1: /* Copyright (C) 1991, 1995, 1997, 1998, 2004, 2006
    2:    Free Software Foundation, Inc.
    3:    This file is part of the GNU C Library.
    4: 
    5:    The GNU C Library is free software; you can redistribute it and/or
    6:    modify it under the terms of the GNU Lesser General Public
    7:    License as published by the Free Software Foundation; either
    8:    version 2.1 of the License, or (at your option) any later version.
    9: 
   10:    The GNU C Library is distributed in the hope that it will be useful,
   11:    but WITHOUT ANY WARRANTY; without even the implied warranty of
   12:    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   13:    Lesser General Public License for more details.
   14: 
   15:    You should have received a copy of the GNU Lesser General Public
   16:    License along with the GNU C Library; if not, write to the Free
   17:    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   18:    02111-1307 USA.  */
   19: 
   20: #include <stdarg.h>
   21: #include <stdio.h>
   22: #include "../libio/libioP.h"
   23: #include "../libio/strfile.h"
   24: 
   25: extern const struct _IO_jump_t _IO_strn_jumps attribute_hidden;
   26: 
   27: /* Write formatted output into S, according to the format
   28:    string FORMAT, writing no more than MAXLEN characters.  */
   29: /* VARARGS5 */
   30: int
   31: ___vsnprintf_chk (char *s, size_t maxlen, int flags, size_t slen,
   32:                   const char *format, va_list args)
   33: {
   34:   /* XXX Maybe for less strict version do not fail immediately.
   35:      Though, maxlen is supposed to be the size of buffer pointed
   36:      to by s, so a conforming program can't pass such maxlen
   37:      to *snprintf.  */
   38:   if (__builtin_expect (slen < maxlen, 0))
   39:     __chk_fail ();
   40: 
   41:   _IO_strnfile sf;
   42:   int ret;
   43: #ifdef _IO_MTSAFE_IO
   44:   sf.f._sbf._f._lock = NULL;
   45: #endif
   46: 
   47:   /* We need to handle the special case where MAXLEN is 0.  Use the
   48:      overflow buffer right from the start.  */
   49:   if (maxlen == 0)
   50:     {
   51:       s = sf.overflow_buf;
   52:       maxlen = sizeof (sf.overflow_buf);
   53:     }
   54: 
   55:   _IO_no_init (&sf.f._sbf._f, _IO_USER_LOCK, -1, NULL, NULL);
   56:   _IO_JUMPS ((struct _IO_FILE_plus *) &sf.f._sbf) = &_IO_strn_jumps;
   57:   s[0] = '\0';
   58: 
   59:   /* For flags > 0 (i.e. __USE_FORTIFY_LEVEL > 1) request that %n
   60:      can only come from read-only format strings.  */
   61:   if (flags > 0)
   62:     sf.f._sbf._f._flags2 |= _IO_FLAGS2_FORTIFY;
   63: 
   64:   _IO_str_init_static_internal (&sf.f, s, maxlen - 1, s);
   65:   ret = INTUSE(_IO_vfprintf) ((_IO_FILE *) &sf.f._sbf, format, args);
   66: 
   67:   if (sf.f._sbf._f._IO_buf_base != sf.overflow_buf)
   68:     *sf.f._sbf._f._IO_write_ptr = '\0';
   69:   return ret;
   70: }
   71: ldbl_hidden_def (___vsnprintf_chk, __vsnprintf_chk)
   72: ldbl_strong_alias (___vsnprintf_chk, __vsnprintf_chk)