elf_rand.c revision 272461
1/*- 2 * Copyright (c) 2006 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 <sys/cdefs.h> 28__FBSDID("$FreeBSD: releng/10.1/lib/libelf/elf_rand.c 164190 2006-11-11 17:16:35Z jkoshy $"); 29 30#include <ar.h> 31#include <libelf.h> 32 33#include "_libelf.h" 34 35off_t 36elf_rand(Elf *ar, off_t offset) 37{ 38 struct ar_hdr *arh; 39 40 if (ar == NULL || ar->e_kind != ELF_K_AR || 41 (offset & 1) || offset < SARMAG || 42 offset + sizeof(struct ar_hdr) >= ar->e_rawsize) { 43 LIBELF_SET_ERROR(ARGUMENT, 0); 44 return 0; 45 } 46 47 arh = (struct ar_hdr *) (ar->e_rawfile + offset); 48 49 /* a too simple sanity check */ 50 if (arh->ar_fmag[0] != '`' || arh->ar_fmag[1] != '\n') { 51 LIBELF_SET_ERROR(ARCHIVE, 0); 52 return 0; 53 } 54 55 ar->e_u.e_ar.e_next = offset; 56 57 return (offset); 58} 59