1164190Sjkoshy/*- 2164190Sjkoshy * Copyright (c) 2006 Joseph Koshy 3164190Sjkoshy * All rights reserved. 4164190Sjkoshy * 5164190Sjkoshy * Redistribution and use in source and binary forms, with or without 6164190Sjkoshy * modification, are permitted provided that the following conditions 7164190Sjkoshy * are met: 8164190Sjkoshy * 1. Redistributions of source code must retain the above copyright 9164190Sjkoshy * notice, this list of conditions and the following disclaimer. 10164190Sjkoshy * 2. Redistributions in binary form must reproduce the above copyright 11164190Sjkoshy * notice, this list of conditions and the following disclaimer in the 12164190Sjkoshy * documentation and/or other materials provided with the distribution. 13164190Sjkoshy * 14164190Sjkoshy * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15164190Sjkoshy * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16164190Sjkoshy * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17164190Sjkoshy * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18164190Sjkoshy * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19164190Sjkoshy * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20164190Sjkoshy * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21164190Sjkoshy * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22164190Sjkoshy * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23164190Sjkoshy * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24164190Sjkoshy * SUCH DAMAGE. 25164190Sjkoshy */ 26164190Sjkoshy 27164190Sjkoshy#include <sys/cdefs.h> 28164190Sjkoshy__FBSDID("$FreeBSD$"); 29164190Sjkoshy 30164190Sjkoshy#include <assert.h> 31164190Sjkoshy#include <libelf.h> 32164190Sjkoshy 33164190Sjkoshy#include "_libelf.h" 34164190Sjkoshy 35164190Sjkoshy/* 36164190Sjkoshy * Translate to/from the file representation of ELF objects. 37164190Sjkoshy * 38164190Sjkoshy * Translation could potentially involve the following 39164190Sjkoshy * transformations: 40164190Sjkoshy * 41164190Sjkoshy * - an endianness conversion, 42164190Sjkoshy * - a change of layout, as the file representation of ELF objects 43164190Sjkoshy * can differ from their in-memory representation. 44164190Sjkoshy * - a change in representation due to a layout version change. 45164190Sjkoshy */ 46164190Sjkoshy 47164190SjkoshyElf_Data * 48164190Sjkoshy_libelf_xlate(Elf_Data *dst, const Elf_Data *src, unsigned int encoding, 49164190Sjkoshy int elfclass, int direction) 50164190Sjkoshy{ 51210338Skaiw int byteswap; 52164190Sjkoshy size_t cnt, dsz, fsz, msz; 53164190Sjkoshy uintptr_t sb, se, db, de; 54164190Sjkoshy 55164190Sjkoshy if (encoding == ELFDATANONE) 56164190Sjkoshy encoding = LIBELF_PRIVATE(byteorder); 57164190Sjkoshy 58164190Sjkoshy if ((encoding != ELFDATA2LSB && encoding != ELFDATA2MSB) || 59164190Sjkoshy dst == NULL || src == NULL || dst == src) { 60164190Sjkoshy LIBELF_SET_ERROR(ARGUMENT, 0); 61164190Sjkoshy return (NULL); 62164190Sjkoshy } 63164190Sjkoshy 64164190Sjkoshy assert(elfclass == ELFCLASS32 || elfclass == ELFCLASS64); 65164190Sjkoshy assert(direction == ELF_TOFILE || direction == ELF_TOMEMORY); 66164190Sjkoshy 67164190Sjkoshy if (dst->d_version != src->d_version) { 68164190Sjkoshy LIBELF_SET_ERROR(UNIMPL, 0); 69164190Sjkoshy return (NULL); 70164190Sjkoshy } 71164190Sjkoshy 72173924Sjkoshy if (src->d_buf == NULL || dst->d_buf == NULL) { 73164190Sjkoshy LIBELF_SET_ERROR(DATA, 0); 74164190Sjkoshy return (NULL); 75164190Sjkoshy } 76164190Sjkoshy 77164190Sjkoshy if ((int) src->d_type < 0 || src->d_type >= ELF_T_NUM) { 78164190Sjkoshy LIBELF_SET_ERROR(DATA, 0); 79164190Sjkoshy return (NULL); 80164190Sjkoshy } 81164190Sjkoshy 82173924Sjkoshy if ((fsz = (elfclass == ELFCLASS32 ? elf32_fsize : elf64_fsize) 83173924Sjkoshy (src->d_type, (size_t) 1, src->d_version)) == 0) 84164190Sjkoshy return (NULL); 85164190Sjkoshy 86164190Sjkoshy msz = _libelf_msize(src->d_type, elfclass, src->d_version); 87164190Sjkoshy 88164190Sjkoshy assert(msz > 0); 89164190Sjkoshy 90164190Sjkoshy if (src->d_size % (direction == ELF_TOMEMORY ? fsz : msz)) { 91164190Sjkoshy LIBELF_SET_ERROR(DATA, 0); 92164190Sjkoshy return (NULL); 93164190Sjkoshy } 94164190Sjkoshy 95165523Sjkoshy /* 96165523Sjkoshy * Determine the number of objects that need to be converted, and 97165523Sjkoshy * the space required for the converted objects in the destination 98165523Sjkoshy * buffer. 99165523Sjkoshy */ 100165523Sjkoshy if (direction == ELF_TOMEMORY) { 101165523Sjkoshy cnt = src->d_size / fsz; 102165523Sjkoshy dsz = cnt * msz; 103165523Sjkoshy } else { 104165523Sjkoshy cnt = src->d_size / msz; 105165523Sjkoshy dsz = cnt * fsz; 106165523Sjkoshy } 107164190Sjkoshy 108164190Sjkoshy if (dst->d_size < dsz) { 109164190Sjkoshy LIBELF_SET_ERROR(DATA, 0); 110164190Sjkoshy return (NULL); 111164190Sjkoshy } 112164190Sjkoshy 113164190Sjkoshy sb = (uintptr_t) src->d_buf; 114164190Sjkoshy se = sb + src->d_size; 115164190Sjkoshy db = (uintptr_t) dst->d_buf; 116164190Sjkoshy de = db + dst->d_size; 117164190Sjkoshy 118164190Sjkoshy /* 119164190Sjkoshy * Check for overlapping buffers. Note that db == sb is 120165523Sjkoshy * allowed. 121164190Sjkoshy */ 122165523Sjkoshy if (db != sb && de > sb && se > db) { 123164190Sjkoshy LIBELF_SET_ERROR(DATA, 0); 124164190Sjkoshy return (NULL); 125164190Sjkoshy } 126164190Sjkoshy 127164190Sjkoshy if ((direction == ELF_TOMEMORY ? db : sb) % 128164190Sjkoshy _libelf_malign(src->d_type, elfclass)) { 129164190Sjkoshy LIBELF_SET_ERROR(DATA, 0); 130164190Sjkoshy return (NULL); 131164190Sjkoshy } 132164190Sjkoshy 133164190Sjkoshy dst->d_type = src->d_type; 134165523Sjkoshy dst->d_size = dsz; 135164190Sjkoshy 136210338Skaiw byteswap = encoding != LIBELF_PRIVATE(byteorder); 137210338Skaiw 138173924Sjkoshy if (src->d_size == 0 || 139210338Skaiw (db == sb && !byteswap && fsz == msz)) 140164190Sjkoshy return (dst); /* nothing more to do */ 141164190Sjkoshy 142210338Skaiw if (!(_libelf_get_translator(src->d_type, direction, elfclass)) 143210338Skaiw (dst->d_buf, dsz, src->d_buf, cnt, byteswap)) { 144210338Skaiw LIBELF_SET_ERROR(DATA, 0); 145210338Skaiw return (NULL); 146210338Skaiw } 147164190Sjkoshy 148164190Sjkoshy return (dst); 149164190Sjkoshy} 150