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lib/libc/secure/__strncpy_chk.c
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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. | |||||
| * | |||||
| * bionic rev: d807b9a12d3e49132b095df3d883618452033b51 | |||||
| * | |||||
| * $FreeBSD$ | |||||
| */ | |||||
| #undef _FORTIFY_SOURCE | |||||
| #include <sys/cdefs.h> | |||||
| #include <secure/security.h> | |||||
| #include <string.h> | |||||
| #include <stdlib.h> | |||||
| #include "secure/_string.h" | |||||
| char * | |||||
| __strncpy_chk(char *__restrict d, const char *__restrict s, size_t n, size_t bos) | |||||
| { | |||||
| if (__predict_false(bos == __FORTIFY_UNKNOWN_SIZE)) | |||||
| return (strncpy(d, s, n)); | |||||
| if (__predict_false(n > bos)) | |||||
| __fortify_chk_fail( | |||||
| "strncpy: prevented write past end of buffer"); | |||||
| return (strncpy(d, s, n)); | |||||
| } | |||||
| /* | |||||
| * __strncpy_chk2 | |||||
| * | |||||
| * This is a variant of __strncpy_chk, but it also checks to make | |||||
| * sure we don't read beyond the end of "src". The code for this is | |||||
| * based on the original version of strncpy, but modified to check | |||||
| * how much we read from "src" at the end of the copy operation. | |||||
| */ | |||||
| char * | |||||
| __strncpy_chk2(char *__restrict d, const char *__restrict s, size_t n, size_t d_bos, size_t s_bos) | |||||
| { | |||||
| size_t s_copy_len; | |||||
| if (__predict_false(d_bos == __FORTIFY_UNKNOWN_SIZE)) | |||||
| return (strncpy(d, s, n)); | |||||
| if (__predict_false(s_bos == __FORTIFY_UNKNOWN_SIZE)) | |||||
| return (__strncpy_chk(d, s, n, d_bos)); | |||||
| if (__predict_false(n > d_bos)) | |||||
| __fortify_chk_fail("strncpy: prevented write past end of buffer"); | |||||
| if (n != 0) { | |||||
| char *_d = d; | |||||
| const char *_s = s; | |||||
| do { | |||||
| if ((*_d++ = *_s++) == 0) { | |||||
| /* NUL pad the remaining n-1 bytes */ | |||||
| while (--n != 0) | |||||
| *_d++ = 0; | |||||
| break; | |||||
| } | |||||
| } while (--n != 0); | |||||
| s_copy_len = (size_t)(_s - s); | |||||
| if (__predict_false(s_copy_len > s_bos)) | |||||
| __fortify_chk_fail("strncpy: prevented read past end of buffer"); | |||||
| } | |||||
| return (d); | |||||
| } | |||||