Check that we have statfs before using it.

[wine.git] / dlls / user / comm16.c

/*
 * DEC 93 Erik Bos <erik@xs4all.nl>
 *
 * Copyright 1996 Marcus Meissner
 *
 * Copyright 2001 Mike McCormack
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * History:
 *
 * Mar 31, 1999. Ove Kåven <ovek@arcticnet.no>
 * - Implemented buffers and EnableCommNotification.
 *
 * Apr 3, 1999.  Lawson Whitney <lawson_whitney@juno.com>
 * - Fixed the modem control part of EscapeCommFunction16.
 *
 * Mar 3, 1999. Ove Kåven <ovek@arcticnet.no>
 * - Use port indices instead of unixfds for win16
 * - Moved things around (separated win16 and win32 routines)
 * - Added some hints on how to implement buffers and EnableCommNotification.
 *
 * May 26, 1997.  Fixes and comments by Rick Richardson <rick@dgii.com> [RER]
 * - ptr->fd wasn't getting cleared on close.
 * - GetCommEventMask() and GetCommError() didn't do much of anything.
 *   IMHO, they are still wrong, but they at least implement the RXCHAR
 *   event and return I/O queue sizes, which makes the app I'm interested
 *   in (analog devices EZKIT DSP development system) work.
 *
 * August 12, 1997.  Take a bash at SetCommEventMask - Lawson Whitney
 *                                     <lawson_whitney@juno.com>
 * July 6, 1998. Fixes and comments by Valentijn Sessink
 *                                     <vsessink@ic.uva.nl> [V]
 * Oktober 98, Rein Klazes [RHK]
 * A program that wants to monitor the modem status line (RLSD/DCD) may
 * poll the modem status register in the commMask structure. I update the bit
 * in GetCommError, waiting for an implementation of communication events.
 *
 */

#include "config.h"

#include <stdlib.h>
#include <stdarg.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <ctype.h>

#include "ntstatus.h"
#include "windef.h"
#include "winbase.h"
#include "wingdi.h"
#include "winreg.h"
#include "winuser.h"
#include "wine/winuser16.h"
#include "wine/port.h"
#include "win.h"
#include "winerror.h"

#include "wine/debug.h"

WINE_DEFAULT_DEBUG_CHANNEL(comm);

/* window's semi documented modem status register */
#define COMM_MSR_OFFSET  35
#define MSR_CTS  0x10
#define MSR_DSR  0x20
#define MSR_RI   0x40
#define MSR_RLSD 0x80
#define MSR_MASK (MSR_CTS|MSR_DSR|MSR_RI|MSR_RLSD)

#define FLAG_LPT 0x80

#define MAX_PORTS   9

struct DosDeviceStruct {
    HANDLE handle;
    int suspended;
    int unget,xmit;
    int evtchar;
    /* events */
    int commerror, eventmask;
    /* buffers */
    char *inbuf,*outbuf;
    unsigned ibuf_size,ibuf_head,ibuf_tail;
    unsigned obuf_size,obuf_head,obuf_tail;
    /* notifications */
    HWND wnd;
    int n_read, n_write;
    OVERLAPPED read_ov, write_ov;
    /* save terminal states */
    DCB16 dcb;
    /* pointer to unknown(==undocumented) comm structure */
    SEGPTR seg_unknown;
    BYTE unknown[40];
};

static struct DosDeviceStruct COM[MAX_PORTS];
static struct DosDeviceStruct LPT[MAX_PORTS];

/* update window's semi documented modem status register */
/* see knowledge base Q101417 */
static void COMM_MSRUpdate( HANDLE handle, UCHAR * pMsr )
{
    UCHAR tmpmsr=0;
    DWORD mstat=0;

    if(!GetCommModemStatus(handle,&mstat))
        return;

    if(mstat & MS_CTS_ON) tmpmsr |= MSR_CTS;
    if(mstat & MS_DSR_ON) tmpmsr |= MSR_DSR;
    if(mstat & MS_RING_ON) tmpmsr |= MSR_RI;
    if(mstat & MS_RLSD_ON) tmpmsr |= MSR_RLSD;
    *pMsr = (*pMsr & ~MSR_MASK) | tmpmsr;
}

static BOOL get_com_device_name( int port, char *devicename, DWORD size, int *baudrate )
{
    HKEY hkey;
    char temp[256], *btemp;

    if (port >= MAX_PORTS) return FALSE;
    temp[0] = 0;
    if (!RegOpenKeyA(HKEY_LOCAL_MACHINE, "Software\\Wine\\Wine\\Config\\serialports", &hkey))
    {
        DWORD type, count = sizeof(temp);
        char value[8];

        sprintf( value, "COM%d", port+1 );
        RegQueryValueExA(hkey, value, 0, &type, temp, &count);
        RegCloseKey(hkey);
    }
    if (!temp[0]) return FALSE;

    btemp = strchr(temp,',');
    if (btemp != NULL)
    {
        *btemp++ = '\0';
        if (baudrate) *baudrate = atoi(btemp);
    }
    else if (baudrate) *baudrate = -1;
    if (devicename) lstrcpynA( devicename, temp, size );
    return TRUE;
}

static BOOL get_lpt_device_name( int port, char *devicename, DWORD size )
{
    HKEY hkey;
    char temp[256];

    if (port >= MAX_PORTS) return FALSE;
    temp[0] = 0;
    if (!RegOpenKeyA(HKEY_LOCAL_MACHINE, "Software\\Wine\\Wine\\Config\\parallelports", &hkey))
    {
        DWORD type, count = sizeof(temp);
        char value[8];

        sprintf( value, "LPT%d", port+1 );
        RegQueryValueExA(hkey, value, 0, &type, temp, &count);
        RegCloseKey(hkey);
    }
    if (!temp[0]) return FALSE;

    if (devicename) lstrcpynA( devicename, temp, size );
    return TRUE;
}


static struct DosDeviceStruct *GetDeviceStruct(int index)
{
        if ((index&0x7F)<=MAX_PORTS) {
            if (!(index&FLAG_LPT)) {
                if (COM[index].handle)
                    return &COM[index];
            } else {
                index &= 0x7f;
                if (LPT[index].handle)
                    return &LPT[index];
            }
        }

        return NULL;
}

static int    GetCommPort_ov(LPOVERLAPPED ov, int write)
{
        int x;

        for (x=0; x<MAX_PORTS; x++) {
                if (ov == (write?&COM[x].write_ov:&COM[x].read_ov))
                        return x;
        }

        return -1;
}

inline static int ValidCOMPort(int x)
{
    return get_com_device_name( x, NULL, 0, NULL );
}

inline static int ValidLPTPort(int x)
{
    return get_lpt_device_name( x, NULL, 0 );
}

static int WinError(void)
{
        TRACE("errno = %d\n", errno);
        switch (errno) {
                default:
                        return CE_IOE;
                }
}

static unsigned comm_inbuf(struct DosDeviceStruct *ptr)
{
  return ((ptr->ibuf_tail > ptr->ibuf_head) ? ptr->ibuf_size : 0)
    + ptr->ibuf_head - ptr->ibuf_tail;
}

static unsigned comm_outbuf(struct DosDeviceStruct *ptr)
{
  return ((ptr->obuf_tail > ptr->obuf_head) ? ptr->obuf_size : 0)
    + ptr->obuf_head - ptr->obuf_tail;
}

static void comm_waitread(struct DosDeviceStruct *ptr);
static void comm_waitwrite(struct DosDeviceStruct *ptr);

static VOID WINAPI COMM16_ReadComplete(DWORD status, DWORD len, LPOVERLAPPED ov)
{
        int prev ;
        WORD mask = 0;
        int cid = GetCommPort_ov(ov,0);
        struct DosDeviceStruct *ptr;

        if(cid<0) {
                ERR("async write with bad overlapped pointer\n");
                return;
        }
        ptr = &COM[cid];

        /* we get cancelled when CloseComm is called */
        if (status==STATUS_CANCELLED)
        {
                TRACE("Cancelled\n");
                return;
        }

        /* read data from comm port */
        if (status != STATUS_SUCCESS) {
                ERR("async read failed %08lx\n",status);
                COM[cid].commerror = CE_RXOVER;
                return;
        }
        TRACE("async read completed %ld bytes\n",len);

        prev = comm_inbuf(ptr);

        /* check for events */
        if ((ptr->eventmask & EV_RXFLAG) &&
            memchr(ptr->inbuf + ptr->ibuf_head, ptr->evtchar, len)) {
                *(WORD*)(COM[cid].unknown) |= EV_RXFLAG;
                mask |= CN_EVENT;
        }
        if (ptr->eventmask & EV_RXCHAR) {
                *(WORD*)(COM[cid].unknown) |= EV_RXCHAR;
                mask |= CN_EVENT;
        }

        /* advance buffer position */
        ptr->ibuf_head += len;
        if (ptr->ibuf_head >= ptr->ibuf_size)
                ptr->ibuf_head = 0;

        /* check for notification */
        if (ptr->wnd && (ptr->n_read>0) && (prev<ptr->n_read) &&
            (comm_inbuf(ptr)>=ptr->n_read)) {
                /* passed the receive notification threshold */
                mask |= CN_RECEIVE;
        }

        /* send notifications, if any */
        if (ptr->wnd && mask) {
                TRACE("notifying %p: cid=%d, mask=%02x\n", ptr->wnd, cid, mask);
                PostMessageA(ptr->wnd, WM_COMMNOTIFY, cid, mask);
        }

        /* on real windows, this could cause problems, since it is recursive */
        /* restart the receive */
        comm_waitread(ptr);
}

/* this is meant to work like write() */
static INT COMM16_WriteFile(HANDLE hComm, LPCVOID buffer, DWORD len)
{
        OVERLAPPED ov;
        DWORD count= -1;

        ZeroMemory(&ov,sizeof(ov));
        ov.hEvent = CreateEventA(NULL,0,0,NULL);
        if(ov.hEvent==INVALID_HANDLE_VALUE)
                return -1;

        if(!WriteFile(hComm,buffer,len,&count,&ov))
        {
                if(GetLastError()==ERROR_IO_PENDING)
                {
                        GetOverlappedResult(hComm,&ov,&count,TRUE);
                }
        }
        CloseHandle(ov.hEvent);

        return count;
}

static VOID WINAPI COMM16_WriteComplete(DWORD status, DWORD len, LPOVERLAPPED ov)
{
        int prev, bleft;
        WORD mask = 0;
        int cid = GetCommPort_ov(ov,1);
        struct DosDeviceStruct *ptr;

        if(cid<0) {
                ERR("async write with bad overlapped pointer\n");
                return;
        }
        ptr = &COM[cid];

        /* read data from comm port */
        if (status != STATUS_SUCCESS) {
                ERR("async write failed\n");
                COM[cid].commerror = CE_RXOVER;
                return;
        }
        TRACE("async write completed %ld bytes\n",len);

        /* update the buffer pointers */
        prev = comm_outbuf(&COM[cid]);
        ptr->obuf_tail += len;
        if (ptr->obuf_tail >= ptr->obuf_size)
                ptr->obuf_tail = 0;

        /* write any TransmitCommChar character */
        if (ptr->xmit>=0) {
                len = COMM16_WriteFile(ptr->handle, &(ptr->xmit), 1);
                if (len > 0) ptr->xmit = -1;
        }

        /* write from output queue */
        bleft = ((ptr->obuf_tail <= ptr->obuf_head) ?
                ptr->obuf_head : ptr->obuf_size) - ptr->obuf_tail;

        /* check for notification */
        if (ptr->wnd && (ptr->n_write>0) && (prev>=ptr->n_write) &&
          (comm_outbuf(ptr)<ptr->n_write)) {
                /* passed the transmit notification threshold */
                mask |= CN_TRANSMIT;
        }

        /* send notifications, if any */
        if (ptr->wnd && mask) {
                TRACE("notifying %p: cid=%d, mask=%02x\n", ptr->wnd, cid, mask);
                PostMessageA(ptr->wnd, WM_COMMNOTIFY, cid, mask);
        }

        /* start again if necessary */
        if(bleft)
                comm_waitwrite(ptr);
}

static void comm_waitread(struct DosDeviceStruct *ptr)
{
        int bleft;
        COMSTAT stat;

        /* FIXME: get timeouts working properly so we can read bleft bytes */
        bleft = ((ptr->ibuf_tail > ptr->ibuf_head) ?
                (ptr->ibuf_tail-1) : ptr->ibuf_size) - ptr->ibuf_head;

        /* find out how many bytes are left in the buffer */
        if(ClearCommError(ptr->handle,NULL,&stat))
                bleft = (bleft<stat.cbInQue) ? bleft : stat.cbInQue;
        else
                bleft = 1;

        /* always read at least one byte */
        if(bleft==0)
                bleft++;

        ReadFileEx(ptr->handle,
                ptr->inbuf + ptr->ibuf_head,
                bleft,
                &ptr->read_ov,
                COMM16_ReadComplete);
}

static void comm_waitwrite(struct DosDeviceStruct *ptr)
{
        int bleft;

        bleft = ((ptr->obuf_tail <= ptr->obuf_head) ?
                ptr->obuf_head : ptr->obuf_size) - ptr->obuf_tail;
        WriteFileEx(ptr->handle,
                ptr->outbuf + ptr->obuf_tail,
                bleft,
                &ptr->write_ov,
                COMM16_WriteComplete);
}

/*****************************************************************************
 *      COMM16_DCBtoDCB16       (Internal)
 */
INT16 COMM16_DCBtoDCB16(LPDCB lpdcb, LPDCB16 lpdcb16)
{
        if(lpdcb->BaudRate<0x10000)
                lpdcb16->BaudRate = lpdcb->BaudRate;
        else if(lpdcb->BaudRate==115200)
                        lpdcb16->BaudRate = 57601;
        else {
                WARN("Baud rate can't be converted\n");
                lpdcb16->BaudRate = 57601;
        }
        lpdcb16->ByteSize = lpdcb->ByteSize;
        lpdcb16->fParity = lpdcb->fParity;
        lpdcb16->Parity = lpdcb->Parity;
        lpdcb16->StopBits = lpdcb->StopBits;

        lpdcb16->RlsTimeout = 50;
        lpdcb16->CtsTimeout = 50;
        lpdcb16->DsrTimeout = 50;
        lpdcb16->fNull = 0;
        lpdcb16->fChEvt = 0;
        lpdcb16->fBinary = 1;

        lpdcb16->fDtrflow = (lpdcb->fDtrControl==DTR_CONTROL_HANDSHAKE);
        lpdcb16->fRtsflow = (lpdcb->fRtsControl==RTS_CONTROL_HANDSHAKE);
        lpdcb16->fOutxCtsFlow = lpdcb->fOutxCtsFlow;
        lpdcb16->fOutxDsrFlow = lpdcb->fOutxDsrFlow;
        lpdcb16->fDtrDisable = (lpdcb->fDtrControl==DTR_CONTROL_DISABLE);

        lpdcb16->fInX = lpdcb->fInX;

        lpdcb16->fOutX = lpdcb->fOutX;
/*
        lpdcb16->XonChar =
        lpdcb16->XoffChar =
 */
        lpdcb16->XonLim = 10;
        lpdcb16->XoffLim = 10;

        return 0;
}


/**************************************************************************
 *         BuildCommDCB         (USER.213)
 *
 * According to the ECMA-234 (368.3) the function will return FALSE on
 * success, otherwise it will return -1.
 */
INT16 WINAPI BuildCommDCB16(LPCSTR device, LPDCB16 lpdcb)
{
        /* "COM1:96,n,8,1"      */
        /*  012345              */
        int port;
        DCB dcb;

        TRACE("(%s), ptr %p\n", device, lpdcb);

        if (strncasecmp(device,"COM",3))
                return -1;
        port = device[3] - '0';

        if (port-- == 0) {
                ERR("BUG ! COM0 can't exist!\n");
                return -1;
        }

        if (!ValidCOMPort(port)) {
                FIXME("invalid COM port %d?\n",port);
                return -1;
        }

        memset(lpdcb, 0, sizeof(DCB16)); /* initialize */

        lpdcb->Id = port;
        dcb.DCBlength = sizeof(DCB);

        if (strchr(device,'=')) /* block new style */
                return -1;

        if(!BuildCommDCBA(device,&dcb))
                return -1;

        return COMM16_DCBtoDCB16(&dcb, lpdcb);
}

/*****************************************************************************
 *      OpenComm                (USER.200)
 */
INT16 WINAPI OpenComm16(LPCSTR device,UINT16 cbInQueue,UINT16 cbOutQueue)
{
        int port;
        HANDLE handle;

        TRACE("%s, %d, %d\n", device, cbInQueue, cbOutQueue);

        if (strlen(device) < 4)
           return IE_BADID;

        port = device[3] - '0';

        if (port-- == 0)
                ERR("BUG ! COM0 or LPT0 don't exist !\n");

        if (!strncasecmp(device,"COM",3))
        {
                char devicename[32];
                int baudrate;

                if (!get_com_device_name( port, devicename, sizeof(devicename), &baudrate ))
                        return IE_BADID;

                TRACE("%s = %s\n", device, devicename);

                if (COM[port].handle)
                        return IE_OPEN;

                handle = CreateFileA(device, GENERIC_READ|GENERIC_WRITE,
                        FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, CREATE_ALWAYS,
                        FILE_FLAG_OVERLAPPED|FILE_FLAG_NO_BUFFERING, 0 );
                if (handle == INVALID_HANDLE_VALUE) {
                        ERR("Couldn't open %s ! (%s)\n", devicename, strerror(errno));
                        return IE_HARDWARE;
                } else {
                        memset(COM[port].unknown, 0, sizeof(COM[port].unknown));
                        COM[port].seg_unknown = 0;
                        COM[port].handle = handle;
                        COM[port].commerror = 0;
                        COM[port].eventmask = 0;
                        COM[port].evtchar = 0; /* FIXME: default? */
                        /* save terminal state */
                        GetCommState16(port,&COM[port].dcb);
                        /* set default parameters */
                        if(baudrate>-1){
                            DCB16 dcb;
                            memcpy(&dcb,&COM[port].dcb,sizeof(dcb));
                            dcb.BaudRate=baudrate;
                            /* more defaults:
                             * databits, parity, stopbits
                             */
                            SetCommState16( &dcb);
                        }
                        /* init priority characters */
                        COM[port].unget = -1;
                        COM[port].xmit = -1;
                        /* allocate buffers */
                        COM[port].ibuf_size = cbInQueue;
                        COM[port].ibuf_head = COM[port].ibuf_tail = 0;
                        COM[port].obuf_size = cbOutQueue;
                        COM[port].obuf_head = COM[port].obuf_tail = 0;

                        COM[port].inbuf = malloc(cbInQueue);
                        if (COM[port].inbuf) {
                          COM[port].outbuf = malloc(cbOutQueue);
                          if (!COM[port].outbuf)
                            free(COM[port].inbuf);
                        } else COM[port].outbuf = NULL;
                        if (!COM[port].outbuf) {
                          /* not enough memory */
                          SetCommState16(&COM[port].dcb);
                          CloseHandle(COM[port].handle);
                          ERR("out of memory\n");
                          return IE_MEMORY;
                        }

                        ZeroMemory(&COM[port].read_ov,sizeof (OVERLAPPED));
                        ZeroMemory(&COM[port].write_ov,sizeof (OVERLAPPED));

                        comm_waitread( &COM[port] );
                        USER16_AlertableWait++;

                        return port;
                }
        }
        else
        if (!strncasecmp(device,"LPT",3)) {

                if (!ValidLPTPort(port))
                        return IE_BADID;

                if (LPT[port].handle)
                        return IE_OPEN;

                handle = CreateFileA(device, GENERIC_READ|GENERIC_WRITE,
                        FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, CREATE_ALWAYS, 0, 0 );
                if (handle == INVALID_HANDLE_VALUE) {
                        return IE_HARDWARE;
                } else {
                        LPT[port].handle = handle;
                        LPT[port].commerror = 0;
                        LPT[port].eventmask = 0;
                        return port|FLAG_LPT;
                }
        }
        return IE_BADID;
}

/*****************************************************************************
 *      CloseComm               (USER.207)
 */
INT16 WINAPI CloseComm16(INT16 cid)
{
        struct DosDeviceStruct *ptr;

        TRACE("cid=%d\n", cid);
        if ((ptr = GetDeviceStruct(cid)) == NULL) {
                FIXME("no cid=%d found!\n", cid);
                return -1;
        }
        if (!(cid&FLAG_LPT)) {
                /* COM port */
                UnMapLS( COM[cid].seg_unknown );
                USER16_AlertableWait--;
                CancelIo(ptr->handle);

                /* free buffers */
                free(ptr->outbuf);
                free(ptr->inbuf);

                /* reset modem lines */
                SetCommState16(&COM[cid].dcb);
        }

        if (!CloseHandle(ptr->handle)) {
                ptr->commerror = WinError();
                /* FIXME: should we clear ptr->handle here? */
                return -1;
        } else {
                ptr->commerror = 0;
                ptr->handle = 0;
                return 0;
        }
}

/*****************************************************************************
 *      SetCommBreak            (USER.210)
 */
INT16 WINAPI SetCommBreak16(INT16 cid)
{
        struct DosDeviceStruct *ptr;

        TRACE("cid=%d\n", cid);
        if ((ptr = GetDeviceStruct(cid)) == NULL) {
                FIXME("no cid=%d found!\n", cid);
                return -1;
        }

        ptr->suspended = 1;
        ptr->commerror = 0;
        return 0;
}

/*****************************************************************************
 *      ClearCommBreak  (USER.211)
 */
INT16 WINAPI ClearCommBreak16(INT16 cid)
{
        struct DosDeviceStruct *ptr;

        TRACE("cid=%d\n", cid);
        if (!(ptr = GetDeviceStruct(cid))) {
                FIXME("no cid=%d found!\n", cid);
                return -1;
        }
        ptr->suspended = 0;
        ptr->commerror = 0;
        return 0;
}

/*****************************************************************************
 *      EscapeCommFunction      (USER.214)
 */
LONG WINAPI EscapeCommFunction16(UINT16 cid,UINT16 nFunction)
{
        struct  DosDeviceStruct *ptr;
        int     max;

        TRACE("cid=%d, function=%d\n", cid, nFunction);

        switch(nFunction) {
        case GETMAXCOM:
                TRACE("GETMAXCOM\n");
                for (max = MAX_PORTS;!ValidCOMPort(max);max--)
                        ;
                return max;

        case GETMAXLPT:
                TRACE("GETMAXLPT\n");
                for (max = MAX_PORTS;!ValidLPTPort(max);max--)
                        ;
                return FLAG_LPT + max;

        case GETBASEIRQ:
                TRACE("GETBASEIRQ\n");
                /* FIXME: use tables */
                /* just fake something for now */
                if (cid & FLAG_LPT) {
                        /* LPT1: irq 7, LPT2: irq 5 */
                        return (cid & 0x7f) ? 5 : 7;
                } else {
                        /* COM1: irq 4, COM2: irq 3,
                           COM3: irq 4, COM4: irq 3 */
                        return 4 - (cid & 1);
                }
        }

        if ((ptr = GetDeviceStruct(cid)) == NULL) {
                FIXME("no cid=%d found!\n", cid);
                return -1;
        }

        switch (nFunction) {
        case RESETDEV:
        case CLRDTR:
        case CLRRTS:
        case SETDTR:
        case SETRTS:
        case SETXOFF:
        case SETXON:
                if(EscapeCommFunction(ptr->handle,nFunction))
                        return 0;
                else {
                        ptr->commerror = WinError();
                        return -1;
                }

        case CLRBREAK:
        case SETBREAK:
        default:
                WARN("(cid=%d,nFunction=%d): Unknown function\n",
                        cid, nFunction);
        }
        return -1;
}

/*****************************************************************************
 *      FlushComm       (USER.215)
 */
INT16 WINAPI FlushComm16(INT16 cid,INT16 fnQueue)
{
        DWORD queue;
        struct DosDeviceStruct *ptr;

        TRACE("cid=%d, queue=%d\n", cid, fnQueue);
        if ((ptr = GetDeviceStruct(cid)) == NULL) {
                FIXME("no cid=%d found!\n", cid);
                return -1;
        }
        switch (fnQueue) {
        case 0:
                queue = PURGE_TXABORT;
                ptr->obuf_tail = ptr->obuf_head;
                break;
        case 1:
                queue = PURGE_RXABORT;
                ptr->ibuf_head = ptr->ibuf_tail;
                break;
        default:
                WARN("(cid=%d,fnQueue=%d):Unknown queue\n",
                            cid, fnQueue);
                return -1;
        }

        if (!PurgeComm(ptr->handle,queue)) {
                ptr->commerror = WinError();
                return -1;
        } else {
                ptr->commerror = 0;
                return 0;
        }
}

/********************************************************************
 *      GetCommError    (USER.203)
 */
INT16 WINAPI GetCommError16(INT16 cid,LPCOMSTAT16 lpStat)
{
        int             temperror;
        struct DosDeviceStruct *ptr;
        unsigned char *stol;

        if ((ptr = GetDeviceStruct(cid)) == NULL) {
                FIXME("no handle for cid = %0x!\n",cid);
                return -1;
        }
        if (cid&FLAG_LPT) {
            WARN(" cid %d not comm port\n",cid);
            return CE_MODE;
        }
        stol = (unsigned char *)COM[cid].unknown + COMM_MSR_OFFSET;
        COMM_MSRUpdate( ptr->handle, stol );

        if (lpStat) {
                lpStat->status = 0;

                SleepEx(1,TRUE);

                lpStat->cbOutQue = comm_outbuf(ptr);
                lpStat->cbInQue = comm_inbuf(ptr);

                TRACE("cid %d, error %d, stat %d in %d out %d, stol %x\n",
                             cid, ptr->commerror, lpStat->status, lpStat->cbInQue,
                             lpStat->cbOutQue, *stol);
        }
        else
                TRACE("cid %d, error %d, lpStat NULL stol %x\n",
                             cid, ptr->commerror, *stol);

        /* Return any errors and clear it */
        temperror = ptr->commerror;
        ptr->commerror = 0;
        return(temperror);
}

/*****************************************************************************
 *      SetCommEventMask        (USER.208)
 */
SEGPTR WINAPI SetCommEventMask16(INT16 cid,UINT16 fuEvtMask)
{
        struct DosDeviceStruct *ptr;
        unsigned char *stol;

        TRACE("cid %d,mask %d\n",cid,fuEvtMask);
        if ((ptr = GetDeviceStruct(cid)) == NULL) {
                FIXME("no handle for cid = %0x!\n",cid);
            return (SEGPTR)NULL;
        }

        ptr->eventmask = fuEvtMask;

        if ((cid&FLAG_LPT) || !ValidCOMPort(cid)) {
            WARN(" cid %d not comm port\n",cid);
            return (SEGPTR)NULL;
        }
        /* it's a COM port ? -> modify flags */
        stol = (unsigned char *)COM[cid].unknown + COMM_MSR_OFFSET;
        COMM_MSRUpdate( ptr->handle, stol );

        TRACE(" modem dcd construct %x\n",*stol);
        if (!COM[cid].seg_unknown) COM[cid].seg_unknown = MapLS( COM[cid].unknown );
        return COM[cid].seg_unknown;
}

/*****************************************************************************
 *      GetCommEventMask        (USER.209)
 */
UINT16 WINAPI GetCommEventMask16(INT16 cid,UINT16 fnEvtClear)
{
        struct DosDeviceStruct *ptr;
        WORD events;

        TRACE("cid %d, mask %d\n", cid, fnEvtClear);
        if ((ptr = GetDeviceStruct(cid)) == NULL) {
                FIXME("no handle for cid = %0x!\n",cid);
            return 0;
        }

        if ((cid&FLAG_LPT) || !ValidCOMPort(cid)) {
            WARN(" cid %d not comm port\n",cid);
            return 0;
        }

        events = *(WORD*)(COM[cid].unknown) & fnEvtClear;
        *(WORD*)(COM[cid].unknown) &= ~fnEvtClear;
        return events;
}

/*****************************************************************************
 *      SetCommState    (USER.201)
 */
INT16 WINAPI SetCommState16(LPDCB16 lpdcb)
{
        struct DosDeviceStruct *ptr;
        DCB dcb;

        TRACE("cid %d, ptr %p\n", lpdcb->Id, lpdcb);
        if ((ptr = GetDeviceStruct(lpdcb->Id)) == NULL) {
                FIXME("no handle for cid = %0x!\n",lpdcb->Id);
                return -1;
        }

        memset(&dcb,0,sizeof(dcb));
        dcb.DCBlength = sizeof(dcb);

        /*
         * according to MSDN, we should first interpret lpdcb->BaudRate as follows:
         * 1. if the baud rate is a CBR constant, interpret it.
         * 2. if it is greater than 57600, the baud rate is 115200
         * 3. use the actual baudrate
         * steps 2 and 3 are equivilent to 16550 baudrate divisor = 115200/BaudRate
         * see http://support.microsoft.com/support/kb/articles/q108/9/28.asp
         */
        switch(lpdcb->BaudRate)
        {
        case CBR_110:    dcb.BaudRate = 110;    break;
        case CBR_300:    dcb.BaudRate = 300;    break;
        case CBR_600:    dcb.BaudRate = 600;    break;
        case CBR_1200:   dcb.BaudRate = 1200;   break;
        case CBR_2400:   dcb.BaudRate = 2400;   break;
        case CBR_4800:   dcb.BaudRate = 4800;   break;
        case CBR_9600:   dcb.BaudRate = 9600;   break;
        case CBR_14400:  dcb.BaudRate = 14400;  break;
        case CBR_19200:  dcb.BaudRate = 19200;  break;
        case CBR_38400:  dcb.BaudRate = 38400;  break;
        case CBR_56000:  dcb.BaudRate = 56000;  break;
        case CBR_128000: dcb.BaudRate = 128000; break;
        case CBR_256000: dcb.BaudRate = 256000; break;
        default:
                if(lpdcb->BaudRate>57600)
                dcb.BaudRate = 115200;
        else
                dcb.BaudRate = lpdcb->BaudRate;
        }

        dcb.ByteSize=lpdcb->ByteSize;
        dcb.StopBits=lpdcb->StopBits;

        dcb.fParity=lpdcb->fParity;
        dcb.Parity=lpdcb->Parity;

        dcb.fOutxCtsFlow = lpdcb->fOutxCtsFlow;

        if (lpdcb->fDtrflow || lpdcb->fRtsflow)
                dcb.fRtsControl = TRUE;

        if (lpdcb->fDtrDisable)
                dcb.fDtrControl = TRUE;

        ptr->evtchar = lpdcb->EvtChar;

        dcb.fInX = lpdcb->fInX;
        dcb.fOutX = lpdcb->fOutX;

        if (!SetCommState(ptr->handle,&dcb)) {
                ptr->commerror = WinError();
                return -1;
        } else {
                ptr->commerror = 0;
                return 0;
        }
}

/*****************************************************************************
 *      GetCommState    (USER.202)
 */
INT16 WINAPI GetCommState16(INT16 cid, LPDCB16 lpdcb)
{
        struct DosDeviceStruct *ptr;
        DCB dcb;

        TRACE("cid %d, ptr %p\n", cid, lpdcb);
        if ((ptr = GetDeviceStruct(cid)) == NULL) {
                FIXME("no handle for cid = %0x!\n",cid);
                return -1;
        }
        if (!GetCommState(ptr->handle,&dcb)) {
                ptr->commerror = WinError();
                return -1;
        }

        lpdcb->Id = cid;

        COMM16_DCBtoDCB16(&dcb,lpdcb);

        lpdcb->EvtChar = ptr->evtchar;

        ptr->commerror = 0;
        return 0;
}

/*****************************************************************************
 *      TransmitCommChar        (USER.206)
 */
INT16 WINAPI TransmitCommChar16(INT16 cid,CHAR chTransmit)
{
        struct DosDeviceStruct *ptr;

        TRACE("cid %d, data %d \n", cid, chTransmit);
        if ((ptr = GetDeviceStruct(cid)) == NULL) {
                FIXME("no handle for cid = %0x!\n",cid);
                return -1;
        }

        if (ptr->suspended) {
                ptr->commerror = IE_HARDWARE;
                return -1;
        }

        if (ptr->xmit >= 0) {
          /* character already queued */
          /* FIXME: which error would Windows return? */
          ptr->commerror = CE_TXFULL;
          return -1;
        }

        if (ptr->obuf_head == ptr->obuf_tail) {
          /* transmit queue empty, try to transmit directly */
          if(1!=COMM16_WriteFile(ptr->handle, &chTransmit, 1))
          {
            /* didn't work, queue it */
            ptr->xmit = chTransmit;
            comm_waitwrite(ptr);
          }
        } else {
          /* data in queue, let this char be transmitted next */
          ptr->xmit = chTransmit;
          comm_waitwrite(ptr);
        }

        ptr->commerror = 0;
        return 0;
}

/*****************************************************************************
 *      UngetCommChar   (USER.212)
 */
INT16 WINAPI UngetCommChar16(INT16 cid,CHAR chUnget)
{
        struct DosDeviceStruct *ptr;

        TRACE("cid %d (char %d)\n", cid, chUnget);
        if ((ptr = GetDeviceStruct(cid)) == NULL) {
                FIXME("no handle for cid = %0x!\n",cid);
                return -1;
        }

        if (ptr->suspended) {
                ptr->commerror = IE_HARDWARE;
                return -1;
        }

        if (ptr->unget>=0) {
          /* character already queued */
          /* FIXME: which error would Windows return? */
          ptr->commerror = CE_RXOVER;
          return -1;
        }

        ptr->unget = chUnget;

        ptr->commerror = 0;
        return 0;
}

/*****************************************************************************
 *      ReadComm        (USER.204)
 */
INT16 WINAPI ReadComm16(INT16 cid,LPSTR lpvBuf,INT16 cbRead)
{
        int status, length;
        struct DosDeviceStruct *ptr;
        LPSTR orgBuf = lpvBuf;

        TRACE("cid %d, ptr %p, length %d\n", cid, lpvBuf, cbRead);
        if ((ptr = GetDeviceStruct(cid)) == NULL) {
                FIXME("no handle for cid = %0x!\n",cid);
                return -1;
        }

        if (ptr->suspended) {
                ptr->commerror = IE_HARDWARE;
                return -1;
        }

        if(0==comm_inbuf(ptr))
                SleepEx(1,TRUE);

        /* read unget character */
        if (ptr->unget>=0) {
                *lpvBuf++ = ptr->unget;
                ptr->unget = -1;

                length = 1;
        } else
                length = 0;

        /* read from receive buffer */
        while (length < cbRead) {
          status = ((ptr->ibuf_head < ptr->ibuf_tail) ?
                    ptr->ibuf_size : ptr->ibuf_head) - ptr->ibuf_tail;
          if (!status) break;
          if ((cbRead - length) < status)
            status = cbRead - length;

          memcpy(lpvBuf, ptr->inbuf + ptr->ibuf_tail, status);
          ptr->ibuf_tail += status;
          if (ptr->ibuf_tail >= ptr->ibuf_size)
            ptr->ibuf_tail = 0;
          lpvBuf += status;
          length += status;
        }

        TRACE("%s\n", debugstr_an( orgBuf, length ));
        ptr->commerror = 0;
        return length;
}

/*****************************************************************************
 *      WriteComm       (USER.205)
 */
INT16 WINAPI WriteComm16(INT16 cid, LPSTR lpvBuf, INT16 cbWrite)
{
        int status, length;
        struct DosDeviceStruct *ptr;

        TRACE("cid %d, ptr %p, length %d\n",
                cid, lpvBuf, cbWrite);
        if ((ptr = GetDeviceStruct(cid)) == NULL) {
                FIXME("no handle for cid = %0x!\n",cid);
                return -1;
        }

        if (ptr->suspended) {
                ptr->commerror = IE_HARDWARE;
                return -1;
        }

        TRACE("%s\n", debugstr_an( lpvBuf, cbWrite ));

        length = 0;
        while (length < cbWrite) {
          if ((ptr->obuf_head == ptr->obuf_tail) && (ptr->xmit < 0)) {
            /* no data queued, try to write directly */
            status = COMM16_WriteFile(ptr->handle, lpvBuf, cbWrite - length);
            if (status > 0) {
              lpvBuf += status;
              length += status;
              continue;
            }
          }
          /* can't write directly, put into transmit buffer */
          status = ((ptr->obuf_tail > ptr->obuf_head) ?
                    (ptr->obuf_tail-1) : ptr->obuf_size) - ptr->obuf_head;
          if (!status) break;
          if ((cbWrite - length) < status)
            status = cbWrite - length;
          memcpy(lpvBuf, ptr->outbuf + ptr->obuf_head, status);
          ptr->obuf_head += status;
          if (ptr->obuf_head >= ptr->obuf_size)
            ptr->obuf_head = 0;
          lpvBuf += status;
          length += status;
          comm_waitwrite(ptr);
        }

        ptr->commerror = 0;
        return length;
}

/***********************************************************************
 *           EnableCommNotification   (USER.245)
 */
BOOL16 WINAPI EnableCommNotification16( INT16 cid, HWND16 hwnd,
                                      INT16 cbWriteNotify, INT16 cbOutQueue )
{
        struct DosDeviceStruct *ptr;

        TRACE("(%d, %x, %d, %d)\n", cid, hwnd, cbWriteNotify, cbOutQueue);
        if ((ptr = GetDeviceStruct(cid)) == NULL) {
                FIXME("no handle for cid = %0x!\n",cid);
                return -1;
        }
        ptr->wnd = WIN_Handle32( hwnd );
        ptr->n_read = cbWriteNotify;
        ptr->n_write = cbOutQueue;
        return TRUE;
}