1 /* Convert from file to memory representation.
2 Copyright (C) 1998, 1999, 2000, 2002, 2012, 2015 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
45 Elf_Data *
elfw2(LIBELFBITS,xlatetom)46 elfw2(LIBELFBITS, xlatetom) (Elf_Data *dest, const Elf_Data *src,
47 unsigned int encode)
48 {
49 /* First test whether the input data is really suitable for this
50 type. This means, whether there is an integer number of records.
51 Note that for this implementation the memory and file size of the
52 data types are identical. */
53 #if EV_NUM != 2
54 size_t recsize = __libelf_type_sizes[src->d_version - 1][ELFW(ELFCLASS,LIBELFBITS) - 1][src->d_type];
55 #else
56 size_t recsize = __libelf_type_sizes[0][ELFW(ELFCLASS,LIBELFBITS) - 1][src->d_type];
57 #endif
58
59
60 /* We shouldn't require integer number of records when processing
61 notes. Payload bytes follow the header immediately, it's not an
62 array of records as is the case otherwise. */
63 if (src->d_type != ELF_T_NHDR
64 && src->d_size % recsize != 0)
65 {
66 __libelf_seterrno (ELF_E_INVALID_DATA);
67 return NULL;
68 }
69
70 /* Next see whether the converted data fits in the output buffer. */
71 if (src->d_size > dest->d_size)
72 {
73 __libelf_seterrno (ELF_E_DEST_SIZE);
74 return NULL;
75 }
76
77 /* Test the encode parameter. */
78 if (encode != ELFDATA2LSB && encode != ELFDATA2MSB)
79 {
80 __libelf_seterrno (ELF_E_INVALID_ENCODING);
81 return NULL;
82 }
83
84 /* Determine the translation function to use.
85
86 At this point we make an assumption which is valid for all
87 existing implementations so far: the memory and file sizes are
88 the same. This has very important consequences:
89 a) The requirement that the source and destination buffer can
90 overlap can easily be fulfilled.
91 b) We need only one function to convert from and memory to file
92 and vice versa since the function only has to copy and/or
93 change the byte order.
94 */
95 if ((BYTE_ORDER == LITTLE_ENDIAN && encode == ELFDATA2LSB)
96 || (BYTE_ORDER == BIG_ENDIAN && encode == ELFDATA2MSB))
97 {
98 /* We simply have to copy since the byte order is the same. */
99 if (src->d_buf != dest->d_buf)
100 memmove (dest->d_buf, src->d_buf, src->d_size);
101 }
102 else
103 {
104 xfct_t fctp;
105
106 /* Get a pointer to the transformation functions. The `#ifdef' is
107 a small optimization since we don't anticipate another ELF
108 version and so would waste "precious" code. */
109 #if EV_NUM != 2
110 fctp = __elf_xfctstom[src->d_version - 1][dest->d_version - 1][ELFW(ELFCLASS, LIBELFBITS) - 1][src->d_type];
111 #else
112 fctp = __elf_xfctstom[0][0][ELFW(ELFCLASS, LIBELFBITS) - 1][src->d_type];
113 #endif
114
115 /* Do the real work. */
116 (*fctp) (dest->d_buf, src->d_buf, src->d_size, 0);
117 }
118
119 /* Now set the real destination type and length since the operation was
120 successful. */
121 dest->d_type = src->d_type;
122 dest->d_size = src->d_size;
123
124 return dest;
125 }
126 INTDEF(elfw2(LIBELFBITS, xlatetom))
127