1/* Copyright (C) 1993-2022 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 <https://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 "strfile.h"
29
30static int __THROW
31_IO_str_chk_overflow (FILE *fp, int c)
32{
33 /* If we get here, the user-supplied buffer would be overrun by
34 further output. */
35 __chk_fail ();
36}
37
38static const struct _IO_jump_t _IO_str_chk_jumps libio_vtable =
39{
40 JUMP_INIT_DUMMY,
41 JUMP_INIT(finish, _IO_str_finish),
42 JUMP_INIT(overflow, _IO_str_chk_overflow),
43 JUMP_INIT(underflow, _IO_str_underflow),
44 JUMP_INIT(uflow, _IO_default_uflow),
45 JUMP_INIT(pbackfail, _IO_str_pbackfail),
46 JUMP_INIT(xsputn, _IO_default_xsputn),
47 JUMP_INIT(xsgetn, _IO_default_xsgetn),
48 JUMP_INIT(seekoff, _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, _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/* This function is called by regular vsprintf with maxlen set to -1,
63 and by vsprintf_chk with maxlen set to the size of the output
64 string. In the former case, _IO_str_chk_overflow will never be
65 called; in the latter case it will crash the program if the buffer
66 overflows. */
67
68int
69__vsprintf_internal (char *string, size_t maxlen,
70 const char *format, va_list args,
71 unsigned int mode_flags)
72{
73 _IO_strfile sf;
74 int ret;
75
76#ifdef _IO_MTSAFE_IO
77 sf._sbf._f._lock = NULL;
78#endif
79 _IO_no_init (&sf._sbf._f, _IO_USER_LOCK, -1, NULL, NULL);
80 /* When called from fortified sprintf/vsprintf, erase the destination
81 buffer and try to detect overflows. When called from regular
82 sprintf/vsprintf, do not erase the destination buffer, because
83 known user code relies on this behavior (even though its undefined
84 by ISO C), nor try to detect overflows. */
85 if ((mode_flags & PRINTF_CHK) != 0)
86 {
87 _IO_JUMPS (&sf._sbf) = &_IO_str_chk_jumps;
88 string[0] = '\0';
89 }
90 else
91 _IO_JUMPS (&sf._sbf) = &_IO_str_jumps;
92 _IO_str_init_static_internal (&sf, string,
93 (maxlen == -1) ? -1 : maxlen - 1,
94 string);
95
96 ret = __vfprintf_internal (&sf._sbf._f, format, args, mode_flags);
97
98 *sf._sbf._f._IO_write_ptr = '\0';
99 return ret;
100}
101
102int
103__vsprintf (char *string, const char *format, va_list args)
104{
105 return __vsprintf_internal (string, -1, format, args, 0);
106}
107
108ldbl_strong_alias (__vsprintf, _IO_vsprintf)
109ldbl_weak_alias (__vsprintf, vsprintf)
110