glibc/debug/snprintf_chk.c

44 lines
1.4 KiB
C

/* Copyright (C) 1991-2019 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <stdarg.h>
#include <libio/libioP.h>
/* Write formatted output into S, according to the format
string FORMAT, writing no more than MAXLEN characters. */
int
___snprintf_chk (char *s, size_t maxlen, int flag, size_t slen,
const char *format, ...)
{
if (__glibc_unlikely (slen < maxlen))
__chk_fail ();
/* For flag > 0 (i.e. __USE_FORTIFY_LEVEL > 1) request that %n
can only come from read-only format strings. */
unsigned int mode = (flag > 0) ? PRINTF_FORTIFY : 0;
va_list ap;
int ret;
va_start (ap, format);
ret = __vsnprintf_internal (s, maxlen, format, ap, mode);
va_end (ap);
return ret;
}
ldbl_strong_alias (___snprintf_chk, __snprintf_chk)