1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2020 The FreeBSD Foundation
5 *
6 * This software was developed by Tiger Gao under sponsorship from
7 * the FreeBSD Foundation.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions are
11 * met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in
16 * the documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 */
30
31 #include <gelf.h>
32 #include <libelf.h>
33
34 #include "_libelf.h"
35
36 void *
_libelf_getchdr(Elf_Scn * s,int ec)37 _libelf_getchdr(Elf_Scn *s, int ec)
38 {
39 Elf *e;
40 void *sh;
41 Elf32_Shdr *sh32;
42 Elf64_Shdr *sh64;
43
44 sh32 = NULL;
45 sh64 = NULL;
46
47 if (s == NULL || (e = s->s_elf) == NULL || e->e_kind != ELF_K_ELF) {
48 LIBELF_SET_ERROR(ARGUMENT, 0);
49 return (NULL);
50 }
51
52 if (ec == ELFCLASSNONE) {
53 ec = e->e_class;
54 } else if (ec != e->e_class) {
55 LIBELF_SET_ERROR(CLASS, 0);
56 return (NULL);
57 }
58
59 if ((sh = _libelf_getshdr(s, ec)) == NULL) {
60 LIBELF_SET_ERROR(HEADER, 0);
61 return (NULL);
62 }
63
64 if (ec == ELFCLASS32) {
65 sh32 = (Elf32_Shdr *)sh;
66 if ((sh32->sh_flags & SHF_ALLOC) != 0) {
67 LIBELF_SET_ERROR(INVALID_SECTION_FLAGS, 0);
68 return (NULL);
69 }
70
71 if (sh32->sh_type == SHT_NULL || sh32->sh_type == SHT_NOBITS) {
72 LIBELF_SET_ERROR(INVALID_SECTION_TYPE, 0);
73 return (NULL);
74 }
75
76 if ((sh32->sh_flags & SHF_COMPRESSED) == 0) {
77 LIBELF_SET_ERROR(NOT_COMPRESSED, 0);
78 return (NULL);
79 }
80 } else {
81 sh64 = (Elf64_Shdr *)sh;
82 if ((sh64->sh_flags & SHF_ALLOC) != 0) {
83 LIBELF_SET_ERROR(INVALID_SECTION_FLAGS, 0);
84 return (NULL);
85 }
86
87 if (sh64->sh_type == SHT_NULL || sh64->sh_type == SHT_NOBITS) {
88 LIBELF_SET_ERROR(INVALID_SECTION_TYPE, 0);
89 return (NULL);
90 }
91
92 if ((sh64->sh_flags & SHF_COMPRESSED) == 0) {
93 LIBELF_SET_ERROR(NOT_COMPRESSED, 0);
94 return (NULL);
95 }
96 }
97
98 Elf_Data *d = elf_getdata(s, NULL);
99
100 if (!d)
101 return (NULL);
102
103 return ((void *)d->d_buf);
104 }
105