view src/g23m-fad/ppp/ppp_caps.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
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/*
+-----------------------------------------------------------------------------
|  Project :
|  Modul   :
+-----------------------------------------------------------------------------
|  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 PPP and implements all
|             functions to handles the incoming process internal signals as
|             described in the SDL-documentation (CHAP-statemachine)
+-----------------------------------------------------------------------------
*/

#ifndef PPP_CHAPS_C
#define PPP_CHAPS_C
#endif /* !PPP_CAPS_C */

#define ENTITY_PPP

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

#include "typedefs.h"   /* to get Condat data types */
#include "vsi.h"        /* to get a lot of macros */
#include "macdef.h"     /* to get a lot of macros */
#include "custom.h"     /* to get a lot of macros */
#include "gsm.h"        /* to get a lot of macros */
#include "cnf_ppp.h"    /* to get cnf-definitions */
#include "mon_ppp.h"    /* to get mon-definitions */
#include "prim.h"       /* to get the definitions of used SAP and directions */
#include "dti.h"        /* to get the DTILIB definitions */
#include "ppp.h"        /* to get the global entity definitions */

#include "ppp_capf.h"   /* to get function interface from chap */
#include "ppp_arbf.h"   /* to get function interface from arb */
#include "ppp_ftxs.h"   /* to get signal interface from ftx */
#include "ppp_arbs.h"   /* to get signal interface from arb */
#include "ppp_rts.h"    /* to get the rt signal interface */

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

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

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

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



/*
+------------------------------------------------------------------------------
| Function    : sig_arb_chap_packet_req
+------------------------------------------------------------------------------
| Description : Handles the internal signal SIG_ARB_CHAP_PACKET_REQ
|
| Parameters  : packet - pointer to a generic data descriptor
|
+------------------------------------------------------------------------------
*/
GLOBAL void sig_arb_chap_packet_req (T_desc2* packet)
{

  T_desc2* temp_desc;
  UBYTE   forward;

  TRACE_ISIG( "sig_arb_chap_packet_req" );

  /*
   * depend on the code-field call appropriate function
   */
  switch(packet->buffer[0])
  {
    case CODE_CHALLENGE:
      chap_rc(&packet, &forward);
      break;
    case CODE_RESPONSE:
      chap_rr(&packet, &forward);
      break;
    case CODE_SUCCESS:
      chap_rs(packet, &forward);
      break;
    case CODE_FAILURE:
      chap_rf(packet, &forward);
      break;
    default:
      forward = FORWARD_DISCARD;
      break;
  }
  switch(forward)
  {
    case FORWARD_RC:  /* Received Challenge */
      /*
       * send Response packet and wait for an appropriate answer
       */
      SET_STATE( PPP_SERVICE_CHAP, CHAP_UP );
      ppp_data->chap.counter = ppp_data->mc;
      sig_any_ftx_packet_req(DTI_PID_CHAP, packet); /* Response */
      if(ppp_data->chap.counter > 0)
        ppp_data->chap.counter--;
      sig_any_rt_rrt_req();
      break;
    case FORWARD_RRP:  /* Received Response Positive */
      /*
       * send Success packets until receive a stop signal from arb
       * or the counter becomes zero
       */
      SET_STATE( PPP_SERVICE_CHAP, CHAP_UP );
      ppp_data->chap.counter = ppp_data->mc;
      sig_any_ftx_packet_req(DTI_PID_CHAP, packet); /* Success */
      if(ppp_data->chap.counter > 0)
        ppp_data->chap.counter--;
      sig_any_rt_rrt_req();
      sig_any_arb_tlu_ind();
      break;
    case FORWARD_RRN:  /* Received Response Negative  */
      /*
       * send Failure packet
       */
      sig_any_ftx_packet_req(DTI_PID_CHAP, packet); /* Failure */
      if(ppp_data->chap.fails > 0)
      {
        /*
         * if failure counter is not zero then create a new Challenge packet
         */
        ppp_data->chap.fails--;
        ppp_data->chap.counter = ppp_data->mc;
        chap_get_sc(&temp_desc);
        sig_any_ftx_packet_req(DTI_PID_CHAP, temp_desc); /* Challenge */
        if(ppp_data->chap.counter > 0)
          ppp_data->chap.counter--;
        sig_any_rt_rrt_req();
      }
      else
      {
        /*
         * if failure counter expired then set error code
         */
        sig_any_rt_srt_req();
        if(ppp_data->ppp_cause EQ 0)
          ppp_data->ppp_cause = PPP_TERM_USE_AUTHED_FAILED;
        sig_any_arb_tlf_ind();
      }
      break;
    case FORWARD_RS:  /* Received Success */
      sig_any_rt_srt_req();
      sig_any_arb_tlu_ind();
      break;
    case FORWARD_RF:  /* Received Failure */
      /*
       * restart timer and wait for new challenge packet
       */
      SET_STATE( PPP_SERVICE_CHAP, CHAP_DOWN );
      ppp_data->chap.counter = ppp_data->mc;
      if(ppp_data->chap.counter > 0)
        ppp_data->chap.counter--;
      sig_any_rt_rrt_req();
      break;
    default:
      arb_discard_packet(packet);
      break;
  }
} /* sig_arb_chap_packet_req() */



/*
+------------------------------------------------------------------------------
| Function    : sig_arb_chap_open_req
+------------------------------------------------------------------------------
| Description : Handles the internal signal SIG_ARB_CHAP_OPEN_REQ
|
| Parameters  : no parameters
|
+------------------------------------------------------------------------------
*/
GLOBAL void sig_arb_chap_open_req ()
{
  T_desc2* packet;

  TRACE_ISIG( "sig_arb_chap_open_req" );

  SET_STATE( PPP_SERVICE_CHAP, CHAP_DOWN );
  ppp_data->chap.sc      = FALSE;
  ppp_data->chap.counter = ppp_data->mc;
  ppp_data->chap.fails   = ppp_data->mf;

  if(ppp_data->mode EQ PPP_SERVER)
  {
    /*
     * create and send challenge packet
     */
    chap_get_sc(&packet);
    sig_any_ftx_packet_req(DTI_PID_CHAP, packet); /* Challenge */
  }

  /*
   * start timer (client and server)
   */
  if(ppp_data->chap.counter > 0)
    ppp_data->chap.counter--;
  sig_any_rt_rrt_req();
} /* sig_arb_chap_open_req() */



/*
+------------------------------------------------------------------------------
| Function    : sig_arb_chap_down_req
+------------------------------------------------------------------------------
| Description : Handles the internal signal SIG_ARB_CHAP_DOWN_REQ
|
| Parameters  : no parameters
|
+------------------------------------------------------------------------------
*/
GLOBAL void sig_arb_chap_down_req ()
{
  TRACE_ISIG( "sig_arb_chap_down_req" );

  sig_any_rt_srt_req();
  arb_discard_packet(ppp_data->chap.c_packet);
  ppp_data->chap.c_packet = NULL;
  arb_discard_packet(ppp_data->chap.r_packet);
  ppp_data->chap.r_packet = NULL;
} /* sig_arb_chap_down_req() */



/*
+------------------------------------------------------------------------------
| Function    : sig_arb_chap_stop_req
+------------------------------------------------------------------------------
| Description : Handles the internal signal SIG_ARB_CHAP_STOP_REQ
|
| Parameters  : no parameters
|
+------------------------------------------------------------------------------
*/
GLOBAL void sig_arb_chap_stop_req ()
{
  TRACE_ISIG( "sig_arb_chap_stop_req" );

  sig_any_rt_srt_req();
} /* sig_arb_chap_down_req() */



/*
+------------------------------------------------------------------------------
| Function    : sig_arb_chap_to_req
+------------------------------------------------------------------------------
| Description : Handles the internal signal SIG_ARB_CHAP_TO_REQ
|
| Parameters  : no parameters
|
+------------------------------------------------------------------------------
*/
GLOBAL void sig_arb_chap_to_req ()
{
  T_desc2* packet = NULL;

  TRACE_ISIG( "sig_arb_chap_to_req" );

  if (ppp_data->chap.counter EQ 0)
  {
    /*
     * authentication failed (client and server mode)
     */
    if((ppp_data->ppp_cause EQ 0) && (ppp_data->mode EQ PPP_CLIENT))
      ppp_data->ppp_cause = PPP_TERM_NO_RESPONSE;
    sig_any_arb_tlf_ind();
  }
  else
  {
    if(ppp_data->mode EQ PPP_SERVER)
    {
      switch( GET_STATE( PPP_SERVICE_CHAP ) )
      {
        case CHAP_UP:
          /*
           * create Success packet
           */
          chap_get_ss(&packet);
          break;
        case CHAP_DOWN:
          /*
           * create Challenge packet
           */
          chap_get_sc(&packet);
          break;
        default:
          TRACE_EVENT("WARNING: unexpected chap time out request in server mode");
          break;
      }
      /*
       * send packet
       */
      sig_any_ftx_packet_req(DTI_PID_CHAP, packet);
    }
    else if(ppp_data->mode EQ PPP_CLIENT)
    {
      switch( GET_STATE( PPP_SERVICE_CHAP ) )
      {
        case CHAP_UP:
          if(ppp_data->chap.sr)
          {
            /*
             * Retransmit Response packet.
             */
            packet = ppp_data->chap.c_packet;
            chap_get_sr(&packet);
            /*
             * Send Response packet.
             */
            sig_any_ftx_packet_req(DTI_PID_CHAP, packet);
          } else {
            TRACE_EVENT("WARNING: CHAP_UP state, but no Response transmitted");
          }
          break;
        case CHAP_DOWN:
          /*
           * Wait for CHAP Challenge,
           * GET_DATA_REQ will be sent after time out by FTX service.
           */
          break;
        default:
          TRACE_EVENT("WARNING: unexpected chap time out request in client mode");
          break;
      }
    } else {
      TRACE_EVENT_P1("ERROR: undefined PPP mode - chap_caps.c (%d)", __LINE__);
    }
    /*
     * restart timer
     */
    ppp_data->chap.counter--;
    sig_any_rt_rrt_req();
  }
} /* sig_arb_chap_to_req() */