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/*
* Copyright (C) 2012 The Android Open Source Project
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <string.h>
#include <stdlib.h>
#include "private/libc_logging.h"
/*
* Runtime implementation of __builtin____strncat_chk.
*
* See
* http://gcc.gnu.org/onlinedocs/gcc/Object-Size-Checking.html
* http://gcc.gnu.org/ml/gcc-patches/2004-09/msg02055.html
* for details.
*
* This strncat check is called if _FORTIFY_SOURCE is defined and
* greater than 0.
*/
extern "C" char* __strncat_chk(char* __restrict dest, const char* __restrict src,
size_t len, size_t dest_buf_size) {
if (len == 0) {
return dest;
}
size_t dest_len = __strlen_chk(dest, dest_buf_size);
char *d = dest + dest_len;
dest_buf_size -= dest_len;
while (*src != '\0') {
*d++ = *src++;
len--; dest_buf_size--;
if (__predict_false(dest_buf_size == 0)) {
__fortify_chk_fail("strncat: prevented write past end of buffer",
BIONIC_EVENT_STRNCAT_BUFFER_OVERFLOW);
}
if (len == 0) {
break;
}
}
*d = '\0';
return dest;
}
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