1 /* $NetBSD: elf_rand.c,v 1.3 2016/02/20 02:43:42 christos Exp $ */ 2 3 /*- 4 * Copyright (c) 2006,2008 Joseph Koshy 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <ar.h> 30 #include <libelf.h> 31 32 #include "_libelf.h" 33 34 __RCSID("$NetBSD: elf_rand.c,v 1.3 2016/02/20 02:43:42 christos Exp $"); 35 ELFTC_VCSID("Id: elf_rand.c 3174 2015-03-27 17:13:41Z emaste "); 36 37 off_t 38 elf_rand(Elf *ar, off_t offset) 39 { 40 struct ar_hdr *arh; 41 42 if (ar == NULL || ar->e_kind != ELF_K_AR || 43 (offset & 1) || offset < SARMAG || 44 (size_t) offset + sizeof(struct ar_hdr) >= ar->e_rawsize) { 45 LIBELF_SET_ERROR(ARGUMENT, 0); 46 return 0; 47 } 48 49 arh = (struct ar_hdr *) (ar->e_rawfile + offset); 50 51 /* a too simple sanity check */ 52 if (arh->ar_fmag[0] != '`' || arh->ar_fmag[1] != '\n') { 53 LIBELF_SET_ERROR(ARCHIVE, 0); 54 return 0; 55 } 56 57 ar->e_u.e_ar.e_next = offset; 58 59 return (offset); 60 } 61