Home | History | Annotate | Download | only in bionic
      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 #undef _FORTIFY_SOURCE
     30 
     31 #include <string.h>
     32 #include <stdlib.h>
     33 #include "private/libc_logging.h"
     34 
     35 /*
     36  * __strlcat_chk. Called in place of strlcat() when we know the
     37  * size of the buffer we're writing into.
     38  *
     39  * See
     40  *   http://gcc.gnu.org/onlinedocs/gcc/Object-Size-Checking.html
     41  *   http://gcc.gnu.org/ml/gcc-patches/2004-09/msg02055.html
     42  * for details.
     43  *
     44  * This strlcat check is called if _FORTIFY_SOURCE is defined and
     45  * greater than 0.
     46  */
     47 extern "C" size_t __strlcat_chk(char* dest, const char* src,
     48                                 size_t supplied_size, size_t dest_len_from_compiler) {
     49   if (__predict_false(supplied_size > dest_len_from_compiler)) {
     50     __fortify_chk_fail("strlcat: prevented write past end of buffer", 0);
     51   }
     52 
     53   return strlcat(dest, src, supplied_size);
     54 }
     55