10a2301598c207fd1b50015984942fee5e8511593Nick Kralevich/* 20a2301598c207fd1b50015984942fee5e8511593Nick Kralevich * Copyright (C) 2012 The Android Open Source Project 30a2301598c207fd1b50015984942fee5e8511593Nick Kralevich * All rights reserved. 40a2301598c207fd1b50015984942fee5e8511593Nick Kralevich * 50a2301598c207fd1b50015984942fee5e8511593Nick Kralevich * Redistribution and use in source and binary forms, with or without 60a2301598c207fd1b50015984942fee5e8511593Nick Kralevich * modification, are permitted provided that the following conditions 70a2301598c207fd1b50015984942fee5e8511593Nick Kralevich * are met: 80a2301598c207fd1b50015984942fee5e8511593Nick Kralevich * * Redistributions of source code must retain the above copyright 90a2301598c207fd1b50015984942fee5e8511593Nick Kralevich * notice, this list of conditions and the following disclaimer. 100a2301598c207fd1b50015984942fee5e8511593Nick Kralevich * * Redistributions in binary form must reproduce the above copyright 110a2301598c207fd1b50015984942fee5e8511593Nick Kralevich * notice, this list of conditions and the following disclaimer in 120a2301598c207fd1b50015984942fee5e8511593Nick Kralevich * the documentation and/or other materials provided with the 130a2301598c207fd1b50015984942fee5e8511593Nick Kralevich * distribution. 140a2301598c207fd1b50015984942fee5e8511593Nick Kralevich * 150a2301598c207fd1b50015984942fee5e8511593Nick Kralevich * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 160a2301598c207fd1b50015984942fee5e8511593Nick Kralevich * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 170a2301598c207fd1b50015984942fee5e8511593Nick Kralevich * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 180a2301598c207fd1b50015984942fee5e8511593Nick Kralevich * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 190a2301598c207fd1b50015984942fee5e8511593Nick Kralevich * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 200a2301598c207fd1b50015984942fee5e8511593Nick Kralevich * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 210a2301598c207fd1b50015984942fee5e8511593Nick Kralevich * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 220a2301598c207fd1b50015984942fee5e8511593Nick Kralevich * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 230a2301598c207fd1b50015984942fee5e8511593Nick Kralevich * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 240a2301598c207fd1b50015984942fee5e8511593Nick Kralevich * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 250a2301598c207fd1b50015984942fee5e8511593Nick Kralevich * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 260a2301598c207fd1b50015984942fee5e8511593Nick Kralevich * SUCH DAMAGE. 270a2301598c207fd1b50015984942fee5e8511593Nick Kralevich */ 280a2301598c207fd1b50015984942fee5e8511593Nick Kralevich 290a2301598c207fd1b50015984942fee5e8511593Nick Kralevich#include <string.h> 300a2301598c207fd1b50015984942fee5e8511593Nick Kralevich#include <stdlib.h> 31eb847bc8666842a3cfc9c06e8458ad1abebebaf0Elliott Hughes#include "private/libc_logging.h" 320a2301598c207fd1b50015984942fee5e8511593Nick Kralevich 330a2301598c207fd1b50015984942fee5e8511593Nick Kralevich/* 340a2301598c207fd1b50015984942fee5e8511593Nick Kralevich * Runtime implementation of __builtin____strcat_chk. 350a2301598c207fd1b50015984942fee5e8511593Nick Kralevich * 360a2301598c207fd1b50015984942fee5e8511593Nick Kralevich * See 370a2301598c207fd1b50015984942fee5e8511593Nick Kralevich * http://gcc.gnu.org/onlinedocs/gcc/Object-Size-Checking.html 380a2301598c207fd1b50015984942fee5e8511593Nick Kralevich * http://gcc.gnu.org/ml/gcc-patches/2004-09/msg02055.html 390a2301598c207fd1b50015984942fee5e8511593Nick Kralevich * for details. 400a2301598c207fd1b50015984942fee5e8511593Nick Kralevich * 410a2301598c207fd1b50015984942fee5e8511593Nick Kralevich * This strcat check is called if _FORTIFY_SOURCE is defined and 420a2301598c207fd1b50015984942fee5e8511593Nick Kralevich * greater than 0. 430a2301598c207fd1b50015984942fee5e8511593Nick Kralevich */ 44d1eda33f012e46083b91e087fb79d14a5ce70f0eElliott Hughesextern "C" char* __strcat_chk(char* __restrict dest, const char* __restrict src, 45d1eda33f012e46083b91e087fb79d14a5ce70f0eElliott Hughes size_t dest_buf_size) { 46d1eda33f012e46083b91e087fb79d14a5ce70f0eElliott Hughes char* save = dest; 47d1eda33f012e46083b91e087fb79d14a5ce70f0eElliott Hughes size_t dest_len = __strlen_chk(dest, dest_buf_size); 480a2301598c207fd1b50015984942fee5e8511593Nick Kralevich 49d1eda33f012e46083b91e087fb79d14a5ce70f0eElliott Hughes dest += dest_len; 50d1eda33f012e46083b91e087fb79d14a5ce70f0eElliott Hughes dest_buf_size -= dest_len; 5176656afc6dd069fcfda5768e6e54bb85e4e99942Nick Kralevich 52d1eda33f012e46083b91e087fb79d14a5ce70f0eElliott Hughes while ((*dest++ = *src++) != '\0') { 53d1eda33f012e46083b91e087fb79d14a5ce70f0eElliott Hughes dest_buf_size--; 54d1eda33f012e46083b91e087fb79d14a5ce70f0eElliott Hughes if (__predict_false(dest_buf_size == 0)) { 55d1eda33f012e46083b91e087fb79d14a5ce70f0eElliott Hughes __fortify_chk_fail("strcat: prevented write past end of buffer", 56d1eda33f012e46083b91e087fb79d14a5ce70f0eElliott Hughes BIONIC_EVENT_STRCAT_BUFFER_OVERFLOW); 570a2301598c207fd1b50015984942fee5e8511593Nick Kralevich } 58d1eda33f012e46083b91e087fb79d14a5ce70f0eElliott Hughes } 590a2301598c207fd1b50015984942fee5e8511593Nick Kralevich 60d1eda33f012e46083b91e087fb79d14a5ce70f0eElliott Hughes return save; 610a2301598c207fd1b50015984942fee5e8511593Nick Kralevich} 62