view src/g23m-fad/ppp/ppp_arbf.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 
|             procedures and functions as described in the 
|             SDL-documentation (ARB-statemachine)
+----------------------------------------------------------------------------- 
*/ 

#ifndef PPP_ARBF_C
#define PPP_ARBF_C
#endif /* !PPP_ARBF_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_lcpf.h"   /* to get function interface from lcp */
#include "ppp_papf.h"   /* to get function interface from pap */
#include "ppp_capf.h"   /* to get function interface from chap */
#include "ppp_ncpf.h"   /* to get function interface from ncp */

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

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

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

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



/*
+------------------------------------------------------------------------------
| Function    : arb_init
+------------------------------------------------------------------------------
| Description : The function arb_init() inizializes the arbitration (ARB)
|
| Parameters  : no parameters
|
+------------------------------------------------------------------------------
*/
GLOBAL void arb_init ()
{
  TRACE_FUNCTION( "arb_init" );

  /*
   * initialize protocol-reject identifier
   */
  ppp_data->arb.pri = 1;
  /*
   * initialize time out counter
   */
  ppp_data->arb.to_counter = 1;
  /*
   * initialize pointer to last sent IPCP packet
   */
  ppp_data->arb.last_ipcp = NULL;


  INIT_STATE( PPP_SERVICE_ARB , ARB_DEAD );

  /*
   *  DTI channels
   */ 

  ppp_data->arb.dti_connect_state_prot = DTI_CLOSED;
  ppp_data->arb.dti_connect_state_peer = DTI_CLOSED;
} /* arb_init() */



/*
+------------------------------------------------------------------------------
| Function    : arb_discard_packet
+------------------------------------------------------------------------------
| Description : The function arb_discard_packet() frees the memory of 
|               the given packet
|
| Parameters  : packet - pointer to a generic data descriptor
|
+------------------------------------------------------------------------------
*/
GLOBAL void arb_discard_packet (T_desc2* packet)
{ 
  T_desc2* temp_desc;
  TRACE_FUNCTION( "arb_discard_packet" );
  
  while(packet NEQ NULL)
  {
    temp_desc=(T_desc2*)packet->next;
    MFREE(packet);
    packet=temp_desc;
  }
} /* arb_discard_packet() */



/*
+------------------------------------------------------------------------------
| Function    : arb_get_protocol_reject
+------------------------------------------------------------------------------
| Description : The function arb_get_protocol_reject() creates 
|               a LCP protocol reject
|
| Parameters  : ptype      - packet type
|               packet     - packet which have to be rejected
|               ptr_packet - returns a LCP protocol reject packet
|
+------------------------------------------------------------------------------
*/
GLOBAL void arb_get_protocol_reject (USHORT ptype, 
                                     T_desc2* packet, 
                                     T_desc2** ptr_packet)
{
  USHORT    temp_len;
  T_desc2*   temp_desc;
  T_desc2*   ret_desc;

  TRACE_FUNCTION( "arb_get_protocol_reject" );

  /*
   * 1 octet code field
   * 1 octet identifier field
   * 2 octets length field
   * 2 octets rejected-protocol field
   *----------
   * 6 octets
   */
  MALLOC (ret_desc, (USHORT)(sizeof(T_desc2) - 1 + 6));
  ret_desc->next = (ULONG)packet;
  ret_desc->len  = 6;
  
  /*
   * Code field for protocol reject
   */
  ret_desc->buffer[0] = CODE_PROT_REJ;

  /*
   * Identifier field
   */
  ret_desc->buffer[1] = ppp_data->arb.pri;/*lint !e415 (Warning -- access of out-of-bounds pointer) */

  ppp_data->arb.pri++;

  /*
   * Length field
   */
  temp_len = 0;
  packet   = ret_desc;
  while(packet NEQ NULL)
  {
    temp_len+= packet->len;
    packet   = (T_desc2*)packet->next;
  }
  if(temp_len > PPP_MRU_MIN)
    temp_len=ppp_data->mru;
  ret_desc->buffer[2] = (UBYTE)(temp_len >> 8);/*lint !e415 !e416 (Warning -- access/creation of out-of-bounds pointer) */
  ret_desc->buffer[3] = (UBYTE)(temp_len & 0x00ff);/*lint !e415 !e416 (Warning -- access/creation of out-of-bounds pointer) */

  /*
   * Rejected-Protocol field
   */
  ret_desc->buffer[4] = (UBYTE)(ptype >> 8);/*lint !e415 !e416 (Warning -- access/creation of out-of-bounds pointer) */
  ret_desc->buffer[5] = (UBYTE)(ptype & 0x00ff);/*lint !e415 !e416 (Warning -- access/creation of out-of-bounds pointer) */

  /*
   * cut the rejected packet if it is to long
   */
  packet = ret_desc;
  while(temp_len > packet->len)
  {
    temp_len-= packet->len;
    packet   = (T_desc2*)packet->next;
  }
  packet->len  = temp_len;
  temp_desc    = (T_desc2*)packet->next;
  packet->next = (ULONG)NULL;
  while(temp_desc NEQ NULL)
  {
    packet = (T_desc2*)temp_desc->next;
    MFREE(temp_desc);
    temp_desc = packet;
  }
  /*
   * return created protocol reject packet
   */
  *ptr_packet = ret_desc;

  /*lint -e415 -e416 (Warning -- access/creation of out-of-bounds pointer) */
} /* arb_get_protocol_reject() */



/*
+------------------------------------------------------------------------------
| Function    : arb_get_pco_list
+------------------------------------------------------------------------------
| Description : The function arb_get_pco_list() creates the list of 
|               protocol configuratrion options as shown in 10.5.6.3/GSM 04.08
|
| Parameters  : ptr_pco_list - returns list of protocol configuration options
|
+------------------------------------------------------------------------------
*/
GLOBAL void arb_get_pco_list (T_sdu* ptr_pco_list)
{ 
  UBYTE   ap;
  USHORT  mru;
  ULONG   accm;
  UBYTE   pfc;
  UBYTE   acfc;

  TRACE_FUNCTION( "arb_get_pco_list" );

  /*
   * initialize sdu
   */
  ptr_pco_list->o_buf=0;
  ptr_pco_list->l_buf=0;
  
  /*
   * declare Configuration Protocol PPP
   */
  ptr_pco_list->buf[ptr_pco_list->l_buf]=0x80;
  ptr_pco_list->l_buf++;

  /*
   * first packets are LCP packets
   */
  lcp_fill_out_packet(ptr_pco_list->buf, &ptr_pco_list->l_buf);
  /*
   * next packets may be authentication packets
   */
  if(ppp_data->pco_mask & PPP_PCO_MASK_AUTH_PROT)
  {
    lcp_get_values(&ap, &mru, &accm, &pfc, &acfc);
    switch(ap)
    {
      case PPP_AP_PAP:
        /*
         * insert PAP authentication packet
         */
        pap_fill_out_packet(ptr_pco_list->buf, &ptr_pco_list->l_buf);
        break;
      case PPP_AP_CHAP:
        /*
         * insert CHAP authentication packets
         */
        chap_fill_out_packet(ptr_pco_list->buf, &ptr_pco_list->l_buf);
        break;
    }
  }
  /*
   * next packet is the IPCP packet received from PPP peer
   */
  ncp_fill_out_packet(ptr_pco_list->buf, &ptr_pco_list->l_buf);
  /*
   * convert length in octet to length in bit
   */
  ptr_pco_list->l_buf=ptr_pco_list->l_buf << 3;

} /* arb_get_pco_list() */



/*
+------------------------------------------------------------------------------
| Function    : arb_analyze_pco_list
+------------------------------------------------------------------------------
| Description : The function arb_analyze_pco_list() analyzes the given list of
|               protocol configuration options and returns values of interest
|
| Parameters  : pco_list    - list of protocol configuration options
|               ptr_dns1    - returns Primary DNS Server Address
|               ptr_dns2    - returns Secondary DNS Server Address
|               ptr_gateway - returns Gateway Address
|
+------------------------------------------------------------------------------
*/
GLOBAL void arb_analyze_pco_list (T_sdu*  pco_list, 
                                  ULONG*  ptr_dns1,
                                  ULONG*  ptr_dns2,
                                  ULONG*  ptr_gateway)
{ 
  USHORT  pos;

  TRACE_FUNCTION( "arb_analyze_pco_list" );
  
  /*
   * initialize return values
   */
  *ptr_dns1    = PPP_PDNS_DEFAULT;
  *ptr_dns2    = PPP_SDNS_DEFAULT;
  *ptr_gateway = PPP_GATEWAY_DEFAULT;
  
  /*
   * analyze pco list
   */
  pco_list->l_buf = pco_list->l_buf >> 3;
  pco_list->o_buf = pco_list->o_buf >> 3;
  pos             = pco_list->o_buf;
  if((pco_list->l_buf > 0) && (pco_list->buf[pos] EQ 0x80))
  {
    pos++;
    while(pos < (pco_list->l_buf + pco_list->o_buf))
    {
      if((pco_list->buf[pos]     EQ PROTOCOL_IPCP_MSB) &&
         (pco_list->buf[pos + 1] EQ PROTOCOL_IPCP_LSB))
      {
        /*
         * determine DNS addresses and Gateway address
         */
        ncp_analyze_pco (pco_list->buf, pos, ptr_dns1, ptr_dns2, ptr_gateway);
      }
      pos+= pco_list->buf[pos + 2] + 3;
    }
  }
} /* arb_analyze_pco_list() */

/*
+------------------------------------------------------------------------------
| Function    : arb_dti_close_prot_ind
+------------------------------------------------------------------------------
| Description : Close the DTI Protocol Channel
|
| Parameters  : no parameters
|
+------------------------------------------------------------------------------
*/
GLOBAL void arb_dti_close_prot_ind ()
{  
  TRACE_FUNCTION("arb_dti_close_prot_ind");
  
  switch (ppp_data->arb.dti_connect_state_prot)
  {    
    case DTI_SETUP:
    case DTI_IDLE:
      dti_close(ppp_data->ppphDTI, PPP_INSTANCE, 
                PROT_LAYER, PROT_CHANNEL, FALSE);
      ppp_data->arb.dti_connect_state_prot = DTI_CLOSED;  
      break;    
    default:
      break;
  }
} /* arb_dti_close_prot_ind */

/*
+------------------------------------------------------------------------------
| Function    : arb_dti_close_peer_ind
+------------------------------------------------------------------------------
| Description : Close the DTI Peer Channel
|
| Parameters  : no parameters
|
+------------------------------------------------------------------------------
*/
GLOBAL void arb_dti_close_peer_ind ()
{  
  TRACE_FUNCTION("arb_dti_close_peer_ind");
  
  switch (ppp_data->arb.dti_connect_state_peer)
  {    
    case DTI_SETUP:
    case DTI_IDLE:
      dti_close(ppp_data->ppphDTI, PPP_INSTANCE,
                PEER_LAYER, PEER_CHANNEL, FALSE);
      ppp_data->arb.dti_connect_state_peer = DTI_CLOSED;
      break;
    default:
      break;
  }
} /* arb_dti_close_peer_ind */