mach/devstream.c

   1 /* stdio on a Mach device port.
   2    Translates \n to \r\n on output, echos and translates \r to \n on input.
   3    Copyright (C) 1992, 1993, 1994, 1996, 1997 Free Software Foundation, Inc.
   4    This file is part of the GNU C Library.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Library General Public License as
   8    published by the Free Software Foundation; either version 2 of the
   9    License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Library General Public License for more details.
  15
  16    You should have received a copy of the GNU Library General Public
  17    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  18    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  19    Boston, MA 02111-1307, USA.  */
  20
  21 #include <stdio.h>
  22 #include <mach.h>
  23 #include <device/device.h>
  24 #include <errno.h>
  25 #include <string.h>
  26
  27 static int
  28 input (FILE *f)
  29 {
  30   kern_return_t err;
  31   char *buffer;
  32   size_t to_read;
  33   mach_msg_type_number_t nread;
  34   char c;
  35
  36   if (f->__buffer == NULL)
  37     {
  38       buffer = &c;
  39       to_read = 1;
  40     }
  41   else
  42     {
  43       buffer = f->__buffer;
  44       to_read = f->__bufsize;
  45     }
  46
  47   f->__eof = 0;
  48
  49   nread = to_read;
  50   err = device_read_inband ((device_t) f->__cookie, 0, f->__target,
  51                             to_read, buffer, &nread);
  52
  53   if (err)
  54     {
  55       f->__error = 1;
  56       f->__bufp = f->__get_limit = f->__put_limit = f->__buffer;
  57       errno = err;
  58       return EOF;
  59     }
  60
  61   /* Echo it back.  */
  62   err = device_write_inband ((device_t) f->__cookie, 0, f->__target,
  63                              buffer, nread, (int *) &to_read);
  64
  65   /* Translate LF to CR.  */
  66   {
  67     char *p;
  68     for (p = memchr (buffer, '\r', nread); p;
  69          p = memchr (p + 1, '\r', (buffer + nread) - (p + 1)))
  70       *p = '\n';
  71   }
  72
  73   if (f->__buffer == NULL)
  74     return (unsigned char) c;
  75
  76   f->__get_limit = f->__buffer + nread;
  77   f->__bufp = f->__buffer;
  78   f->__put_limit = f->__buffer + (f->__mode.__write ? f->__bufsize : 0);
  79   return (unsigned char) *f->__bufp++;
  80 }
  81
  82
  83 #if 0
  84 static void
  85 output (FILE *f, int c)
  86 {
  87   inline void write_some (const char *p, size_t to_write)
  88     {
  89       kern_return_t err;
  90       int wrote;
  91       while (to_write > 0)
  92         {
  93           if (err = device_write ((device_t) f->__cookie, 0,
  94                                   f->__target, (char *)p,
  95                                   to_write, &wrote))
  96             {
  97               errno = err;
  98               f->__error = 1;
  99               break;
 100             }
 101           p += wrote;
 102           to_write -= wrote;
 103           f->__target += wrote;
 104         }
 105     }
 106
 107   if (f->__buffer != NULL)
 108     {
 109       if (f->__put_limit == f->__buffer)
 110         {
 111           /* Prime the stream for writing.  */
 112           f->__put_limit = f->__buffer + f->__bufsize;
 113           f->__bufp = f->__buffer;
 114           if (c != EOF)
 115             {
 116               *f->__bufp++ = (unsigned char) c;
 117               c = EOF;
 118             }
 119         }
 120
 121
 122       /* Write out the buffer.  */
 123
 124       write_some (f->__buffer, f->__bufp - f->__buffer);
 125
 126       f->__bufp = f->__buffer;
 127     }
 128
 129   if (c != EOF && !ferror (f))
 130     {
 131       if (f->__linebuf && (unsigned char) c == '\n')
 132         {
 133           static const char nl = '\n';
 134           write_some (&nl, 1);
 135         }
 136       else
 137         *f->__bufp++ = (unsigned char) c;
 138     }
 139 }
 140 #endif
 141
 142
 143 static void
 144 output (FILE *f, int c)
 145 {
 146   void write_some (const char *p, size_t to_write)
 147     {
 148       kern_return_t err;
 149       int wrote;
 150       int thiswrite;
 151
 152       while (to_write > 0)
 153         {
 154           thiswrite = to_write;
 155           if (thiswrite > IO_INBAND_MAX)
 156             thiswrite = IO_INBAND_MAX;
 157
 158           if (err = device_write_inband ((device_t) f->__cookie, 0,
 159                                          f->__target, p, thiswrite, &wrote))
 160             {
 161               errno = err;
 162               f->__error = 1;
 163               break;
 164             }
 165           p += wrote;
 166           to_write -= wrote;
 167           f->__target += wrote;
 168         }
 169     }
 170   void write_crlf (void)
 171     {
 172       static const char crlf[] = "\r\n";
 173       write_some (crlf, 2);
 174     }
 175
 176   if (f->__buffer == NULL)
 177     {
 178       /* The stream is unbuffered.  */
 179
 180       if (c == '\n')
 181         write_crlf ();
 182       else if (c != EOF)
 183         {
 184           char cc = (unsigned char) c;
 185           write_some (&cc, 1);
 186         }
 187
 188       return;
 189     }
 190
 191   if (f->__put_limit == f->__buffer)
 192     {
 193       /* Prime the stream for writing.  */
 194       f->__put_limit = f->__buffer + f->__bufsize;
 195       f->__bufp = f->__buffer;
 196       if (c != EOF)
 197         {
 198           *f->__bufp++ = (unsigned char) c;
 199           c = EOF;
 200         }
 201     }
 202
 203   {
 204     /* Search for newlines (LFs) in the buffer.  */
 205
 206     char *start = f->__buffer, *p = start;
 207
 208     while (!ferror (f) && (p = memchr (p, '\n', f->__bufp - start)))
 209       {
 210         /* Found one.  Replace it with a CR and write out through that CR.  */
 211
 212         *p = '\r';
 213         write_some (start, p + 1 - start);
 214
 215         /* Change it back to an LF; the next iteration will write it out
 216            first thing.  Start the next searching iteration one char later.  */
 217
 218         start = p;
 219         *p++ = '\n';
 220       }
 221
 222     /* Write the remainder of the buffer.  */
 223
 224     if (!ferror (f))
 225       write_some (start, f->__bufp - start);
 226   }
 227
 228   f->__bufp = f->__buffer;
 229
 230   if (c != EOF && !ferror (f))
 231     {
 232       if (f->__linebuf && (unsigned char) c == '\n')
 233         write_crlf ();
 234       else
 235         *f->__bufp++ = (unsigned char) c;
 236     }
 237 }
 238
 239 static int
 240 dealloc_ref (void *cookie)
 241 {
 242   if (mach_port_deallocate (mach_task_self (), (mach_port_t) cookie))
 243     {
 244       errno = EINVAL;
 245       return -1;
 246     }
 247   return 0;
 248 }
 249
 250
 251 FILE *
 252 mach_open_devstream (mach_port_t dev, const char *mode)
 253 {
 254   FILE *stream;
 255
 256   if (mach_port_mod_refs (mach_task_self (), dev, MACH_PORT_RIGHT_SEND, 1))
 257     {
 258       errno = EINVAL;
 259       return NULL;
 260     }
 261
 262   stream = fopencookie ((void *) dev, mode, __default_io_functions);
 263   if (stream == NULL)
 264     {
 265       mach_port_deallocate (mach_task_self (), dev);
 266       return NULL;
 267     }
 268
 269   stream->__room_funcs.__input = input;
 270   stream->__room_funcs.__output = output;
 271   stream->__io_funcs.__close = dealloc_ref;
 272   stream->__io_funcs.__seek = NULL; /* Cannot seek.  */
 273   stream->__io_funcs.__fileno = NULL; /* No corresponding POSIX.1 fd.  */
 274   stream->__seen = 1;
 275
 276   return stream;
 277 }