__strlcpy_chk.cpp revision 326ea5413d18ea019cd1bda415ce428f7bdcafd2 
1/*
2 * Copyright (C) 2012 The Android Open Source Project
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *  * Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 *  * Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in
12 *    the documentation and/or other materials provided with the
13 *    distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29#include <string.h>
30#include <stdlib.h>
31#include <private/logd.h>
32
33/*
34 * __strlcpy_chk. Called in place of strlcpy() when we know the
35 * size of the buffer we're writing into.
36 *
37 * See
38 *   http://gcc.gnu.org/onlinedocs/gcc/Object-Size-Checking.html
39 *   http://gcc.gnu.org/ml/gcc-patches/2004-09/msg02055.html
40 * for details.
41 *
42 * This strlcpy check is called if _FORTIFY_SOURCE is defined and
43 * greater than 0.
44 */
45extern "C" size_t __strlcpy_chk(char *dest, const char *src,
46              size_t supplied_size, size_t dest_len_from_compiler)
47{
48    if (supplied_size > dest_len_from_compiler) {
49        __fortify_chk_fail("strlcpy buffer overflow", 0);
50    }
51
52    return strlcpy(dest, src, supplied_size);
53}
54