rom/dos/setvbuf.c

   1 /*
   2     Copyright © 1995-2011, The AROS Development Team. All rights reserved.
   3     $Id$
   4 */
   5
   6 #include <aros/debug.h>
   7
   8 #include <proto/exec.h>
   9
  10 #include "dos_intern.h"
  11
  12 /*****************************************************************************
  13
  14     NAME */
  15 #include <dos/stdio.h>
  16 #include <proto/dos.h>
  17
  18         AROS_LH4(LONG, SetVBuf,
  19
  20 /*        SetVBuf -- set buffering modes and size */
  21
  22 /*  SYNOPSIS */
  23         AROS_LHA(BPTR  , file, D1),
  24         AROS_LHA(STRPTR, buff, D2),
  25         AROS_LHA(LONG  , type, D3),
  26         AROS_LHA(LONG  , size, D4),
  27
  28 /*  LOCATION */
  29         struct DosLibrary *, DOSBase, 61, Dos)
  30
  31 /*  FUNCTION
  32         Changes the buffering modes and buffer size for a filehandle.
  33         With buff == NULL, the current buffer will be deallocated (if it
  34         was not a user-supplied one) and a new one of (approximately) size
  35         will be allocated. If buffer is non-NULL, it will be used for
  36         buffering and must be at least max(size,208) bytes long, and MUST
  37         be longword aligned. If size is -1, then only the buffering mode
  38         will be changed.
  39
  40     INPUTS
  41         file - Filehandle
  42         buff - buffer pointer for buffered I/O or NULL.
  43         type - buffering mode (see <dos/stdio.h>)
  44         size - size of buffer for buffered I/O (sizes less than 208 bytes
  45                will be rounded up to 208), or -1.
  46
  47     RESULT
  48         0 if operation succeeded.
  49
  50 *****************************************************************************/
  51 {
  52     AROS_LIBFUNC_INIT
  53
  54     struct FileHandle *fh = (struct FileHandle *)BADDR(file);
  55
  56     if (fh == NULL)
  57         return EOF;
  58
  59     ASSERT_VALID_PTR( fh );
  60     ASSERT_VALID_PTR_OR_NULL(buff);
  61
  62     D(bug("[SetVBuf] file=%p, buff=%p (was %p), mode=%d (flags 0x%x), size %d (was %d)\n", file, buff, BADDR(fh->fh_Buf), type, fh->fh_Flags, size, fh->fh_BufSize));
  63
  64     /* Ensure that buff is BPTR aligned */
  65     if (buff != BADDR(MKBADDR(buff)))
  66         return EOF;
  67
  68     switch (type)
  69     {
  70         case BUF_LINE:
  71             fh->fh_Flags = (fh->fh_Flags & ~FHF_NOBUF) | FHF_LINEBUF;
  72             break;
  73
  74         case BUF_FULL:
  75             fh->fh_Flags = fh->fh_Flags & ~(FHF_NOBUF | FHF_LINEBUF);
  76             break;
  77
  78         case BUF_NONE:
  79             fh->fh_Flags = (fh->fh_Flags | FHF_NOBUF) & ~FHF_LINEBUF;
  80             break;
  81
  82         default:
  83             return EOF;
  84     }
  85
  86     if (size >= 0)
  87     {
  88         if (fh->fh_OrigBuf == fh->fh_Buf) {
  89             vbuf_free(fh);
  90         } else {
  91             /* Not ours, so we're not going to free it. */
  92         }
  93         if (!vbuf_alloc(fh, buff, size))
  94             return EOF;
  95     }
  96
  97     return 0;
  98
  99     AROS_LIBFUNC_EXIT
 100 } /* SetVBuf */
 101
 102
 103 void
 104 vbuf_free(FileHandlePtr fh)
 105 {
 106     if (fh->fh_Flags & FHF_BUF)
 107     {
 108         /* free buffer allocated by system */
 109         if (fh->fh_Flags & FHF_OWNBUF)
 110             FreeMem(BADDR(fh->fh_Buf), fh->fh_BufSize);
 111
 112         fh->fh_Buf = BNULL;
 113         fh->fh_Pos = fh->fh_End = 0;
 114         fh->fh_BufSize = 0;
 115         fh->fh_OrigBuf = BNULL;
 116     }
 117
 118     fh->fh_Flags &= ~(FHF_BUF | FHF_OWNBUF);
 119 }
 120
 121 APTR vbuf_alloc(FileHandlePtr fh, STRPTR buf, ULONG size)
 122 {
 123     ULONG flags = FHF_BUF;
 124
 125     if (size < 208)
 126         size = 208;
 127
 128     if (!buf)
 129     {
 130         buf = AllocMem(size, MEMF_ANY);
 131         fh->fh_OrigBuf = MKBADDR(buf);
 132         flags |= FHF_OWNBUF;
 133     }
 134
 135     if (NULL != buf)
 136     {
 137         fh->fh_BufSize = size;
 138         fh->fh_Flags  |= flags;
 139         fh->fh_Buf     = MKBADDR(buf);
 140         fh->fh_Pos     = 0;
 141         fh->fh_End     = (fh->fh_Flags & FHF_WRITE) ? fh->fh_BufSize : 0;
 142     }
 143
 144     return buf;
 145 }
 146
 147 BOOL vbuf_inject(BPTR fh, CONST_STRPTR argptr, ULONG size, struct DosLibrary *DOSBase)
 148 {
 149     FileHandlePtr fhinput;
 150     STRPTR buf;
 151
 152     if (!fh || !argptr)
 153         return FALSE;
 154     fhinput = BADDR(fh);
 155
 156     /* Handle the trivial case, where we have enough room
 157      * in the minimal buffer.
 158      *
 159      * For AOS 1.3 C:Run compatabilty, the injected buffer
 160      * MUST start at Pos==0. Yes, that stupid command does
 161      * not check that fh_Pos is nonzero.
 162      */
 163     if ((fhinput->fh_Flags & FHF_BUF) && size <= 208) {
 164         CopyMem(argptr, BADDR(fhinput->fh_Buf), size);
 165         fhinput->fh_Pos = 0;
 166         fhinput->fh_End = size;
 167         return TRUE;
 168     }
 169
 170     /* Check to see if this FileHandle has been mangled
 171      * by someone else. BCPL programs like to do this,
 172      * to work around argument injection issues with the
 173      * old BCPL version of RunCommand.
 174      */
 175     if (fhinput->fh_Flags & FHF_BUF) {
 176         if (fhinput->fh_Flags & FHF_OWNBUF) {
 177             if (fhinput->fh_Buf != fhinput->fh_OrigBuf) {
 178                 D(bug("%s: Not injecting to fh %p - nonstandard buffering detected\n", __func__, fhinput));
 179                 return FALSE;
 180             }
 181         }
 182     }
 183
 184
 185     /* Deallocate old filehandle's buffer (if any) */
 186     vbuf_free(fhinput);
 187
 188     /* Must be always buffered or EndCLI won't work */
 189     buf = vbuf_alloc(fhinput, NULL, size);
 190     if (buf)
 191     {
 192         D(bug("[vbuf_inject] Handle 0x%p, buffer 0x%p, injecting string: %s, size: %u\n", fh, buf, argptr, size));
 193
 194         /* ugly hack */
 195         fhinput->fh_Pos = 0;
 196         if (size > 0)
 197         {
 198             CopyMem(argptr, buf, size);
 199             DB2(bug("[vbuf_inject] Buffer contents:\n"); hexdump(buf, (IPTR)buf, size));
 200         }
 201         fhinput->fh_End = size;
 202     }
 203
 204     return TRUE;
 205 }