debug/vsprintf_chk.c

   1 /* Copyright (C) 1994, 1997, 1999-2003, 2004 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 <stdarg.h>
  20 #include <stdio.h>
  21 #include "../libio/libioP.h"
  22 #include "../libio/strfile.h"
  23
  24
  25 static int _IO_str_chk_overflow (_IO_FILE *fp, int c) __THROW;
  26
  27 static int
  28 _IO_str_chk_overflow (fp, c)
  29      _IO_FILE *fp;
  30      int c;
  31 {
  32   /* When we come to here this means the user supplied buffer is
  33      filled.  */
  34   __chk_fail ();
  35 }
  36
  37
  38 static const struct _IO_jump_t _IO_str_chk_jumps =
  39 {
  40   JUMP_INIT_DUMMY,
  41   JUMP_INIT(finish, _IO_str_finish),
  42   JUMP_INIT(overflow, _IO_str_chk_overflow),
  43   JUMP_INIT(underflow, INTUSE(_IO_str_underflow)),
  44   JUMP_INIT(uflow, INTUSE(_IO_default_uflow)),
  45   JUMP_INIT(pbackfail, INTUSE(_IO_str_pbackfail)),
  46   JUMP_INIT(xsputn, INTUSE(_IO_default_xsputn)),
  47   JUMP_INIT(xsgetn, INTUSE(_IO_default_xsgetn)),
  48   JUMP_INIT(seekoff, INTUSE(_IO_str_seekoff)),
  49   JUMP_INIT(seekpos, _IO_default_seekpos),
  50   JUMP_INIT(setbuf, _IO_default_setbuf),
  51   JUMP_INIT(sync, _IO_default_sync),
  52   JUMP_INIT(doallocate, INTUSE(_IO_default_doallocate)),
  53   JUMP_INIT(read, _IO_default_read),
  54   JUMP_INIT(write, _IO_default_write),
  55   JUMP_INIT(seek, _IO_default_seek),
  56   JUMP_INIT(close, _IO_default_close),
  57   JUMP_INIT(stat, _IO_default_stat),
  58   JUMP_INIT(showmanyc, _IO_default_showmanyc),
  59   JUMP_INIT(imbue, _IO_default_imbue)
  60 };
  61
  62
  63 int
  64 __vsprintf_chk (char *s, int flags, size_t slen, const char *format,
  65                 va_list args)
  66 {
  67   _IO_strfile f;
  68   int ret;
  69 #ifdef _IO_MTSAFE_IO
  70   f._sbf._f._lock = NULL;
  71 #endif
  72
  73   if (slen == 0)
  74     __chk_fail ();
  75
  76   _IO_no_init (&f._sbf._f, _IO_USER_LOCK, -1, NULL, NULL);
  77   _IO_JUMPS ((struct _IO_FILE_plus *) &f._sbf) = &_IO_str_chk_jumps;
  78   s[0] = '\0';
  79   _IO_str_init_static_internal (&f, s, slen - 1, s);
  80
  81   /* For flags > 0 (i.e. __USE_FORTIFY_LEVEL > 1) request that %n
  82      can only come from read-only format strings.  */
  83   if (flags > 0)
  84     f._sbf._f._flags2 |= _IO_FLAGS2_CHECK_PERCENT_N;
  85
  86   ret = INTUSE(_IO_vfprintf) ((_IO_FILE *) &f._sbf, format, args);
  87
  88   *f._sbf._f._IO_write_ptr = '\0';
  89   return ret;
  90 }
  91 libc_hidden_def (__vsprintf_chk)