1 /*- 2 * Copyright (c) 2006,2008 Joseph Koshy 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 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27 #include <ar.h> 28 #include <libelf.h> 29 30 #include "_libelf.h" 31 32 ELFTC_VCSID("$Id: elf_rand.c 3174 2015-03-27 17:13:41Z emaste $"); 33 34 off_t 35 elf_rand(Elf *ar, off_t offset) 36 { 37 struct ar_hdr *arh; 38 39 if (ar == NULL || ar->e_kind != ELF_K_AR || 40 (offset & 1) || offset < SARMAG || 41 (size_t) offset + sizeof(struct ar_hdr) >= ar->e_rawsize) { 42 LIBELF_SET_ERROR(ARGUMENT, 0); 43 return 0; 44 } 45 46 arh = (struct ar_hdr *) (ar->e_rawfile + offset); 47 48 /* a too simple sanity check */ 49 if (arh->ar_fmag[0] != '`' || arh->ar_fmag[1] != '\n') { 50 LIBELF_SET_ERROR(ARCHIVE, 0); 51 return 0; 52 } 53 54 ar->e_u.e_ar.e_next = offset; 55 56 return (offset); 57 } 58