hurd/fopenport.c

   1 /* Copyright (C) 1994,95,97,2000,01 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   off_t res;
  74   error_t error;
  75
  76   /* XXX We don't really support large files on the Hurd.  So if POS
  77      doesn't fit in an `off_t', we'll return `-1' and set errno.  EOVERFLOW
  78      probably isn't the right error value, but seems appropriate here.  */
  79   if ((off_t) *pos != *pos)
  80     {
  81       __set_errno (EOVERFLOW);
  82       return -1;
  83     }
  84
  85   error = __io_seek ((file_t) cookie, *pos, whence, &res);
  86   if (error)
  87     return __hurd_fail (error);
  88   *pos = res;
  89   return 0;
  90 }
  91
  92 /* Close the file associated with COOKIE.
  93    Return 0 for success or -1 for failure.  */
  94 static int
  95 closeio (void *cookie)
  96 {
  97   error_t error = __mach_port_deallocate (__mach_task_self (),
  98                                           (mach_port_t) cookie);
  99   if (error)
 100     return __hurd_fail (error);
 101   return 0;
 102 }
 103
 104 #ifndef USE_IN_LIBIO
 105 #define cookie_io_functions_t __io_functions
 106 #endif
 107 static const cookie_io_functions_t funcsio =
 108 { readio, writeio, seekio, closeio };
 109 \f
 110
 111 /* Open a stream on PORT.  MODE is as for fopen.  */
 112
 113 FILE *
 114 fopenport (mach_port_t port, const char *mode)
 115 {
 116   int pflags;
 117   int needflags;
 118   error_t err;
 119
 120   const char *m = mode;
 121
 122   switch (*m++)
 123     {
 124     case 'r':
 125       needflags = O_READ;
 126       break;
 127     case 'w':
 128       needflags = O_WRITE;
 129       break;
 130     case 'a':
 131       needflags = O_WRITE|O_APPEND;
 132       break;
 133     default:
 134       return NULL;
 135   }
 136   if (m[0] == '+' || (m[0] == 'b' && m[1] == '+'))
 137     needflags |= O_RDWR;
 138
 139   /* Verify the PORT is valid allows the access MODE specifies.  */
 140
 141   if (err = __io_get_openmodes (port, &pflags))
 142     return __hurd_fail (err), NULL;
 143
 144   /* Check the access mode.  */
 145   if ((pflags & needflags) != needflags)
 146     {
 147       errno = EBADF;
 148       return NULL;
 149     }
 150
 151   return fopencookie ((void *) port, mode, funcsio);
 152 }