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) 1992,93,94,96,97,2000 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 Lesser General Public
    8:    License as published by the Free Software Foundation; either
    9:    version 2.1 of the 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:    Lesser General Public License for more details.
   15: 
   16:    You should have received a copy of the GNU Lesser General Public
   17:    License along with the GNU C Library; if not, write to the Free
   18:    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   19:    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: 
   28: static ssize_t
   29: devstream_write (void *cookie, const char *buffer, size_t n)
   30: {
   31:   const device_t dev = (device_t) cookie;
   32: 
   33:   int write_some (const char *p, size_t to_write)
   34:     {
   35:       kern_return_t err;
   36:       int wrote;
   37:       int thiswrite;
   38: 
   39:       while (to_write > 0)
   40:         {
   41:           thiswrite = to_write;
   42:           if (thiswrite > IO_INBAND_MAX)
   43:             thiswrite = IO_INBAND_MAX;
   44: 
   45:           if (err = device_write_inband (dev, 0, 0, p, thiswrite, &wrote))
   46:             {
   47:               errno = err;
   48:               return 0;
   49:             }
   50:           p += wrote;
   51:           to_write -= wrote;
   52:         }
   53:       return 1;
   54:     }
   55:   int write_crlf (void)
   56:     {
   57:       static const char crlf[] = "\r\n";
   58:       return write_some (crlf, 2);
   59:     }
   60: 
   61:   /* Search for newlines (LFs) in the buffer.  */
   62: 
   63:   const char *start = buffer, *p;
   64:   while ((p = memchr (start, '\n', n)) != NULL)
   65:     {
   66:       /* Found one.  Write out through the preceding character,
   67:          and then write a CR/LF pair.  */
   68: 
   69:       if ((p > start && !write_some (start, p - start))
   70:           || !write_crlf ())
   71:         return (start - buffer) ?: -1;
   72: 
   73:       n -= p + 1 - start;
   74:       start = p + 1;
   75:     }
   76: 
   77:   /* Write the remainder of the buffer.  */
   78:   if (write_some (start, n))
   79:     start += n;
   80:   return (start - buffer) ?: -1;
   81: }
   82: 
   83: static ssize_t
   84: devstream_read (void *cookie, char *buffer, size_t to_read)
   85: {
   86:   const device_t dev = (device_t) cookie;
   87: 
   88:   kern_return_t err;
   89:   mach_msg_type_number_t nread = to_read;
   90: 
   91:   err = device_read_inband (dev, 0, 0, to_read, buffer, &nread);
   92:   if (err)
   93:     {
   94:       errno = err;
   95:       return -1;
   96:     }
   97: 
   98:   /* Translate CR to LF.  */
   99:   {
  100:     char *p;
  101:     for (p = memchr (buffer, '\r', nread); p;
  102:          p = memchr (p + 1, '\r', (buffer + nread) - (p + 1)))
  103:       *p = '\n';
  104:   }
  105: 
  106:   /* Echo back what we read.  */
  107:   (void) devstream_write (cookie, buffer, nread);
  108: 
  109:   return nread;
  110: }
  111: 
  112: static int
  113: dealloc_ref (void *cookie)
  114: {
  115:   if (mach_port_deallocate (mach_task_self (), (mach_port_t) cookie))
  116:     {
  117:       errno = EINVAL;
  118:       return -1;
  119:     }
  120:   return 0;
  121: }
  122: 
  123: #ifndef USE_IN_LIBIO
  124: #define cookie_io_functions_t __io_functions
  125: #define write __write
  126: #define read __read
  127: #define close __close
  128: #endif
  129: 
  130: FILE *
  131: mach_open_devstream (mach_port_t dev, const char *mode)
  132: {
  133:   FILE *stream;
  134: 
  135:   if (mach_port_mod_refs (mach_task_self (), dev, MACH_PORT_RIGHT_SEND, 1))
  136:     {
  137:       errno = EINVAL;
  138:       return NULL;
  139:     }
  140: 
  141:   stream = fopencookie ((void *) dev, mode,
  142:                         (cookie_io_functions_t) { write: devstream_write,
  143:                                                   read: devstream_read,
  144:                                                   close: dealloc_ref });
  145:   if (stream == NULL)
  146:     {
  147:       mach_port_deallocate (mach_task_self (), dev);
  148:       return NULL;
  149:     }
  150: 
  151:   return stream;
  152: }