dosfns.c

开源DOS的C代码源程序

0000 0010 replace O_TRUNC

0001 0000 create new file O_CREAT
0001 0001 create if not exists, open if exists O_CREAT | O_OPEN
0001 0010 create O_CREAT | O_TRUNC

bits for flags (bits 11-8 are internal FreeDOS bits only)
15 O_FCB  called from FCB open
14 O_SYNC commit for each write (not implemented yet)
13 O_NOCRIT do not invoke int23 (not implemented yet)
12 O_LARGEFILE allow files >= 2gb but < 4gb (not implemented yet)
11 O_LEGACY not called from int21/ah=6c: find right fn for redirector
10 O_CREAT if file does not exist, create it
9 O_TRUNC if file exists, truncate and open it \ not both 
8 O_OPEN  if file exists, open it              /
7 O_NOINHERIT do not inherit handle on exec
6 \ 
5  - sharing modes
4 / 
3 reserved 
2 bits 2,1,0 = 100: RDONLY and do not modify file's last access time
                    (not implemented yet)
1 \ 0=O_RDONLY, 1=O_WRONLY,
0 / 2=O_RDWR, 3=O_EXECCASE (preserve case for redirector EXEC,
                            (not implemented yet))
*/

long DosOpenSft(char FAR * fname, unsigned flags, unsigned attrib)
{
  COUNT sft_idx;
  sft FAR *sftp;
  struct dhdr FAR *dhp;
  long result;

  result = truename(fname, PriPathName, CDS_MODE_CHECK_DEV_PATH);
  if (result < SUCCESS)
    return result;

  /* now get a free system file table entry       */
  if ((sftp = get_free_sft(&sft_idx)) == (sft FAR *) - 1)
    return DE_TOOMANY;

  fmemset(sftp, 0, sizeof(sft));

  sftp->sft_psp = cu_psp;
  sftp->sft_mode = flags & 0xf0ff;
  OpenMode = (BYTE) flags;

  sftp->sft_shroff = -1;        /* /// Added for SHARE - Ron Cemer */
  sftp->sft_attrib = attrib = attrib | D_ARCHIVE;

  if (result & IS_NETWORK)
  {
    int status;
    unsigned cmd;
    if ((flags & (O_TRUNC | O_CREAT)) == O_CREAT)
      attrib |= 0x100;

    lpCurSft = sftp;
    cmd = REM_CREATE;
    if (!(flags & O_LEGACY))
    {
      extern UWORD ASM ext_open_mode, ASM ext_open_attrib, ASM ext_open_action;
      ext_open_mode = flags & 0x70ff;
      ext_open_attrib = attrib & 0xff;
      ext_open_action = ((flags & 0x0300) >> 8) | ((flags & O_CREAT) >> 6);
      cmd = REM_EXTOC;
    }
    else if (!(flags & O_CREAT))
    {
      cmd = REM_OPEN;
      attrib = (BYTE)flags;
    }
    status = (int)network_redirector_mx(cmd, sftp, (void *)attrib);
    if (status >= SUCCESS)
    {
      if (sftp->sft_count == 0)
        sftp->sft_count++;
      return sft_idx | ((long)status << 16);
    }
    return status;
  }

  /* check for a device   */
  if ((result & IS_DEVICE) && (dhp = IsDevice(fname)) != NULL)
  {
    int rc = DeviceOpenSft(dhp, sftp);
    /* check the status code returned by the
     * driver when we tried to open it
     */
    if (rc < SUCCESS)
      return rc;
    return sft_idx;
  }

/* /// Added for SHARE.  - Ron Cemer */
  if (IsShareInstalled())
  {
    if ((sftp->sft_shroff =
         share_open_check(PriPathName, cu_psp,
                          flags & 0x03, (flags >> 4) & 0x07)) < 0)
      return sftp->sft_shroff;
  }
  
/* /// End of additions for SHARE.  - Ron Cemer */

  /* NEVER EVER allow directories to be created */
  /* ... though FCB's are weird :) */
  if (!(flags & O_FCB) &&
      (attrib & ~(D_RDONLY | D_HIDDEN | D_SYSTEM | D_ARCHIVE | D_VOLID)))
    return DE_ACCESS;
  
  result = dos_open(PriPathName, flags, attrib);
  if (result >= 0)
  {
    int status = (int)(result >> 16);
    if (status == S_OPENED)
    {
      sftp->sft_attrib = dos_getfattr_fd((COUNT)result);
      /* Check permissions. -- JPP
         (do not allow to open volume labels/directories) */
      if (sftp->sft_attrib & (D_DIR | D_VOLID))
      {
        dos_close((COUNT)result);
        return DE_ACCESS;
      }
      sftp->sft_size = dos_getfsize((COUNT)result);
    }
    sftp->sft_status = (COUNT)result;
    sftp->sft_flags = PriPathName[0] - 'A';
    sftp->sft_count += 1;
    DosGetFile(PriPathName, sftp->sft_name);
    dos_getftime(sftp->sft_status,
                 (date FAR *) & sftp->sft_date,
                 (time FAR *) & sftp->sft_time);
    return sft_idx | ((long)status << 16);
  }
  else
  {
/* /// Added for SHARE *** CURLY BRACES ADDED ALSO!!! ***.  - Ron Cemer */
    if (IsShareInstalled())
    {
      share_close_file(sftp->sft_shroff);
      sftp->sft_shroff = -1;
    }
/* /// End of additions for SHARE.  - Ron Cemer */
    return result;
  }    
}

long DosOpen(char FAR * fname, unsigned mode, unsigned attrib)
{
  long result;
  unsigned hndl;
  
  /* test if mode is in range                     */
  if ((mode & ~O_VALIDMASK) != 0)
    return DE_INVLDACC;

  /* get a free handle  */
  if ((result = get_free_hndl()) < 0)
    return result;
  hndl = (unsigned)result;

  result = DosOpenSft(fname, mode, attrib);
  if (result < SUCCESS)
    return result;

  ((psp FAR *)MK_FP(cu_psp, 0))->ps_filetab[hndl] = (UBYTE)result;
  return hndl | (result & 0xffff0000l);
}

COUNT CloneHandle(unsigned hndl)
{
  /* now get the system file table entry                          */
  sft FAR *sftp = get_sft(hndl);

  if (sftp == (sft FAR *) -1 || (sftp->sft_mode & O_NOINHERIT))
    return DE_INVLDHNDL;
  
  /* now that we have the system file table entry, get the fnode  */
  /* index, and increment the count, so that we've effectively    */
  /* cloned the file.                                             */
  sftp->sft_count += 1;
  return SUCCESS;
}

long DosDup(unsigned Handle)
{
  long NewHandle;

  if ((NewHandle = get_free_hndl()) < 0)
    return NewHandle;

  if (DosForceDup(Handle, (unsigned)NewHandle) < 0)
    return DE_INVLDHNDL;
  else
    return NewHandle;
}

COUNT DosForceDup(unsigned OldHandle, unsigned NewHandle)
{
  psp FAR *p = MK_FP(cu_psp, 0);
  sft FAR *Sftp;

  /* Get the SFT block that contains the SFT                      */
  if ((Sftp = get_sft(OldHandle)) == (sft FAR *) - 1)
    return DE_INVLDHNDL;

  /* now close the new handle if it's open                        */
  if ((UBYTE) p->ps_filetab[NewHandle] != 0xff)
  {
    COUNT ret;

    if ((ret = DosClose(NewHandle)) != SUCCESS)
      return ret;
  }

  /* If everything looks ok, bump it up.                          */
  if ((Sftp->sft_flags & (SFT_FDEVICE | SFT_FSHARED))
      || (Sftp->sft_status >= 0))
  {
    p->ps_filetab[NewHandle] = p->ps_filetab[OldHandle];
    /* possible hazard: integer overflow ska*/
    Sftp->sft_count += 1;
    return SUCCESS;
  }
  else
    return DE_INVLDHNDL;
}

COUNT DosCloseSft(int sft_idx, BOOL commitonly)
{
  sft FAR *sftp = idx_to_sft(sft_idx);

  if (FP_OFF(sftp) == (size_t) - 1)
    return DE_INVLDHNDL;

  lpCurSft = sftp;
/*
   remote sub sft_count.
 */
  if (sftp->sft_flags & SFT_FSHARED)
  {
    /* printf("closing SFT %d = %p\n",sft_idx,sftp); */
    return network_redirector_fp(commitonly ? REM_FLUSH: REM_CLOSE, sftp);
  }

  /* now just drop the count if a device, else    */
  /* call file system handler                     */
  if (!commitonly)
    sftp->sft_count -= 1;

  if (sftp->sft_flags & SFT_FDEVICE)
  {
    if (sftp->sft_dev->dh_attr & SFT_FOCRM)
    {
      /* if Open/Close/RM bit in driver's attribute is set
       * then issue a Close request to the driver
       */
      struct dhdr FAR *dev = sftp->sft_dev;
      if (BinaryCharIO(&dev, 0, MK_FP(0x0000, 0x0000), C_CLOSE) != SUCCESS)
        return DE_ACCESS;
    }
    return SUCCESS;
  }
  if (commitonly || sftp->sft_count > 0)
    return dos_commit(sftp->sft_status);

/* /// Added for SHARE *** CURLY BRACES ADDED ALSO!!! ***.  - Ron Cemer */
  if (IsShareInstalled())
  {
    if (sftp->sft_shroff >= 0)
      share_close_file(sftp->sft_shroff);
    sftp->sft_shroff = -1;
  }
/* /// End of additions for SHARE.  - Ron Cemer */
  return dos_close(sftp->sft_status);
}

COUNT DosClose(COUNT hndl)
{
  psp FAR *p = MK_FP(cu_psp, 0);
  COUNT ret;

  /* Get the SFT block that contains the SFT      */
  ret = DosCloseSft(get_sft_idx(hndl), FALSE);
  if (ret != DE_INVLDHNDL && ret != DE_ACCESS)
    p->ps_filetab[hndl] = 0xff;
  return ret;
}

BOOL DosGetFree(UBYTE drive, UWORD * spc, UWORD * navc,
                UWORD * bps, UWORD * nc)
{
  /* navc==NULL means: called from FatGetDrvData, fcbfns.c */
  struct dpb FAR *dpbp;
  struct cds FAR *cdsp;
  COUNT rg[4];

  /* next - "log" in the drive            */
  drive = (drive == 0 ? default_drive : drive - 1);

  /* first check for valid drive          */
  *spc = -1;
  cdsp = get_cds(drive);

  if (cdsp == NULL)
    return FALSE;

  if (cdsp->cdsFlags & CDSNETWDRV)
  {
    if (remote_getfree(cdsp, rg) != SUCCESS)
      return FALSE;

    /* for int21/ah=1c:
       Undoc DOS says, its not supported for
       network drives. so it's probably OK */
    /* some programs such as RHIDE want it though and
       the redirector can provide all info
       - Bart, 2002 Apr 1 */

    if (navc != NULL)
    {
      *navc = (COUNT) rg[3];
      *spc &= 0xff; /* zero out media ID byte */
    }

    *spc = (COUNT) rg[0];
    *nc = (COUNT) rg[1];
    *bps = (COUNT) rg[2];
    return TRUE;
  }

  dpbp = cdsp->cdsDpb;
  if (dpbp == NULL)
    return FALSE;

  if (navc == NULL)
  {
      /* hazard: no error checking! */
    flush_buffers(dpbp->dpb_unit);
    dpbp->dpb_flags = M_CHANGED;
  }

  if (media_check(dpbp) < 0)
    return FALSE;
  /* get the data available from dpb      */
  *spc = (dpbp->dpb_clsmask + 1);
  *bps = dpbp->dpb_secsize;

  /* now tell fs to give us free cluster  */
  /* count                                */
#ifdef WITHFAT32
  if (ISFAT32(dpbp))
  {
    ULONG cluster_size, ntotal, nfree;

    /* we shift ntotal until it is equal to or below 0xfff6 */
    cluster_size = (ULONG) dpbp->dpb_secsize << dpbp->dpb_shftcnt;
    ntotal = dpbp->dpb_xsize - 1;
    if (navc != NULL)
      nfree = dos_free(dpbp);
    while (ntotal > FAT_MAGIC16 && cluster_size < 0x8000)
    {
      cluster_size <<= 1;
      *spc <<= 1;
      ntotal >>= 1;
      nfree >>= 1;
    }
    /* get the data available from dpb      */
    *nc = ntotal > FAT_MAGIC16 ? FAT_MAGIC16 : (UCOUNT) ntotal;

    /* now tell fs to give us free cluster  */
    /* count                                */
    if (navc != NULL)
      *navc = nfree > FAT_MAGIC16 ? FAT_MAGIC16 : (UCOUNT) nfree;
    return TRUE;
  }
#endif
  /* a passed nc of 0xffff means: skip free; see FatGetDrvData
     fcbfns.c */
  if (*nc != 0xffff)
    *navc = (COUNT) dos_free(dpbp);
  *nc = dpbp->dpb_size - 1;
  if (*spc > 64)
  {
    /* fake for 64k clusters do confuse some DOS programs, but let
       others work without overflowing */
    *spc >>= 1;
    *navc = ((unsigned)*navc < FAT_MAGIC16 / 2) ? ((unsigned)*navc << 1) : FAT_MAGIC16;
    *nc = ((unsigned)*nc < FAT_MAGIC16 / 2) ? ((unsigned)*nc << 1) : FAT_MAGIC16;
  }
  return TRUE;
}

#ifdef WITHFAT32
/* network names like \\SERVER\C aren't supported yet */
#define IS_SLASH(ch) (ch == '\\' || ch == '/')
COUNT DosGetExtFree(BYTE FAR * DriveString, struct xfreespace FAR * xfsp)
{
  struct dpb FAR *dpbp;
  struct cds FAR *cdsp;
  UCOUNT rg[4];

  if (IS_SLASH(DriveString[0]) || !IS_SLASH(DriveString[2])
      || DriveString[1] != ':')
    return DE_INVLDDRV;

  cdsp = get_cds(DosUpFChar(*DriveString) - 'A');

  if (cdsp == NULL)
    return DE_INVLDDRV;

  if (cdsp->cdsFlags & CDSNETWDRV)
  {
    if (remote_getfree(cdsp, rg) != SUCCESS)
      return DE_INVLDDRV;

    xfsp->xfs_clussize = rg[0];
    xfsp->xfs_totalclusters = rg[1];
    xfsp->xfs_secsize = rg[2];
    xfsp->xfs_freeclusters = rg[3];
  }
  else
  {
    dpbp = cdsp->cdsDpb;
    if (dpbp == NULL || media_check(dpbp) < 0)
      return DE_INVLDDRV;
    xfsp->xfs_secsize = dpbp->dpb_secsize;
    xfsp->xfs_totalclusters =
        (ISFAT32(dpbp) ? dpbp->dpb_xsize : dpbp->dpb_size);
    xfsp->xfs_freeclusters = dos_free(dpbp);
    xfsp->xfs_clussize = dpbp->dpb_clsmask + 1;
  }
  xfsp->xfs_totalunits = xfsp->xfs_totalclusters;
  xfsp->xfs_freeunits = xfsp->xfs_freeclusters;
  xfsp->xfs_totalsectors = xfsp->xfs_totalclusters * xfsp->xfs_clussize;
  xfsp->xfs_freesectors = xfsp->xfs_freeclusters * xfsp->xfs_clussize;
  xfsp->xfs_datasize = sizeof(struct xfreespace);

  fmemset(xfsp->xfs_reserved, 0, 8);

  return SUCCESS;
}
#endif

COUNT DosGetCuDir(UBYTE drive, BYTE FAR * s)
{
  BYTE *cp;
  struct cds FAR *cdsp;

  /* next - "log" in the drive            */
  /* first check for valid drive          */
  cdsp = get_cds(drive == 0 ? default_drive : drive - 1);
  if (cdsp == NULL)
    return DE_INVLDDRV;

  fmemcpy(&TempCDS, cdsp, sizeof(TempCDS));
  cp = TempCDS.cdsCurrentPath;
  /* ensure termination of fstrcpy */
  cp[MAX_CDSPATH - 1] = '\0';

  if ((TempCDS.cdsFlags & CDSNETWDRV) == 0)
  {
    /* dos_cd ensures that the path exists; if not, we
       need to change to the root directory */
    int result = dos_cd(cp);
    if (result == DE_PATHNOTFND)
      cp[TempCDS.cdsBackslashOffset + 1] =
        cdsp->cdsCurrentPath[TempCDS.cdsBackslashOffset + 1] = '\0';
    else if (result < SUCCESS)
      return result;
  }

  cp += TempCDS.cdsBackslashOffset;
  if (*cp == '\0')
    s[0] = '\0';
  else
    fstrcpy(s, cp + 1);

  return SUCCESS;
}

#undef CHDIR_DEBUG
COUNT DosChangeDir(BYTE FAR * s)