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
28#include <assert.h>
29#include <errno.h>
30#include "libelf.h"
31#include <stdlib.h>
32
33#include "_libelf.h"
34
35
36Elf_Data *
37elf_getdata(Elf_Scn *s, Elf_Data *d)
38{
39        Elf *e;
40        char *dst;
41        size_t fsz, msz, count;
42        int elfclass, elftype;
43        unsigned int sh_type;
44        uint64_t sh_align, sh_offset, sh_size;
45        void (*xlate)(char *_d, char *_s, size_t _c, int _swap);
46
47        if (s == NULL || (e = s->s_elf) == NULL || e->e_kind != ELF_K_ELF ||
48            (d != NULL && s != d->d_scn)) {
49                LIBELF_SET_ERROR(ARGUMENT, 0);
50                return (NULL);
51        }
52
53        if (d == NULL && (d = STAILQ_FIRST(&s->s_data)) != NULL)
54                return (d);
55
56        if (d != NULL)
57                return (STAILQ_NEXT(d, d_next));
58
59        if (e->e_rawfile == NULL) {
60                LIBELF_SET_ERROR(SEQUENCE, 0);
61                return (NULL);
62        }
63
64        elfclass = e->e_class;
65
66        assert(elfclass == ELFCLASS32 || elfclass == ELFCLASS64);
67
68        if (elfclass == ELFCLASS32) {
69                sh_type   = s->s_shdr.s_shdr32.sh_type;
70                sh_offset = (uint64_t) s->s_shdr.s_shdr32.sh_offset;
71                sh_size   = (uint64_t) s->s_shdr.s_shdr32.sh_size;
72                sh_align  = (uint64_t) s->s_shdr.s_shdr32.sh_addralign;
73        } else {
74                sh_type   = s->s_shdr.s_shdr64.sh_type;
75                sh_offset = s->s_shdr.s_shdr64.sh_offset;
76                sh_size   = s->s_shdr.s_shdr64.sh_size;
77                sh_align  = s->s_shdr.s_shdr64.sh_addralign;
78        }
79
80        if ((elftype = _libelf_xlate_shtype(sh_type)) < ELF_T_FIRST ||
81            elftype > ELF_T_LAST ||
82            sh_offset + sh_size > (uint64_t) e->e_rawsize) {
83                LIBELF_SET_ERROR(SECTION, 0);
84                return (NULL);
85        }
86
87        if ((fsz = (elfclass == ELFCLASS32 ? elf32_fsize : elf64_fsize)(elftype,
88                 (size_t) 1, e->e_version)) == 0) {
89                LIBELF_SET_ERROR(UNIMPL, 0);
90                return (NULL);
91        }
92
93
94        if (sh_size % fsz) {
95                LIBELF_SET_ERROR(SECTION, 0);
96                return (NULL);
97        }
98
99        count = sh_size / fsz;
100
101        msz = _libelf_msize(elftype, elfclass, e->e_version);
102
103        assert(msz > 0);
104
105        if ((dst = malloc(msz*count)) == NULL) {
106                LIBELF_SET_ERROR(RESOURCE, 0);
107                return (NULL);
108        }
109
110        if ((d = _libelf_allocate_data(s)) == NULL)
111                return (NULL);
112
113        d->d_buf     = dst;
114        d->d_off     = 0;
115        d->d_align   = sh_align;
116        d->d_size    = msz * count;
117        d->d_type    = elftype;
118        d->d_version = e->e_version;
119
120        d->d_flags  |= LIBELF_F_MALLOCED;
121        STAILQ_INSERT_TAIL(&s->s_data, d, d_next);
122
123        xlate = _libelf_get_translator(elftype, ELF_TOMEMORY, elfclass);
124        (*xlate)(d->d_buf, e->e_rawfile + sh_offset, count, e->e_byteorder !=
125            LIBELF_PRIVATE(byteorder));
126
127        return (d);
128}
129
130Elf_Data *
131elf_newdata(Elf_Scn *s)
132{
133        Elf *e;
134        Elf_Data *d;
135
136        if (s == NULL || (e = s->s_elf) == NULL ||
137            e->e_kind != ELF_K_ELF) {
138                LIBELF_SET_ERROR(ARGUMENT, 0);
139                return (NULL);
140        }
141
142        /*
143         * elf_newdata() has to append a data descriptor, so
144         * bring in existing section data if not already present.
145         */
146        if (e->e_rawfile && s->s_size > 0 && STAILQ_EMPTY(&s->s_data))
147                if (elf_getdata(s, NULL) == NULL)
148                        return (NULL);
149
150        if ((d = malloc(sizeof(Elf_Data))) == NULL) {
151                LIBELF_SET_ERROR(RESOURCE, errno);
152                return (NULL);
153        }
154
155        STAILQ_INSERT_TAIL(&s->s_data, d, d_next);
156        d->d_flags = 0;
157        d->d_scn = s;
158
159        d->d_align = 1;
160        d->d_buf = NULL;
161        d->d_off = (uint64_t) ~0;
162        d->d_size = 0;
163        d->d_type = ELF_T_BYTE;
164        d->d_version = LIBELF_PRIVATE(version);
165
166        (void) elf_flagscn(s, ELF_C_SET, ELF_F_DIRTY);
167
168        return (d);
169}
170
171/*
172 * Retrieve a data descriptor for raw (untranslated) data for section
173 * `s'.
174 */
175
176Elf_Data *
177elf_rawdata(Elf_Scn *s, Elf_Data *d)
178{
179        Elf *e;
180        int elf_class;
181        uint64_t sh_align, sh_offset, sh_size;
182
183        if (s == NULL || (e = s->s_elf) == NULL ||
184            e->e_kind != ELF_K_ELF || e->e_rawfile == NULL) {
185                LIBELF_SET_ERROR(ARGUMENT, 0);
186                return (NULL);
187        }
188
189        if (d == NULL && (d = STAILQ_FIRST(&s->s_rawdata)) != NULL)
190                return (d);
191
192        if (d != NULL)
193                return (STAILQ_NEXT(d, d_next));
194
195        elf_class = e->e_class;
196
197        assert(elf_class == ELFCLASS32 || elf_class == ELFCLASS64);
198
199        if (elf_class == ELFCLASS32) {
200                sh_offset = (uint64_t) s->s_shdr.s_shdr32.sh_offset;
201                sh_size   = (uint64_t) s->s_shdr.s_shdr32.sh_size;
202                sh_align  = (uint64_t) s->s_shdr.s_shdr32.sh_addralign;
203        } else {
204                sh_offset = s->s_shdr.s_shdr64.sh_offset;
205                sh_size   = s->s_shdr.s_shdr64.sh_size;
206                sh_align  = s->s_shdr.s_shdr64.sh_addralign;
207        }
208
209        if ((d = _libelf_allocate_data(s)) == NULL)
210                return (NULL);
211
212        d->d_buf     = e->e_rawfile + sh_offset;
213        d->d_off     = 0;
214        d->d_align   = sh_align;
215        d->d_size    = sh_size;
216        d->d_type    = ELF_T_BYTE;
217        d->d_version = e->e_version;
218
219        STAILQ_INSERT_TAIL(&s->s_rawdata, d, d_next);
220
221        return (d);
222}
223