libc/stdio/fopencookie.c

   1 /* Copyright (C) 2004       Manuel Novoa III    <mjn3@codepoet.org>
   2  *
   3  * GNU Library General Public License (LGPL) version 2 or later.
   4  *
   5  * Dedicated to Toni.  See uClibc/DEDICATION.mjn3 for details.
   6  */
   7
   8 #include <features.h>
   9
  10 #ifdef __USE_GNU
  11 #include "_stdio.h"
  12
  13 #ifndef __UCLIBC_HAS_GLIBC_CUSTOM_STREAMS__
  14 #error no custom streams!
  15 #endif
  16
  17 /* NOTE: GLIBC difference!!! -- fopencookie
  18  * According to the info pages, glibc allows seeking within buffers even if
  19  * no seek function is supplied.  We don't. */
  20
  21 /* NOTE: GLIBC difference!!! -- fopencookie
  22  * When compiled without large file support, the offset pointer for the
  23  * cookie_seek function is off_t * and not off64_t * as for glibc. */
  24
  25 /* NOTE: GLIBC difference!!! -- fopencookie (bcc only)
  26  * Since bcc doesn't support passing of structs, we define fopencookie as a
  27  * macro in terms of _fopencookie which takes a struct * for the io functions
  28  * instead.
  29  */
  30
  31 /* Currently no real reentrancy issues other than a possible double close(). */
  32
  33 #ifndef __BCC__
  34 FILE *fopencookie(void * __restrict cookie, const char * __restrict mode,
  35                                   cookie_io_functions_t io_functions)
  36 #else
  37 FILE *_fopencookie(void * __restrict cookie, const char * __restrict mode,
  38                                    register cookie_io_functions_t *io_functions)
  39 #endif
  40 {
  41         FILE *stream;
  42         _IO_cookie_file_t *new_f;
  43
  44         new_f = malloc(sizeof(_IO_cookie_file_t));
  45         if (new_f == NULL) {
  46                 return NULL;
  47         }
  48         new_f->__fp.__modeflags = __FLAG_FREEFILE;
  49 #ifdef __STDIO_BUFFERS
  50         new_f->__fp.__bufstart = NULL; /* We allocate a buffer below. */
  51 #endif
  52 #ifdef __UCLIBC_HAS_THREADS__
  53         /* We only initialize the mutex in the non-freopen case. */
  54         STDIO_INIT_MUTEX(new_f->__fp.__lock);
  55 #endif
  56         /* Fake an fdopen guaranteed to pass the _stdio_fopen basic agreement
  57          * check without an fcntl call. */
  58         stream = _stdio_fopen(((intptr_t)(INT_MAX-1)), mode, &new_f->__fp, INT_MAX);
  59         if (stream) {
  60                 stream->__filedes = __STDIO_STREAM_GLIBC_CUSTOM_FILEDES;
  61 #ifndef __BCC__
  62                 new_f->__gcs = io_functions;
  63 #else
  64                 new_f->__gcs.read  = io_functions->read;
  65                 new_f->__gcs.write = io_functions->write;
  66                 new_f->__gcs.seek  = io_functions->seek;
  67                 new_f->__gcs.close = io_functions->close;
  68 #endif
  69                 new_f->__cookie = cookie;
  70
  71                 __STDIO_STREAM_VALIDATE(stream);
  72         }
  73
  74         return stream;
  75 }
  76 #ifndef __BCC__
  77 libc_hidden_def(fopencookie)
  78 #endif
  79 #endif