1/* Copyright (C) 1991-2016 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#include <stdarg.h>
19#include <wchar.h>
20#include "../libio/libioP.h"
21#include "../libio/strfile.h"
22
23
24/* Write formatted output into S, according to the format
25 string FORMAT, writing no more than MAXLEN characters. */
26/* VARARGS5 */
27int
28__vswprintf_chk (wchar_t *s, size_t maxlen, int flags, size_t slen,
29 const wchar_t *format, va_list args)
30{
31 /* XXX Maybe for less strict version do not fail immediately.
32 Though, maxlen is supposed to be the size of buffer pointed
33 to by s, so a conforming program can't pass such maxlen
34 to *snprintf. */
35 if (__glibc_unlikely (slen < maxlen))
36 __chk_fail ();
37
38 _IO_wstrnfile sf;
39 struct _IO_wide_data wd;
40 int ret;
41#ifdef _IO_MTSAFE_IO
42 sf.f._sbf._f._lock = NULL;
43#endif
44
45 /* We need to handle the special case where MAXLEN is 0. Use the
46 overflow buffer right from the start. */
47 if (__glibc_unlikely (maxlen == 0))
48 /* Since we have to write at least the terminating L'\0' a buffer
49 length of zero always makes the function fail. */
50 return -1;
51
52 _IO_no_init (&sf.f._sbf._f, _IO_USER_LOCK, 0, &wd, &_IO_wstrn_jumps);
53 _IO_fwide (&sf.f._sbf._f, 1);
54 s[0] = L'\0';
55
56 /* For flags > 0 (i.e. __USE_FORTIFY_LEVEL > 1) request that %n
57 can only come from read-only format strings. */
58 if (flags > 0)
59 sf.f._sbf._f._flags2 |= _IO_FLAGS2_FORTIFY;
60
61 _IO_wstr_init_static (&sf.f._sbf._f, s, maxlen - 1, s);
62 ret = _IO_vfwprintf ((_IO_FILE *) &sf.f._sbf, format, args);
63
64 if (sf.f._sbf._f._wide_data->_IO_buf_base == sf.overflow_buf)
65 /* ISO C99 requires swprintf/vswprintf to return an error if the
66 output does not fit int he provided buffer. */
67 return -1;
68
69 /* Terminate the string. */
70 *sf.f._sbf._f._wide_data->_IO_write_ptr = '\0';
71
72 return ret;
73}
74libc_hidden_def (__vswprintf_chk)
75