1/* Convert from file to memory representation.
2   Copyright (C) 1998, 1999, 2000, 2002, 2012 Red Hat, Inc.
3   This file is part of elfutils.
4   Written by Ulrich Drepper <drepper@redhat.com>, 1998.
5
6   This file is free software; you can redistribute it and/or modify
7   it under the terms of either
8
9     * the GNU Lesser General Public License as published by the Free
10       Software Foundation; either version 3 of the License, or (at
11       your option) any later version
12
13   or
14
15     * the GNU General Public License as published by the Free
16       Software Foundation; either version 2 of the License, or (at
17       your option) any later version
18
19   or both in parallel, as here.
20
21   elfutils is distributed in the hope that it will be useful, but
22   WITHOUT ANY WARRANTY; without even the implied warranty of
23   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
24   General Public License for more details.
25
26   You should have received copies of the GNU General Public License and
27   the GNU Lesser General Public License along with this program.  If
28   not, see <http://www.gnu.org/licenses/>.  */
29
30#ifdef HAVE_CONFIG_H
31# include <config.h>
32#endif
33
34#include <assert.h>
35#include <endian.h>
36#include <string.h>
37
38#include "libelfP.h"
39
40#ifndef LIBELFBITS
41# define LIBELFBITS	32
42#endif
43
44
45Elf_Data *
46elfw2(LIBELFBITS, xlatetom) (dest, src, encode)
47     Elf_Data *dest;
48     const Elf_Data *src;
49     unsigned int encode;
50{
51  /* First test whether the input data is really suitable for this
52     type.  This means, whether there is an integer number of records.
53     Note that for this implementation the memory and file size of the
54     data types are identical.  */
55#if EV_NUM != 2
56  size_t recsize = __libelf_type_sizes[src->d_version - 1][ELFW(ELFCLASS,LIBELFBITS) - 1][src->d_type];
57#else
58  size_t recsize = __libelf_type_sizes[0][ELFW(ELFCLASS,LIBELFBITS) - 1][src->d_type];
59#endif
60
61
62  /* We shouldn't require integer number of records when processing
63     notes.  Payload bytes follow the header immediately, it's not an
64     array of records as is the case otherwise.  */
65  if (src->d_type != ELF_T_NHDR
66      && src->d_size % recsize != 0)
67    {
68      __libelf_seterrno (ELF_E_INVALID_DATA);
69      return NULL;
70    }
71
72  /* Next see whether the converted data fits in the output buffer.  */
73  if (src->d_size > dest->d_size)
74    {
75      __libelf_seterrno (ELF_E_DEST_SIZE);
76      return NULL;
77    }
78
79  /* Test the encode parameter.  */
80  if (encode != ELFDATA2LSB && encode != ELFDATA2MSB)
81    {
82      __libelf_seterrno (ELF_E_INVALID_ENCODING);
83      return NULL;
84    }
85
86  /* Determine the translation function to use.
87
88     At this point we make an assumption which is valid for all
89     existing implementations so far: the memory and file sizes are
90     the same.  This has very important consequences:
91     a) The requirement that the source and destination buffer can
92	overlap can easily be fulfilled.
93     b) We need only one function to convert from and memory to file
94	and vice versa since the function only has to copy and/or
95	change the byte order.
96  */
97  if ((BYTE_ORDER == LITTLE_ENDIAN && encode == ELFDATA2LSB)
98      || (BYTE_ORDER == BIG_ENDIAN && encode == ELFDATA2MSB))
99    {
100      /* We simply have to copy since the byte order is the same.  */
101      if (src->d_buf != dest->d_buf)
102	memmove (dest->d_buf, src->d_buf, src->d_size);
103    }
104  else
105    {
106      xfct_t fctp;
107
108      /* Get a pointer to the transformation functions.  The `#ifdef' is
109	 a small optimization since we don't anticipate another ELF
110	 version and so would waste "precious" code.  */
111#if EV_NUM != 2
112      fctp = __elf_xfctstom[src->d_version - 1][dest->d_version - 1][ELFW(ELFCLASS, LIBELFBITS) - 1][src->d_type];
113#else
114      fctp = __elf_xfctstom[0][0][ELFW(ELFCLASS, LIBELFBITS) - 1][src->d_type];
115#endif
116
117      /* Do the real work.  */
118      (*fctp) (dest->d_buf, src->d_buf, src->d_size, 0);
119    }
120
121  /* Now set the real destination type and length since the operation was
122     successful.  */
123  dest->d_type = src->d_type;
124  dest->d_size = src->d_size;
125
126  return dest;
127}
128INTDEF(elfw2(LIBELFBITS, xlatetom))
129