hurd/fopenport.c

   1 /* Copyright (C) 1994-2021 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, see
  16    <https://www.gnu.org/licenses/>.  */
  17
  18 #include <hurd.h>
  19 #include <stdio.h>
  20 #include <fcntl.h>
  21 #include <string.h>
  22
  23 /* Read up to N chars into BUF from COOKIE.
  24    Return how many chars were read, 0 for EOF or -1 for error.  */
  25 static ssize_t
  26 readio (void *cookie, char *buf, size_t n)
  27 {
  28   mach_msg_type_number_t nread;
  29   error_t err;
  30   char *bufp = buf;
  31
  32   nread = n;
  33   if (err = __io_read ((io_t) cookie, &bufp, &nread, -1, n))
  34     return __hurd_fail (err);
  35
  36   if (bufp != buf)
  37     {
  38       memcpy (buf, bufp, nread);
  39       __vm_deallocate (__mach_task_self (),
  40                        (vm_address_t) bufp, (vm_size_t) nread);
  41     }
  42
  43   return nread;
  44 }
  45
  46 /* Write up to N chars from BUF to COOKIE.
  47    Return how many chars were written or -1 for error.  */
  48 static ssize_t
  49 writeio (void *cookie, const char *buf, size_t n)
  50 {
  51   mach_msg_type_number_t wrote;
  52   error_t err;
  53
  54   if (err = __io_write ((io_t) cookie, buf, n, -1, &wrote))
  55     return __hurd_fail (err);
  56
  57   return wrote;
  58 }
  59
  60 /* Move COOKIE's file position *POS bytes, according to WHENCE.
  61    The current file position is stored in *POS.
  62    Returns zero if successful, nonzero if not.  */
  63 static int
  64 seekio (void *cookie,
  65         off64_t *pos,
  66         int whence)
  67 {
  68   error_t err = __io_seek ((file_t) cookie, *pos, whence, pos);
  69   return err ? __hurd_fail (err) : 0;
  70 }
  71
  72 /* Close the file associated with COOKIE.
  73    Return 0 for success or -1 for failure.  */
  74 static int
  75 closeio (void *cookie)
  76 {
  77   error_t error = __mach_port_deallocate (__mach_task_self (),
  78                                           (mach_port_t) cookie);
  79   if (error)
  80     return __hurd_fail (error);
  81   return 0;
  82 }
  83
  84 #include "../libio/libioP.h"
  85 #define fopencookie _IO_fopencookie
  86 static const cookie_io_functions_t funcsio =
  87 { readio, writeio, seekio, closeio };
  88 \f
  89
  90 /* Open a stream on PORT.  MODE is as for fopen.  */
  91
  92 FILE *
  93 __fopenport (mach_port_t port, const char *mode)
  94 {
  95   int pflags;
  96   int needflags;
  97   error_t err;
  98
  99   const char *m = mode;
 100
 101   switch (*m++)
 102     {
 103     case 'r':
 104       needflags = O_READ;
 105       break;
 106     case 'w':
 107       needflags = O_WRITE;
 108       break;
 109     case 'a':
 110       needflags = O_WRITE|O_APPEND;
 111       break;
 112     default:
 113       return NULL;
 114   }
 115   if (m[0] == '+' || (m[0] == 'b' && m[1] == '+'))
 116     needflags |= O_RDWR;
 117
 118   /* Verify the PORT is valid allows the access MODE specifies.  */
 119
 120   if (err = __io_get_openmodes (port, &pflags))
 121     return __hurd_fail (err), NULL;
 122
 123   /* Check the access mode.  */
 124   if ((pflags & needflags) != needflags)
 125     {
 126       errno = EBADF;
 127       return NULL;
 128     }
 129
 130   return fopencookie ((void *) port, mode, funcsio);
 131 }
 132 weak_alias (__fopenport, fopenport)