| xf.li | bdd93d5 | 2023-05-12 07:10:14 -0700 | [diff] [blame^] | 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 <stdio.h> |
| 20 | #include "../libio/libioP.h" |
| 21 | #include "../libio/strfile.h" |
| 22 | |
| 23 | extern const struct _IO_jump_t _IO_strn_jumps attribute_hidden; |
| 24 | |
| 25 | /* Write formatted output into S, according to the format |
| 26 | string FORMAT, writing no more than MAXLEN characters. */ |
| 27 | /* VARARGS5 */ |
| 28 | int |
| 29 | ___vsnprintf_chk (char *s, size_t maxlen, int flags, size_t slen, |
| 30 | const char *format, va_list args) |
| 31 | { |
| 32 | /* XXX Maybe for less strict version do not fail immediately. |
| 33 | Though, maxlen is supposed to be the size of buffer pointed |
| 34 | to by s, so a conforming program can't pass such maxlen |
| 35 | to *snprintf. */ |
| 36 | if (__glibc_unlikely (slen < maxlen)) |
| 37 | __chk_fail (); |
| 38 | |
| 39 | _IO_strnfile sf; |
| 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 (maxlen == 0) |
| 48 | { |
| 49 | s = sf.overflow_buf; |
| 50 | maxlen = sizeof (sf.overflow_buf); |
| 51 | } |
| 52 | |
| 53 | _IO_no_init (&sf.f._sbf._f, _IO_USER_LOCK, -1, NULL, NULL); |
| 54 | _IO_JUMPS (&sf.f._sbf) = &_IO_strn_jumps; |
| 55 | s[0] = '\0'; |
| 56 | |
| 57 | /* For flags > 0 (i.e. __USE_FORTIFY_LEVEL > 1) request that %n |
| 58 | can only come from read-only format strings. */ |
| 59 | if (flags > 0) |
| 60 | sf.f._sbf._f._flags2 |= _IO_FLAGS2_FORTIFY; |
| 61 | |
| 62 | _IO_str_init_static_internal (&sf.f, s, maxlen - 1, s); |
| 63 | ret = _IO_vfprintf (&sf.f._sbf._f, format, args); |
| 64 | |
| 65 | if (sf.f._sbf._f._IO_buf_base != sf.overflow_buf) |
| 66 | *sf.f._sbf._f._IO_write_ptr = '\0'; |
| 67 | return ret; |
| 68 | } |
| 69 | ldbl_hidden_def (___vsnprintf_chk, __vsnprintf_chk) |
| 70 | ldbl_strong_alias (___vsnprintf_chk, __vsnprintf_chk) |