Source code of Windows XP (NT5)
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/***************************************************************************
Name : FRAMING.C
Comment :
Functions: (see Prototypes just below)
Copyright (c) Microsoft Corp. 1991 1992 1993
Revision Log
Date Name Description
-------- ----- ---------------------------------------------------------
***************************************************************************/
#include "prep.h"
#include "encoder.h"
#include "decoder.h"
#include "class1.h"
#include "debug.h"
#include "glbproto.h"
#define faxTlog(m) DEBUGMSG(ZONE_SWFRAME, m)
#define faxT2log(m) DEBUGMSG(ZONE_SWFRAME2, m)
#define FILEID FILEID_FRAMING
#ifdef DEBUG
# define ST_SWFRAME2(x) if(ZONE_SWFRAME2) { x; }
#else
# define ST_SWFRAME2(x) { }
#endif
BOOL FramingBufSetup(PThrdGlbl pTG, BOOL fOn);
BOOL SWFramingSendSetup(PThrdGlbl pTG, BOOL fOn)
{
// If fOn=TRUE, Check that Recv framing is not ON.
// Can't use Recv and Send framing simultaneously
BG_CHK(!(fOn && pTG->Class1Modem.fRecvSWFraming));
if(fOn)
{
BG_CHK(!pTG->Class1Modem.fSendSWFraming);
}
else if(!pTG->Class1Modem.fSendSWFraming)
{
TRACE((SZMOD "<<WARNING>> SWFramingSendSetup(FALSE) called when not inited. Ignoring\r\n"));
return TRUE;
}
if(!FramingBufSetup(pTG, fOn))
return FALSE;
pTG->Class1Modem.fSendSWFraming = fOn;
InitEncoder(pTG, pTG->Framing.EncodeState);
return TRUE;
}
BOOL SWFramingRecvSetup(PThrdGlbl pTG, BOOL fOn)
{
// if fOn=TRUE Check that Send framing is not ON.
// Can't use Recv and Send framing simultaneously
BG_CHK(!(fOn && pTG->Class1Modem.fSendSWFraming));
if(fOn)
{
BG_CHK(!pTG->Class1Modem.fRecvSWFraming);
}
else if(!pTG->Class1Modem.fRecvSWFraming)
{
TRACE((SZMOD "<<WARNING>> SWFramingRecvSetup(FALSE) called when not inited. Ignoring\r\n"));
return TRUE;
}
if(!FramingBufSetup(pTG, fOn))
return FALSE;
pTG->Class1Modem.fRecvSWFraming = fOn;
InitDecoder(pTG, pTG->Framing.DecodeState);
return TRUE;
}
BOOL FramingBufSetup(PThrdGlbl pTG, BOOL fOn)
{
// UWORD uwJunk;
if(fOn)
{
#ifdef SMM
pTG->Framing.lpbBuf = pTG->bStaticFramingBuf;
pTG->Framing.cbBufSize = FRAMEBUFINITIALSIZE;
#else
#error NYI ERROR: Code Not Complete--Have to pick GMEM_ flags (FIXED? SHARE?)
...also have to call IFProcSetResFlags(hinstMe).....
BG_CHK(pTG->Framing.lpbBuf==0);
if(!(pTG->Framing.lpbBuf = IFMemAlloc(0, FRAMEBUFINITIALSIZE, &uwJunk)))
{
ERRMSG((SZMOD "<<ERROR>> Out of global memory!!));
// iModemSetError(MODEMERR_RESOURCES, ERR_OUT_OF_MEMORY, 0);
return FALSE;
}
pTG->Framing.cbBufSize = uwJunk;
#endif
}
else
{
BG_CHK(fOn == FALSE);
#ifndef SMM
BG_CHK(pTG->Framing.lpbBuf);
IFMemFree(pTG->Framing.lpbBuf);
#endif
pTG->Framing.lpbBuf = 0;
pTG->Framing.cbBufSize = 0;
}
pTG->Framing.cbBufCount = 0;
pTG->Framing.lpbBufSrc = pTG->Framing.lpbBuf;
pTG->Framing.swEOF = 0;
return TRUE;
}
BOOL SWFramingSendFrame(PThrdGlbl pTG, LPBYTE lpb, USHORT uCount, USHORT uFlags)
{
WORD wCRC;
USHORT cbDst;
(MyDebugPrint(pTG, LOG_ALL, "iSW: lpb=%08lx c=%d f=%02x ", lpb, uCount, uFlags, lpb[0]));
// always DLE-stuff here. Never zero-stuff
BG_CHK(uFlags & SEND_ENDFRAME);
BG_CHK(lpb && uCount);
BG_CHK(uCount <= 260); // can add stuff to realloc the Dst buffer
// to a bigger one as needed here
wCRC = CalcCRC(pTG, lpb, uCount);
faxT2log((SZMOD "CRC=%04x ", wCRC));
cbDst = HDLC_Encode(pTG, lpb, uCount, pTG->Framing.lpbBuf, &pTG->Framing.EncodeState);
faxT2log((SZMOD "D1=%d ", cbDst));
cbDst += HDLC_Encode(pTG, (LPB)(&wCRC), 2, pTG->Framing.lpbBuf+cbDst, &pTG->Framing.EncodeState);
faxT2log((SZMOD "D2=%d\r\n", cbDst));
BG_CHK(cbDst + pTG->ModemParams.InterframeFlags <= pTG->Framing.cbBufSize);
cbDst += HDLC_AddFlags(pTG, pTG->Framing.lpbBuf+cbDst, pTG->ModemParams.InterframeFlags, &pTG->Framing.EncodeState);
faxT2log((SZMOD "D3=%d f=%02x l=%02x\r\n", cbDst, pTG->Framing.lpbBuf[0], pTG->Framing.lpbBuf[cbDst-1]));
// always DLE-stuff here. Never zero-stuff
if(!FComFilterAsyncWrite(pTG, pTG->Framing.lpbBuf, cbDst, FILTER_DLEONLY))
{
ERRMSG((SZMOD "<<ERROR>> DataWrite Timeout\r\n"));
goto error;
}
if(uFlags & SEND_FINAL)
{
if(!SWFramingSendPostamble(pTG, pTG->Class1Modem.CurMod))
goto error;
#ifdef CL0
if(pTG->ModemParams.Class == FAXCLASS0)
{
if(!FComDirectAsyncWrite(pTG, bDLEETXOK, 8))
goto error;
}
else
#endif //CL0
{
// if(!FComDirectAsyncWrite(bDLEETXCR, 3))
if(!FComDirectAsyncWrite(pTG, bDLEETX, 2))
goto error;
}
if(!iModemDrain(pTG))
goto error;
SWFramingSendSetup(pTG, FALSE);
FComOutFilterClose(pTG);
FComOverlappedIO(pTG, FALSE);
FComXon(pTG, FALSE); // critical. End of PhaseC
EndMode(pTG);
}
return TRUE;
error:
SWFramingSendSetup(pTG, FALSE);
FComOutFilterClose(pTG);
FComOverlappedIO(pTG, FALSE);
FComXon(pTG, FALSE); // critical. End of PhaseC (err)
EndMode(pTG);
return FALSE;
}
BOOL SWFramingSendFlags(PThrdGlbl pTG, USHORT uHowMany)
{
int cb, i; // must be signed
(MyDebugPrint(pTG, LOG_ALL, "SENDING ECM Flags (%d).....\r\n", uHowMany));
for(i=0, cb = uHowMany; cb>0; i++, cb -= pTG->Framing.cbBufSize)
{
if(i<=1)
HDLC_AddFlags(pTG, pTG->Framing.lpbBuf, pTG->Framing.cbBufSize, &pTG->Framing.EncodeState);
// always DLE-stuff here. Never zero-stuff
if(!FComFilterAsyncWrite(pTG, pTG->Framing.lpbBuf,(USHORT) min((USHORT)pTG->Framing.cbBufSize, (USHORT)cb), FILTER_DLEONLY))
{
ERRMSG((SZMOD "<<ERROR>> PreFlagDataWrite Timeout\r\n"));
return FALSE;
}
}
return TRUE;
}
USHORT SWFramingRecvFrame(PThrdGlbl pTG, LPBYTE lpb, USHORT cbMax, ULONG ulTimeout, USHORT far* lpcbRecv)
{
USHORT cbDst, cbProduce, cbConsume, uRet;
LPB lpbDst;
(MyDebugPrint(pTG, LOG_ALL, "iSW: Buf=%08lx Src=%08lx cbSrc=%d cbMax=%d\r\n", pTG->Framing.lpbBuf, pTG->Framing.lpbBufSrc, pTG->Framing.cbBufCount, cbMax));
/**/
BG_CHK(pTG->Class1Modem.ModemMode == FRM);
BG_CHK(pTG->Class1Modem.fRecvSWFraming);
startTimeOut(pTG, &(pTG->Class1Modem.toRecv), ulTimeout);
/**/
BG_CHK(lpb && cbMax && lpcbRecv);
*lpcbRecv = 0;
for(lpbDst=lpb, cbDst=cbMax ;; )
{
if(pTG->Framing.cbBufCount == 0)
{
if(pTG->Framing.swEOF == 0)
{
pTG->Framing.lpbBufSrc = pTG->Framing.lpbBuf;
// 4th arg must be FALSE for Class1
pTG->Framing.cbBufCount = FComFilterReadBuf(pTG, pTG->Framing.lpbBufSrc, pTG->Framing.cbBufSize, &(pTG->Class1Modem.toRecv), FALSE, &pTG->Framing.swEOF);
faxT2log((SZMOD "f=%02x l=%02x\r\n", pTG->Framing.lpbBufSrc[0], pTG->Framing.lpbBufSrc[pTG->Framing.cbBufCount-1]));
if(pTG->Framing.swEOF == -1)
{
#ifdef CL0
if(pTG->ModemParams.Class == FAXCLASS0)
{
TRACE((SZMOD "Got Class0 DLE-ETX\r\n"));
pTG->Framing.swEOF = 1;
}
else
#endif //CL0
{
// See LONG comment under DDI.C ModemRecvData()
// option (a)
// ERRMSG((SZMOD "<<WARNING>> Got arbitrary DLE-ETX. Assuming END OF PAGE!!!\r\n"));
// pTG->Framing.swEOF = 1;
// option (b)
ERRMSG((SZMOD "<<WARNING>> Got arbitrary DLE-ETX. Ignoring\r\n"));
pTG->Framing.swEOF = 0;
}
}
BG_CHK(pTG->Framing.swEOF == 0 || pTG->Framing.swEOF == 1 ||
pTG->Framing.swEOF == -2 || pTG->Framing.swEOF == -3);
// check for progress
BG_CHK(pTG->Framing.cbBufCount!=0 || pTG->Framing.swEOF!=0);
}
else
{
// pTG->Framing.swEOF != 0
BG_CHK(pTG->Framing.swEOF == 1 || pTG->Framing.swEOF == -2 || pTG->Framing.swEOF == -3);
if(cbDst != cbMax)
{
ERRMSG((SZMOD "<<WARNING>> SWFramingRecv: Got EOF with partial frame %d bytes\r\n", cbMax-cbDst));
ST_SWFRAME2(D_HexPrint(lpb, (USHORT)(cbMax-cbDst)));
uRet = RECV_BADFRAME;
goto done;
}
if(pTG->Framing.swEOF == 1) // class1 eof
{
SWFramingRecvSetup(pTG, FALSE);
EndMode(pTG);
uRet = RECV_EOF;
goto done;
}
else if(pTG->Framing.swEOF < 0) // error or timeout
{
SWFramingRecvSetup(pTG, FALSE);
EndMode(pTG);
uRet = ((pTG->Framing.swEOF == -2) ? RECV_ERROR : RECV_TIMEOUT);
goto done;
}
}
}
// cbDst=space left in destination lpbDst=start of space
// pTG->Framing.cbBufCount=bytes left in source pTG->Framing.lpbBufSrc=start of bytes
cbConsume = HDLC_Decode(pTG, pTG->Framing.lpbBufSrc,(USHORT) min(pTG->Framing.cbBufCount, cbDst), lpbDst, &cbProduce, &pTG->Framing.DecodeState);
BG_CHK(cbConsume <= pTG->Framing.cbBufCount && pTG->Framing.lpbBufSrc+cbConsume<=pTG->Framing.lpbBuf+pTG->Framing.cbBufSize);
BG_CHK(cbProduce <= cbDst && lpbDst+cbProduce <= lpb+cbMax);
faxT2log((SZMOD "iSW: C=%d P=%d fa=%d\r\n", cbConsume, cbProduce, pTG->Framing.DecodeState.flagabort));
pTG->Framing.cbBufCount -= cbConsume;
pTG->Framing.lpbBufSrc += cbConsume;
cbDst -= cbProduce;
lpbDst += cbProduce;
// check for progress.
BG_CHK(pTG->Framing.DecodeState.flagabort==FLAG || // exits below
cbProduce || cbConsume || // exits eventually
pTG->Framing.cbBufCount==0); // exits or continues above
if(pTG->Framing.DecodeState.flagabort == FLAG)
{
if((cbMax-cbDst)>=2 && (CalcCRC(pTG, lpb, (USHORT)(cbMax-cbDst)) == ((WORD)(~0xF0B8))) )
{
cbDst += 2;
if(cbMax <= cbDst)
{
ERRMSG(("GOOD Frame BAD Length!! cbMax=%d cbDst=%d, lpb[0]=%02x lpb[1]=%02x, CRC=%04x\r\n",
cbMax, cbDst, lpb[0], lpb[1], CalcCRC(pTG, lpb, (USHORT)(cbMax+2-cbDst))));
BG_CHK(FALSE); // can't get good frame of 0 length!
// must return RECV_BADFRAME here otherwise we break.
// In HDLC.C the (RECV_OK swRead==0) pair gets converted
// to RECV_ERROR and we quit receiving. On some modems
// this can happen often. See BUG#1684
uRet = RECV_BADFRAME;
}
else
uRet = RECV_OK;
}
else
{
BG_CHK(cbMax >= cbDst);
#ifdef DEBUG
if (cbMax-cbDst)
{
ERRMSG((SZMOD "<<WARNING>> BADFR: SWFrRecvFr: CbMax-cbDst = %d bytes\r\n", cbMax-cbDst));
}
#endif
ST_SWFRAME2(D_HexPrint(lpb, (USHORT)(cbMax-cbDst)));
uRet = RECV_BADFRAME;
}
goto done;
}
else if(pTG->Framing.DecodeState.flagabort == ABORT)
{
lpbDst=lpb; cbDst=cbMax;
}
else if(cbDst == 0)
{
// bad frames can be very long
ERRMSG((SZMOD "<<WARNING>> SWFramingRecv: Overflow. Got %d chars -- no flag\r\n", cbMax));
uRet = RECV_BADFRAME;
goto done;
}
}
done:
*lpcbRecv = cbMax-cbDst;
(MyDebugPrint(pTG, LOG_ALL, "xSW: uR=%d *lpcbR=%d\r\n", uRet, *lpcbRecv));
return uRet;
}
/*********************
ECM Preamble and PostAmble: In T.4 appendix A it says
that the Preamble must be 200ms +/1 100ms of flags,
and the postamble must be 50ms max.
However we also have recving modems that don't know they
are getting ECM and need the 6eols to tell them when to
stop recving. Also some of them lose large chunks of data
at the end of PhaseC due to "carrier squelch", i.e. whne
they lose carrier, they throw away the contents of their
recv buffer.
To get 240ms of flags, just multiply CurMod by 3
// #define SWFramingSendPreamble(b) \
// (FComDirectAsyncWrite(b00EOL, 2), SWFramingSendFlags(b + b + b))
Postamble must have *max* 50ms of flags, so let's say 30ms, which is
9 flags at 2400 and 54 at 14400. Just multiply CurMod by (3/8)
to get correct number of flags
// #define SWFramingSendPostamble(b) SWFramingSendFlags((b+b+b) >> 3)
but with carrier squelch and all that, so few may not be safe.
Murata sends out 44 flags at 2400 baud on closing. So lets
just send out 80ms (just CurMod flags)
This is the 80ms postamble
// #define SWFramingSendPostamble(b) SWFramingSendFlags(b)
// Fix for DSI bug -- drops last 500 bytes or so ////
// #define SWFramingSendPostamble(b) SWFramingSendFlags(600)
*********************/
BYTE b00EOL[3] = { 0x00, 0x80, 0 };
BYTE b6EOLs[10] = { 0x00, 0x08, 0x80, 0x00, 0x08, 0x80, 0x00, 0x08, 0x80, 0x00 };
BOOL SWFramingSendPreamble(PThrdGlbl pTG, USHORT uCurMod)
{
BOOL fRet = TRUE;
#ifdef CL0
if(pTG->ModemParams.Class != FAXCLASS0)
#endif //CL0
{
// fix bug#1762. DataRace modem misses leading EOL unless
// preceded by some zeros, and it then chews up all data
// until an EOL, thereby eating up part of the first frame
SendZeros1(pTG, 100);
fRet = fRet && FComDirectAsyncWrite(pTG, b00EOL, 2);
}
fRet = fRet && SWFramingSendFlags(pTG, (USHORT)(uCurMod + uCurMod + uCurMod));
return fRet;
}
BOOL SWFramingSendPostamble(PThrdGlbl pTG, USHORT uCurMod)
{
BYTE bZero[50];
USHORT i;
BOOL fRet = TRUE;
// send 80ms of flags
fRet &= SWFramingSendFlags(pTG, uCurMod);
#ifdef CL0
if(pTG->ModemParams.Class != FAXCLASS0)
#endif //CL0
{
// then send 6EOLs
fRet &= FComDirectAsyncWrite(pTG, b6EOLs, 9);
// then send 250 or so 00s
_fmemset(bZero, 0, 50);
for (i=0; i<5; i++)
fRet &= FComDirectAsyncWrite(pTG, bZero, 50);
}
return fRet;
}