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       while (to_write > 0)
 151         {
 152           if (err = device_write_inband ((device_t) f->__cookie, 0,
 153                                          f->__target, p, to_write, &wrote))
 154             {
 155               errno = err;
 156               f->__error = 1;
 157               break;
 158             }
 159           p += wrote;
 160           to_write -= wrote;
 161           f->__target += wrote;
 162         }
 163     }
 164   void write_crlf (void)
 165     {
 166       static const char crlf[] = "\r\n";
 167       write_some (crlf, 2);
 168     }
 169
 170   if (f->__buffer == NULL)
 171     {
 172       /* The stream is unbuffered.  */
 173
 174       if (c == '\n')
 175         write_crlf ();
 176       else if (c != EOF)
 177         {
 178           char cc = (unsigned char) c;
 179           write_some (&cc, 1);
 180         }
 181
 182       return;
 183     }
 184
 185   if (f->__put_limit == f->__buffer)
 186     {
 187       /* Prime the stream for writing.  */
 188       f->__put_limit = f->__buffer + f->__bufsize;
 189       f->__bufp = f->__buffer;
 190       if (c != EOF)
 191         {
 192           *f->__bufp++ = (unsigned char) c;
 193           c = EOF;
 194         }
 195     }
 196
 197   {
 198     /* Search for newlines (LFs) in the buffer.  */
 199
 200     char *start = f->__buffer, *p = start;
 201
 202     while (!ferror (f) && (p = memchr (p, '\n', f->__bufp - start)))
 203       {
 204         /* Found one.  Replace it with a CR and write out through that CR.  */
 205
 206         *p = '\r';
 207         write_some (start, p + 1 - start);
 208
 209         /* Change it back to an LF; the next iteration will write it out
 210            first thing.  Start the next searching iteration one char later.  */
 211
 212         start = p;
 213         *p++ = '\n';
 214       }
 215
 216     /* Write the remainder of the buffer.  */
 217
 218     if (!ferror (f))
 219       write_some (start, f->__bufp - start);
 220   }
 221
 222   f->__bufp = f->__buffer;
 223
 224   if (c != EOF && !ferror (f))
 225     {
 226       if (f->__linebuf && (unsigned char) c == '\n')
 227         write_crlf ();
 228       else
 229         *f->__bufp++ = (unsigned char) c;
 230     }
 231 }
 232
 233 static int
 234 dealloc_ref (void *cookie)
 235 {
 236   if (mach_port_deallocate (mach_task_self (), (mach_port_t) cookie))
 237     {
 238       errno = EINVAL;
 239       return -1;
 240     }
 241   return 0;
 242 }
 243
 244
 245 FILE *
 246 mach_open_devstream (mach_port_t dev, const char *mode)
 247 {
 248   FILE *stream;
 249
 250   if (mach_port_mod_refs (mach_task_self (), dev, MACH_PORT_RIGHT_SEND, 1))
 251     {
 252       errno = EINVAL;
 253       return NULL;
 254     }
 255
 256   stream = fopencookie ((void *) dev, mode, __default_io_functions);
 257   if (stream == NULL)
 258     {
 259       mach_port_deallocate (mach_task_self (), dev);
 260       return NULL;
 261     }
 262
 263   stream->__room_funcs.__input = input;
 264   stream->__room_funcs.__output = output;
 265   stream->__io_funcs.__close = dealloc_ref;
 266   stream->__io_funcs.__seek = NULL; /* Cannot seek.  */
 267   stream->__io_funcs.__fileno = NULL; /* No corresponding POSIX.1 fd.  */
 268   stream->__seen = 1;
 269
 270   return stream;
 271 }