libio/iofopncook.c

   1 /* Copyright (C) 1993-2015 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    <http://www.gnu.org/licenses/>.
  17
  18    As a special exception, if you link the code in this file with
  19    files compiled with a GNU compiler to produce an executable,
  20    that does not cause the resulting executable to be covered by
  21    the GNU Lesser General Public License.  This exception does not
  22    however invalidate any other reasons why the executable file
  23    might be covered by the GNU Lesser General Public License.
  24    This exception applies to code released by its copyright holders
  25    in files containing the exception.  */
  26
  27 #include <libioP.h>
  28 #include <stdio.h>
  29 #include <stdlib.h>
  30 #include <shlib-compat.h>
  31
  32 /* Prototyped for local functions.  */
  33 static _IO_ssize_t _IO_cookie_read (_IO_FILE* fp, void* buf,
  34                                     _IO_ssize_t size);
  35 static _IO_ssize_t _IO_cookie_write (_IO_FILE* fp,
  36                                      const void* buf, _IO_ssize_t size);
  37 static _IO_off64_t _IO_cookie_seek (_IO_FILE *fp, _IO_off64_t offset, int dir);
  38 static _IO_off64_t _IO_cookie_seekoff (_IO_FILE *fp, _IO_off64_t offset,
  39                                        int dir, int mode);
  40 static int _IO_cookie_close (_IO_FILE* fp);
  41
  42 static _IO_ssize_t
  43 _IO_cookie_read (fp, buf, size)
  44      _IO_FILE *fp;
  45      void *buf;
  46      _IO_ssize_t size;
  47 {
  48   struct _IO_cookie_file *cfile = (struct _IO_cookie_file *) fp;
  49
  50   if (cfile->__io_functions.read == NULL)
  51     return -1;
  52
  53   return cfile->__io_functions.read (cfile->__cookie, buf, size);
  54 }
  55
  56 static _IO_ssize_t
  57 _IO_cookie_write (fp, buf, size)
  58      _IO_FILE *fp;
  59      const void *buf;
  60      _IO_ssize_t size;
  61 {
  62   struct _IO_cookie_file *cfile = (struct _IO_cookie_file *) fp;
  63
  64   if (cfile->__io_functions.write == NULL)
  65     {
  66       fp->_flags |= _IO_ERR_SEEN;
  67       return 0;
  68     }
  69
  70   _IO_ssize_t n = cfile->__io_functions.write (cfile->__cookie, buf, size);
  71   if (n < size)
  72     fp->_flags |= _IO_ERR_SEEN;
  73
  74   return n;
  75 }
  76
  77 static _IO_off64_t
  78 _IO_cookie_seek (fp, offset, dir)
  79      _IO_FILE *fp;
  80      _IO_off64_t offset;
  81      int dir;
  82 {
  83   struct _IO_cookie_file *cfile = (struct _IO_cookie_file *) fp;
  84
  85   return ((cfile->__io_functions.seek == NULL
  86            || (cfile->__io_functions.seek (cfile->__cookie, &offset, dir)
  87                == -1)
  88            || offset == (_IO_off64_t) -1)
  89           ? _IO_pos_BAD : offset);
  90 }
  91
  92 static int
  93 _IO_cookie_close (fp)
  94      _IO_FILE *fp;
  95 {
  96   struct _IO_cookie_file *cfile = (struct _IO_cookie_file *) fp;
  97
  98   if (cfile->__io_functions.close == NULL)
  99     return 0;
 100
 101   return cfile->__io_functions.close (cfile->__cookie);
 102 }
 103
 104
 105 static _IO_off64_t
 106 _IO_cookie_seekoff (fp, offset, dir, mode)
 107      _IO_FILE *fp;
 108      _IO_off64_t offset;
 109      int dir;
 110      int mode;
 111 {
 112   /* We must force the fileops code to always use seek to determine
 113      the position.  */
 114   fp->_offset = _IO_pos_BAD;
 115   return _IO_file_seekoff (fp, offset, dir, mode);
 116 }
 117
 118
 119 static const struct _IO_jump_t _IO_cookie_jumps = {
 120   JUMP_INIT_DUMMY,
 121   JUMP_INIT(finish, _IO_file_finish),
 122   JUMP_INIT(overflow, _IO_file_overflow),
 123   JUMP_INIT(underflow, _IO_file_underflow),
 124   JUMP_INIT(uflow, _IO_default_uflow),
 125   JUMP_INIT(pbackfail, _IO_default_pbackfail),
 126   JUMP_INIT(xsputn, _IO_file_xsputn),
 127   JUMP_INIT(xsgetn, _IO_default_xsgetn),
 128   JUMP_INIT(seekoff, _IO_cookie_seekoff),
 129   JUMP_INIT(seekpos, _IO_default_seekpos),
 130   JUMP_INIT(setbuf, _IO_file_setbuf),
 131   JUMP_INIT(sync, _IO_file_sync),
 132   JUMP_INIT(doallocate, _IO_file_doallocate),
 133   JUMP_INIT(read, _IO_cookie_read),
 134   JUMP_INIT(write, _IO_cookie_write),
 135   JUMP_INIT(seek, _IO_cookie_seek),
 136   JUMP_INIT(close, _IO_cookie_close),
 137   JUMP_INIT(stat, _IO_default_stat),
 138   JUMP_INIT(showmanyc, _IO_default_showmanyc),
 139   JUMP_INIT(imbue, _IO_default_imbue),
 140 };
 141
 142
 143 void
 144 _IO_cookie_init (struct _IO_cookie_file *cfile, int read_write,
 145                  void *cookie, _IO_cookie_io_functions_t io_functions)
 146 {
 147   _IO_init (&cfile->__fp.file, 0);
 148   _IO_JUMPS (&cfile->__fp) = &_IO_cookie_jumps;
 149
 150   cfile->__cookie = cookie;
 151   cfile->__io_functions = io_functions;
 152
 153   _IO_file_init (&cfile->__fp);
 154
 155   _IO_mask_flags (&cfile->__fp.file, read_write,
 156                   _IO_NO_READS+_IO_NO_WRITES+_IO_IS_APPENDING);
 157
 158   /* We use a negative number different from -1 for _fileno to mark that
 159      this special stream is not associated with a real file, but still has
 160      to be treated as such.  */
 161   cfile->__fp.file._fileno = -2;
 162 }
 163
 164
 165 _IO_FILE *
 166 _IO_fopencookie (cookie, mode, io_functions)
 167      void *cookie;
 168      const char *mode;
 169      _IO_cookie_io_functions_t io_functions;
 170 {
 171   int read_write;
 172   struct locked_FILE
 173   {
 174     struct _IO_cookie_file cfile;
 175 #ifdef _IO_MTSAFE_IO
 176     _IO_lock_t lock;
 177 #endif
 178   } *new_f;
 179
 180   switch (*mode++)
 181     {
 182     case 'r':
 183       read_write = _IO_NO_WRITES;
 184       break;
 185     case 'w':
 186       read_write = _IO_NO_READS;
 187       break;
 188     case 'a':
 189       read_write = _IO_NO_READS|_IO_IS_APPENDING;
 190       break;
 191     default:
 192       return NULL;
 193   }
 194   if (mode[0] == '+' || (mode[0] == 'b' && mode[1] == '+'))
 195     read_write &= _IO_IS_APPENDING;
 196
 197   new_f = (struct locked_FILE *) malloc (sizeof (struct locked_FILE));
 198   if (new_f == NULL)
 199     return NULL;
 200 #ifdef _IO_MTSAFE_IO
 201   new_f->cfile.__fp.file._lock = &new_f->lock;
 202 #endif
 203
 204   _IO_cookie_init (&new_f->cfile, read_write, cookie, io_functions);
 205
 206   return (_IO_FILE *) &new_f->cfile.__fp;
 207 }
 208
 209 versioned_symbol (libc, _IO_fopencookie, fopencookie, GLIBC_2_2);
 210
 211 #if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_2)
 212
 213 static _IO_off64_t _IO_old_cookie_seek (_IO_FILE *fp, _IO_off64_t offset,
 214                                         int dir);
 215 _IO_FILE * _IO_old_fopencookie (void *cookie, const char *mode,
 216                                 _IO_cookie_io_functions_t io_functions);
 217
 218 static _IO_off64_t
 219 attribute_compat_text_section
 220 _IO_old_cookie_seek (fp, offset, dir)
 221      _IO_FILE *fp;
 222      _IO_off64_t offset;
 223      int dir;
 224 {
 225   struct _IO_cookie_file *cfile = (struct _IO_cookie_file *) fp;
 226   int (*seek) (_IO_FILE *, _IO_off_t, int);
 227   int ret;
 228
 229   seek = (int (*)(_IO_FILE *, _IO_off_t, int)) cfile->__io_functions.seek;
 230   if (seek == NULL)
 231     return _IO_pos_BAD;
 232
 233   ret = seek (cfile->__cookie, offset, dir);
 234
 235   return (ret == -1) ? _IO_pos_BAD : ret;
 236 }
 237
 238 static const struct _IO_jump_t _IO_old_cookie_jumps = {
 239   JUMP_INIT_DUMMY,
 240   JUMP_INIT(finish, _IO_file_finish),
 241   JUMP_INIT(overflow, _IO_file_overflow),
 242   JUMP_INIT(underflow, _IO_file_underflow),
 243   JUMP_INIT(uflow, _IO_default_uflow),
 244   JUMP_INIT(pbackfail, _IO_default_pbackfail),
 245   JUMP_INIT(xsputn, _IO_file_xsputn),
 246   JUMP_INIT(xsgetn, _IO_default_xsgetn),
 247   JUMP_INIT(seekoff, _IO_cookie_seekoff),
 248   JUMP_INIT(seekpos, _IO_default_seekpos),
 249   JUMP_INIT(setbuf, _IO_file_setbuf),
 250   JUMP_INIT(sync, _IO_file_sync),
 251   JUMP_INIT(doallocate, _IO_file_doallocate),
 252   JUMP_INIT(read, _IO_cookie_read),
 253   JUMP_INIT(write, _IO_cookie_write),
 254   JUMP_INIT(seek, _IO_old_cookie_seek),
 255   JUMP_INIT(close, _IO_cookie_close),
 256   JUMP_INIT(stat, _IO_default_stat),
 257   JUMP_INIT(showmanyc, _IO_default_showmanyc),
 258   JUMP_INIT(imbue, _IO_default_imbue),
 259 };
 260
 261 _IO_FILE *
 262 attribute_compat_text_section
 263 _IO_old_fopencookie (cookie, mode, io_functions)
 264      void *cookie;
 265      const char *mode;
 266      _IO_cookie_io_functions_t io_functions;
 267 {
 268   _IO_FILE *ret;
 269
 270   ret = _IO_fopencookie (cookie, mode, io_functions);
 271   if (ret != NULL)
 272     _IO_JUMPS_FILE_plus (ret) = &_IO_old_cookie_jumps;
 273
 274   return ret;
 275 }
 276
 277 compat_symbol (libc, _IO_old_fopencookie, fopencookie, GLIBC_2_0);
 278
 279 #endif