nsapi, &ack);

  if (ack) {
    send_size =
      sndcp_data->sua_base[sapi_index].n201_i - SN_DATA_PDP_HDR_LEN_BIG;
    TRACE_EVENT_P1("send_size: %d", send_size);
  } else {
    send_size =
      sndcp_data->su_base[sapi_index].n201_u - SN_UNITDATA_PDP_HDR_LEN_BIG;
    TRACE_EVENT_P1("send_size: %d", send_size);
  }

  /*
   * The amount of data to be segmented
   * shall be a multiple of N201_I or N201_U respectively
   */
  if(ack)
  {
    ip_size = 2 * sndcp_data->sua_base[sapi_index].n201_i + 100;
    if (length > ip_size)
    {
      if ( sndcp_data->sua_base[sapi_index].n201_i < ip_size)
      {
        k = (ip_size - (ip_size % 
             sndcp_data->sua_base[sapi_index].n201_i))/
             sndcp_data->sua_base[sapi_index].n201_i;
        length = k * (sndcp_data->sua_base[sapi_index].n201_i)
                 -(k-1)- SN_DATA_PDP_HDR_LEN_BIG;
      }
      else
      {
        length = sndcp_data->sua_base[sapi_index].n201_i - 
                 SN_DATA_PDP_HDR_LEN_BIG;
      }
    }
  }
  else
  {
    ip_size = 2 * sndcp_data->su_base[sapi_index].n201_u + 100;
    if (length > ip_size)
    {
      if ( sndcp_data->su_base[sapi_index].n201_u < ip_size)
      {
        k = (ip_size - (ip_size % 
             sndcp_data->su_base[sapi_index].n201_u))/
             sndcp_data->su_base[sapi_index].n201_u;
        length = k * (sndcp_data->su_base[sapi_index].n201_u) 
                 - (k * (SN_UNITDATA_PDP_HDR_LEN_BIG -1) +1);
      }
      else
      {
        length = sndcp_data->su_base[sapi_index].n201_u - 
                 SN_UNITDATA_PDP_HDR_LEN_BIG;
      }
    }
  }

  TRACE_EVENT_P2("data to segment: %d, data to send: %d", 
                  length, *data_count);

  *data_count -= length;

  /*
   * Allocates small segments
   */
  k = (U16)(length / 100); /* Number of 'full' 100 byte descriptors*/
  r = (U16)(length % 100); /* Number of rest bytes */

  if(r > 0){
#ifdef _SNDCP_DTI_2_
    MALLOC (desc, (USHORT)(sizeof(T_desc2) - 1 + r));
#else /*_SNDCP_DTI_2_*/
    MALLOC (desc, (USHORT)(sizeof(T_desc) - 1 + r));
#endif /*_SNDCP_DTI_2_*/

  desc->next  = (ULONG)NULL;
  desc->len   = r;

#ifdef _SNDCP_DTI_2_
  desc->offset = 0;
  desc->size = r;
#endif
  }

  for ( i=0; i < k; i++){
    /*
     * Allocate memory for descriptor
     */
    MALLOC (help, (USHORT)(sizeof(T_desc2) - 1 + 100));




    /*
     * Fill descriptor control information.
     */
    help->next  = (ULONG)desc;
    help->len   = 100;
    help->offset = 0;
    help->size = help->len;

    desc = help;
  } /* for k */



  if (ack) {
#ifdef _SNDCP_DTI_2_    
    MALLOC(sn_data_req, sizeof(T_SN_DATA_REQ));
    sn_data_req->desc_list2.first = (ULONG) desc;
    sn_data_req->desc_list2.list_len = (U16)length;
#else /*_SNDCP_DTI_2_*/
    PALLOC_DESC (sn_data_req, SN_DATA_REQ);
    sn_data_req->desc_list.first = (ULONG) desc;
    sn_data_req->desc_list.list_len = (U16)length;
#endif /*_SNDCP_DTI_2_*/


    sn_data_req->nsapi = nsapi;
#ifdef SNDCP_UPM_INCLUDED 
    sn_data_req->p_id = DTI_PID_IP;
#else
    sn_data_req->p_id = PPP_PID_IP;
#endif /*SNDCP_UPM_INCLUDED*/
    /*
     * Buffer the given N-PDU
     */
    nu_buffer_npdu(sndcp_data->nu->send_npdu_number_ack, sn_data_req);

    sndcp_data->nu->send_npdu_number_ack =
      (U8)((sndcp_data->nu->send_npdu_number_ack + 1) % MAX_NPDU_NUMBER_ACK);
    sig_nu_sua_data_req(sn_data_req,
                       (U8)((sndcp_data->nu->send_npdu_number_ack - 1
                       + MAX_NPDU_NUMBER_ACK) % MAX_NPDU_NUMBER_ACK),
                       sn_data_req->nsapi,
                       sapi);


  } else {
#ifdef _SNDCP_DTI_2_
    MALLOC(sn_unitdata_req, sizeof(T_SN_UNITDATA_REQ));
    sn_unitdata_req->desc_list2.first = (ULONG) desc;
    sn_unitdata_req->desc_list2.list_len = (U16)length;
#else /*_SNDCP_DTI_2_*/
    PALLOC_DESC (sn_unitdata_req, SN_UNITDATA_REQ);
    sn_unitdata_req->desc_list.first = (ULONG) desc;
    sn_unitdata_req->desc_list.list_len = (U16)length;
#endif /*_SNDCP_DTI_2_*/
    sn_unitdata_req->nsapi = nsapi;
#ifdef SNDCP_UPM_INCLUDED 
    sn_unitdata_req->p_id = DTI_PID_IP;
#else
    sn_unitdata_req->p_id = PPP_PID_IP;
#endif /*SNDCP_UPM_INCLUDED*/

    sndcp_data->nu->send_npdu_number_unack =
      (sndcp_data->nu->send_npdu_number_unack + 1) % MAX_NPDU_NUMBER_UNACK;
    sig_nu_su_unitdata_req(sn_unitdata_req,
                           (U16)((sndcp_data->nu->send_npdu_number_unack - 1
                           + MAX_NPDU_NUMBER_UNACK) % MAX_NPDU_NUMBER_UNACK),
                           sndcp_data->nu->nsapi,
                           sapi);

  }

} /* nu_config_send_next() */

#endif



/*
+------------------------------------------------------------------------------
| Function    : nu_delete_npdu
+------------------------------------------------------------------------------
| Description : The function nu_delete_npdu() searches and deletes one
|               buffered N-PDU.
| Parameter   : nsapi, npdu_number.
| Pre         : correct nu instance must be active, NPDU must exist.
|
+------------------------------------------------------------------------------
*/
GLOBAL void nu_delete_npdu (UBYTE nsapi, UBYTE npdu_number)
{
  T_NPDU_BUFFER* npdu_buffer = NULL;
  T_NPDU_BUFFER* pre = NULL;
  BOOL found = FALSE;

  TRACE_FUNCTION( "nu_delete_npdu" );

  /*
   * Find the npdu.
   */
  npdu_buffer = sndcp_data->nu->first_buffered_npdu;
  while (!found && npdu_buffer != NULL) {
    if (sndcp_data->nu->nsapi == nsapi &&
        npdu_buffer->npdu_number == npdu_number)
    {
      found = TRUE;
      if (pre != NULL) {
        pre->next = npdu_buffer->next;
      }
    } else {
      pre = npdu_buffer;
      npdu_buffer = npdu_buffer->next;
    }
  }
  /*
   * Delete it.
   */
  if (npdu_buffer != NULL) {
    nu_delete(npdu_buffer);
  }
} /* nu_delete_npdu() */



/*
+------------------------------------------------------------------------------
| Function    : nu_delete_npdus
+------------------------------------------------------------------------------
| Description : The function nu_delete_npdus() deletes all buffered N-PDUs.
|
| Pre         : The correct nu instance has to be "active".
|
+------------------------------------------------------------------------------
*/
GLOBAL void nu_delete_npdus (void)
{
  T_NPDU_BUFFER* help = NULL;

  TRACE_FUNCTION( "nu_delete_npdus" );

  while (sndcp_data->nu->first_buffered_npdu != NULL) {
    help = sndcp_data->nu->first_buffered_npdu->next;
    /*
     * Delete the first one.
     */
    nu_delete(sndcp_data->nu->first_buffered_npdu);
    /*
     * Go to the next.
     */
    sndcp_data->nu->first_buffered_npdu = help;
  }
  sndcp_data->nu->next_resend = NULL;

} /* nu_delete_npdus() */


/*
+------------------------------------------------------------------------------
| Function    : nu_init
+------------------------------------------------------------------------------
| Description : The function nu_init() ....
|
| Parameters  :
|
+------------------------------------------------------------------------------
*/
GLOBAL void nu_init (void)
{

  UBYTE nsapi = 0;

  TRACE_FUNCTION( "nu_init" );

  sndcp_data->nu = & sndcp_data->nu_base[0];
  INIT_STATE(NU_0, NU_UNACK_SU_RECEPTIVE);

  sndcp_data->nu = & sndcp_data->nu_base[1];
  INIT_STATE(NU_1, NU_UNACK_SU_RECEPTIVE);

  sndcp_data->nu = & sndcp_data->nu_base[2];
  INIT_STATE(NU_2, NU_UNACK_SU_RECEPTIVE);

  sndcp_data->nu = & sndcp_data->nu_base[3];
  INIT_STATE(NU_3, NU_UNACK_SU_RECEPTIVE);

  sndcp_data->nu = & sndcp_data->nu_base[4];
  INIT_STATE(NU_4, NU_UNACK_SU_RECEPTIVE);

  sndcp_data->nu = & sndcp_data->nu_base[5];
  INIT_STATE(NU_5, NU_UNACK_SU_RECEPTIVE);

  sndcp_data->nu = & sndcp_data->nu_base[6];
  INIT_STATE(NU_6, NU_UNACK_SU_RECEPTIVE);

  sndcp_data->nu = & sndcp_data->nu_base[7];
  INIT_STATE(NU_7, NU_UNACK_SU_RECEPTIVE);

  sndcp_data->nu = & sndcp_data->nu_base[8];
  INIT_STATE(NU_8, NU_UNACK_SU_RECEPTIVE);

  sndcp_data->nu = & sndcp_data->nu_base[9];
  INIT_STATE(NU_9, NU_UNACK_SU_RECEPTIVE);

  sndcp_data->nu = & sndcp_data->nu_base[10];
  INIT_STATE(NU_10, NU_UNACK_SU_RECEPTIVE);

  sndcp_data->nu = & sndcp_data->nu_base[11];
  INIT_STATE(NU_11, NU_UNACK_SU_RECEPTIVE);

  sndcp_data->nu = & sndcp_data->nu_base[12];
  INIT_STATE(NU_12, NU_UNACK_SU_RECEPTIVE);

  sndcp_data->nu = & sndcp_data->nu_base[13];
  INIT_STATE(NU_13, NU_UNACK_SU_RECEPTIVE);

  sndcp_data->nu = & sndcp_data->nu_base[14];
  INIT_STATE(NU_14, NU_UNACK_SU_RECEPTIVE);

  sndcp_data->nu = & sndcp_data->nu_base[15];
  INIT_STATE(NU_15, NU_UNACK_SU_RECEPTIVE);

  for (nsapi = 0; nsapi < SNDCP_NUMBER_OF_NSAPIS; nsapi++) {
    sndcp_data->nu = & sndcp_data->nu_base[nsapi];

    sndcp_data->nu->nsapi = nsapi;
    sndcp_data->nu->send_npdu_number_unack = 0;
    sndcp_data->nu->send_npdu_number_ack = 0;
    sndcp_data->nu->rec_npdu_number_ack = 0;
    sndcp_data->nu->first_buffered_npdu = NULL;
    sndcp_data->nu->next_resend = NULL;
    sndcp_data->nu->sn_ready_ind_pending = FALSE;
    sndcp_data->nu->sn_unitready_ind_pending = FALSE;
    sndcp_data->nu->connection_is_opened = FALSE;
    sndcp_data->nu->discard = FALSE;
    sndcp_data->nu->discarded_data = 0;
    sndcp_data->nu->sent_data = 0;
  }
} /* nu_init() */


/*
+------------------------------------------------------------------------------
| Function    : nu_ready_ind_if_nec
+------------------------------------------------------------------------------
| Description : Sends an SN_READY_IND if none is pending and DTI connection is
|               opened.
|
| Parameters  : nsapi
|
+------------------------------------------------------------------------------
*/
GLOBAL void nu_ready_ind_if_nec (UBYTE nsapi)
{
  BOOL used = FALSE;
  USHORT stat = MG_IDLE;
  UBYTE sapi = 0;

  TRACE_FUNCTION( "nu_ready_ind_if_nec" );
#ifdef SNDCP_TRACE_ALL
  if (sndcp_data->nu->sn_ready_ind_pending) {
    TRACE_EVENT("sn_ready_ind_pending TRUE");
  } else {
    TRACE_EVENT("sn_ready_ind_pending FALSE");
  }
  if (sndcp_data->nu->connection_is_opened) {
    TRACE_EVENT("connection_is_opened TRUE");
  } else {
    TRACE_EVENT("connection_is_opened FALSE");
  }
#endif /* SNDCP_TRACE_ALL */

  /*
   * set service instance according to nsapi parameter
   */
  sndcp_data->nu = & sndcp_data->nu_base[nsapi];

  sndcp_get_nsapi_sapi(nsapi, &sapi);
  sndcp_get_sapi_state(sapi, &stat);
  sndcp_is_nsapi_used(nsapi, &used);

  if (! sndcp_data->nu->sn_ready_ind_pending
      &&
      sndcp_data->nu->connection_is_opened
      &&
      used
     ) {

    sndcp_data->nu->sn_ready_ind_pending = TRUE;

#ifdef SNDCP_UPM_INCLUDED    
    dti_start(sndcp_data->hDTI, 0, SNDCP_INTERFACE_UNACK, nsapi);
#else
    dti_start(sndcp_data->hDTI, 0, SNDCP_INTERFACE_ACK, nsapi);
#endif
  }

} /* nu_ready_ind_if_nec() */

/*
+------------------------------------------------------------------------------
| Function    : nu_unitready_ind_if_nec
+------------------------------------------------------------------------------
| Description : Sends an SN_UNITREADY_IND if none is pending and DTI connection
|               is opened.
|
| Parameters  : nsapi
| Pre         : The correct nu instance has to be "active".
|
+------------------------------------------------------------------------------
*/
GLOBAL void nu_unitready_ind_if_nec (UBYTE nsapi)
{
  BOOL used = FALSE;
  USHORT stat = MG_IDLE;
  UBYTE sapi = 0;

  TRACE_FUNCTION( "nu_unitready_ind_if_nec" );
#ifdef SNDCP_TRACE_ALL
  if (sndcp_data->nu->sn_unitready_ind_pending) {
    TRACE_EVENT("sn_unitready_ind_pending TRUE");
  } else {
    TRACE_EVENT("sn_unitready_ind_pending FALSE");
  }
  if (sndcp_data->nu->connection_is_opened) {
    TRACE_EVENT("connection_is_opened TRUE");
  } else {
    TRACE_EVENT("connection_is_opened FALSE");
  }
#endif

  sndcp_get_nsapi_sapi(nsapi, &sapi);
  sndcp_get_sapi_state(sapi, &stat);
  sndcp_is_nsapi_used(nsapi, &used);

  if (! sndcp_data->nu->sn_unitready_ind_pending
      &&
      sndcp_data->nu->connection_is_opened
      &&
      used
     ) {
#ifdef SNDCP_TRACE_ALL
      TRACE_EVENT("trying to palloc/send SN_UNITREADY_IND");
#endif


    sndcp_data->nu->sn_unitready_ind_pending = TRUE;

    dti_start(sndcp_data->hDTI, 0, SNDCP_INTERFACE_UNACK, nsapi);

  }
} /* nu_unitready_ind_if_nec() */