hurd/fopenport.c

   1 /* Copyright (C) 1994,95,97,2000,01,02 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #include <hurd.h>
  20 #include <stdio.h>
  21 #include <fcntl.h>
  22 #include <string.h>
  23
  24 /* Read up to N chars into BUF from COOKIE.
  25    Return how many chars were read, 0 for EOF or -1 for error.  */
  26 static ssize_t
  27 readio (void *cookie, char *buf, size_t n)
  28 {
  29   mach_msg_type_number_t nread;
  30   error_t err;
  31   char *bufp = buf;
  32
  33   nread = n;
  34   if (err = __io_read ((io_t) cookie, &bufp, &nread, -1, n))
  35     return __hurd_fail (err);
  36
  37   if (bufp != buf)
  38     {
  39       memcpy (buf, bufp, nread);
  40       __vm_deallocate (__mach_task_self (),
  41                        (vm_address_t) bufp, (vm_size_t) nread);
  42     }
  43
  44   return nread;
  45 }
  46
  47 /* Write up to N chars from BUF to COOKIE.
  48    Return how many chars were written or -1 for error.  */
  49 static ssize_t
  50 writeio (void *cookie, const char *buf, size_t n)
  51 {
  52   mach_msg_type_number_t wrote;
  53   error_t err;
  54
  55   if (err = __io_write ((io_t) cookie, buf, n, -1, &wrote))
  56     return __hurd_fail (err);
  57
  58   return wrote;
  59 }
  60
  61 /* Move COOKIE's file position *POS bytes, according to WHENCE.
  62    The current file position is stored in *POS.
  63    Returns zero if successful, nonzero if not.  */
  64 static int
  65 seekio (void *cookie,
  66 #ifdef USE_IN_LIBIO
  67         _IO_off64_t *pos,
  68 #else
  69         fpos_t *pos,
  70 #endif
  71         int whence)
  72 {
  73   error_t err = __io_seek ((file_t) cookie, *pos, whence, pos);
  74   return err ? __hurd_fail (err) : 0;
  75 }
  76
  77 /* Close the file associated with COOKIE.
  78    Return 0 for success or -1 for failure.  */
  79 static int
  80 closeio (void *cookie)
  81 {
  82   error_t error = __mach_port_deallocate (__mach_task_self (),
  83                                           (mach_port_t) cookie);
  84   if (error)
  85     return __hurd_fail (error);
  86   return 0;
  87 }
  88
  89 #ifdef USE_IN_LIBIO
  90 #include "../libio/libioP.h"
  91 #define fopencookie _IO_fopencookie
  92 #else
  93 #define cookie_io_functions_t __io_functions
  94 #endif
  95 static const cookie_io_functions_t funcsio =
  96 { readio, writeio, seekio, closeio };
  97 \f
  98
  99 /* Open a stream on PORT.  MODE is as for fopen.  */
 100
 101 FILE *
 102 __fopenport (mach_port_t port, const char *mode)
 103 {
 104   int pflags;
 105   int needflags;
 106   error_t err;
 107
 108   const char *m = mode;
 109
 110   switch (*m++)
 111     {
 112     case 'r':
 113       needflags = O_READ;
 114       break;
 115     case 'w':
 116       needflags = O_WRITE;
 117       break;
 118     case 'a':
 119       needflags = O_WRITE|O_APPEND;
 120       break;
 121     default:
 122       return NULL;
 123   }
 124   if (m[0] == '+' || (m[0] == 'b' && m[1] == '+'))
 125     needflags |= O_RDWR;
 126
 127   /* Verify the PORT is valid allows the access MODE specifies.  */
 128
 129   if (err = __io_get_openmodes (port, &pflags))
 130     return __hurd_fail (err), NULL;
 131
 132   /* Check the access mode.  */
 133   if ((pflags & needflags) != needflags)
 134     {
 135       errno = EBADF;
 136       return NULL;
 137     }
 138
 139   return fopencookie ((void *) port, mode, funcsio);
 140 }
 141 weak_alias (__fopenport, fopenport)