windows-server-2003/net/rras/ras/ppp/engine/callback.c

/********************************************************************/
/**               Copyright(c) 1989 Microsoft Corporation.         **/
/********************************************************************/

//***
//
// Filename:    callback.c
//
// Description: Contains FSM code to handle and callback control protocol
//
// History:
//      April 11,1993.  NarenG          Created original version.
//

#include <nt.h>
#include <ntrtl.h>
#include <nturtl.h>     // needed for winbase.h

#include <windows.h>    // Win32 base API's
#include <stdlib.h>
#include <string.h>
#include <wchar.h>

#include <lmcons.h>
#include <raserror.h>
#include <rasman.h>
#include <rasppp.h>
#include <pppcp.h>
#include <ppp.h>
#include <auth.h>
#include <callback.h>
#include <smevents.h>
#include <smaction.h>
#include <lcp.h>
#include <timer.h>
#include <rtutils.h>
#include <util.h>
#include <worker.h>

//**
//
// Call:        CbStart
//
// Returns:     none
//
// Description: Called to initiatialze the callback control protocol and to
//              initiate to callback negotiation.
//
VOID
CbStart( 
    IN PCB * pPcb,
    IN DWORD CpIndex
)
{
    DWORD        dwRetCode;
    PPPCB_INPUT  PppCbInput;
    CPCB *       pCpCb = GetPointerToCPCB( pPcb, CpIndex );

    if ( NULL == pCpCb )
    {
        return;
    }
  
    PppCbInput.fServer             = pPcb->fFlags & PCBFLAG_IS_SERVER;
    PppCbInput.bfCallbackPrivilege = (BYTE)(pPcb->fCallbackPrivilege);
    PppCbInput.CallbackDelay       = ( pPcb->ConfigInfo.dwConfigMask & 
                                     PPPCFG_UseCallbackDelay )
                                     ? pPcb->ConfigInfo.dwCallbackDelay
                                     : PppConfigInfo.dwCallbackDelay;

    PppCbInput.pszCallbackNumber   = pPcb->szCallbackNumber;

    PppLog( 2, "CallbackPriv in CB = %x", PppCbInput.bfCallbackPrivilege );
    
    dwRetCode = (CpTable[CpIndex].CpInfo.RasCpBegin)(&(pCpCb->pWorkBuf),
                    &PppCbInput);

    if ( dwRetCode != NO_ERROR )
    {
        pPcb->LcpCb.dwError = dwRetCode;

        NotifyCallerOfFailure( pPcb, dwRetCode );

        return;
    }

    pCpCb->LastId = (DWORD)-1;
    InitRestartCounters( pPcb, pCpCb );

    CbWork( pPcb, CpIndex, NULL, NULL );
}

//**
//
// Call:        CbStop
//
// Returns:     none
//
// Description: Called to stop the callback control protocol machine.
//
VOID
CbStop( 
    IN PCB * pPcb,
    IN DWORD CpIndex
)
{
    CPCB * pCpCb = GetPointerToCPCB( pPcb, CpIndex );

    if ( NULL == pCpCb )
    {
        return;
    }

    if ( pCpCb->LastId != (DWORD)-1 )
    {
        RemoveFromTimerQ(       
                      pPcb->dwPortId,
                      pCpCb->LastId, 
                      CpTable[CpIndex].CpInfo.Protocol,
                      FALSE,  
                      TIMER_EVENT_TIMEOUT );
    }

    if ( pCpCb->pWorkBuf != NULL )
    {
        (CpTable[CpIndex].CpInfo.RasCpEnd)( pCpCb->pWorkBuf );

        pCpCb->pWorkBuf = NULL;
    }
}

//**
//
// Call:        CbWork
//
// Returns:     none
//
// Description: Called when and callback control protocol packet was received or
//              a timeout ocurred or to initiate callback negotiation.
//
VOID
CbWork(
    IN PCB *         pPcb,
    IN DWORD         CpIndex,
    IN PPP_CONFIG *  pRecvConfig,
    IN PPPCB_INPUT * pCbInput
)
{
    DWORD        dwRetCode;
    CPCB *       pCpCb       = GetPointerToCPCB( pPcb, CpIndex );
    PPP_CONFIG * pSendConfig = (PPP_CONFIG*)(pPcb->pSendBuf->Information);
    PPPCB_RESULT CbResult;
    DWORD        dwLength;

    if ( NULL == pCpCb )
    {
        return;
    }

    PPP_ASSERT( NULL != pCpCb->pWorkBuf );

    dwRetCode = (CpTable[CpIndex].CpInfo.RasApMakeMessage)(
                        pCpCb->pWorkBuf,
                        pRecvConfig,
                        pSendConfig,
                        LCP_DEFAULT_MRU 
                        - PPP_PACKET_HDR_LEN,
                        (PPPAP_RESULT*)&CbResult,
                        (PPPAP_INPUT*)pCbInput );

    if ( dwRetCode != NO_ERROR )
    {
        if ( dwRetCode == ERROR_PPP_INVALID_PACKET )
        {
            PppLog(1,
                   "Silently discarding invalid callback packet on port %d",
                   pPcb->hPort );

            return;
        }
        else
        {
            pPcb->LcpCb.dwError = dwRetCode;

            NotifyCallerOfFailure( pPcb, dwRetCode );

            return;
        }
    }

    switch( CbResult.Action )
    {

    case APA_Send:
    case APA_SendWithTimeout:
    case APA_SendWithTimeout2:
    case APA_SendAndDone:

        HostToWireFormat16( (WORD)CpTable[CpIndex].CpInfo.Protocol, 
                            (PBYTE)(pPcb->pSendBuf->Protocol) );

        dwLength = WireToHostFormat16( pSendConfig->Length );

        LogPPPPacket(FALSE,pPcb,pPcb->pSendBuf,dwLength+PPP_PACKET_HDR_LEN);

        if ( ( dwRetCode = PortSendOrDisconnect( pPcb,
                                        (dwLength + PPP_PACKET_HDR_LEN)))
                                            != NO_ERROR )
        {
            return;
        }

        pCpCb->LastId = (DWORD)-1;

        if ( ( CbResult.Action == APA_SendWithTimeout ) ||
             ( CbResult.Action == APA_SendWithTimeout2 ) )
        {
            pCpCb->LastId = CbResult.bIdExpected;

            InsertInTimerQ( pPcb->dwPortId,
                            pPcb->hPort, 
                            pCpCb->LastId, 
                            CpTable[CpIndex].CpInfo.Protocol,
                            FALSE,
                            TIMER_EVENT_TIMEOUT,
                            pPcb->RestartTimer );

            //
            // For SendWithTimeout2 we increment the ConfigRetryCount. This 
            // means send with infinite retry count
            //

            if ( CbResult.Action == APA_SendWithTimeout2 ) 
            {
                (pCpCb->ConfigRetryCount)++;
            }
        }

        if ( CbResult.Action != APA_SendAndDone )
            break;

    case APA_Done:

        if ( CbResult.bfCallbackPrivilege == RASPRIV_NoCallback )
        {
            //
            // If no callback was negotiated we continue on to the next
            // phase.
            //

            FsmThisLayerUp( pPcb, CpIndex );
        }
        else
        {
            if ( pPcb->fFlags & PCBFLAG_IS_SERVER )
            {
                //
                // If we are the server side we save the callback info
                //

                strcpy( pPcb->szCallbackNumber, CbResult.szCallbackNumber );

                pPcb->ConfigInfo.dwCallbackDelay = CbResult.CallbackDelay;

            }
            else
            {
                //
                // We are the client side so, we tell the server that we 
                // bringing the link down and we tell the client to 
                // prepare for callback
                //

                FsmClose( pPcb, LCP_INDEX );
            }

            pPcb->fFlags |= PCBFLAG_DOING_CALLBACK;
        }

        break;

    case APA_NoAction:

        //
        // If we are on the client then we need to get the callback number 
        // from the user.
        //

     
        if ( ( !(pPcb->fFlags & PCBFLAG_IS_SERVER) && 
             ( CbResult.fGetCallbackNumberFromUser ) ) ) 
        {
            NotifyCaller( pPcb, PPPMSG_CallbackRequest, NULL );
        }

        break;

    default:

        break;
    }

}