1/*	$NetBSD: gelf_dyn.c,v 1.5 2024/03/03 17:37:34 christos Exp $	*/
2
3/*-
4 * Copyright (c) 2006,2008 Joseph Koshy
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29#if HAVE_NBTOOL_CONFIG_H
30# include "nbtool_config.h"
31#endif
32
33#include <sys/cdefs.h>
34
35#include <assert.h>
36#include <gelf.h>
37#include <limits.h>
38#include <stdint.h>
39
40#include "_libelf.h"
41
42__RCSID("$NetBSD: gelf_dyn.c,v 1.5 2024/03/03 17:37:34 christos Exp $");
43
44GElf_Dyn *
45gelf_getdyn(Elf_Data *ed, int ndx, GElf_Dyn *dst)
46{
47	int ec;
48	Elf *e;
49	size_t msz;
50	Elf_Scn *scn;
51	Elf32_Dyn *dyn32;
52	Elf64_Dyn *dyn64;
53	uint32_t sh_type;
54	struct _Libelf_Data *d;
55
56	d = (struct _Libelf_Data *) ed;
57
58	if (d == NULL || ndx < 0 || dst == NULL ||
59	    (scn = d->d_scn) == NULL ||
60	    (e = scn->s_elf) == NULL) {
61		LIBELF_SET_ERROR(ARGUMENT, 0);
62		return (NULL);
63	}
64
65	ec = e->e_class;
66	assert(ec == ELFCLASS32 || ec == ELFCLASS64);
67
68	if (ec == ELFCLASS32)
69		sh_type = scn->s_shdr.s_shdr32.sh_type;
70	else
71		sh_type = scn->s_shdr.s_shdr64.sh_type;
72
73	if (_libelf_xlate_shtype(sh_type) != ELF_T_DYN) {
74		LIBELF_SET_ERROR(ARGUMENT, 0);
75		return (NULL);
76	}
77
78	if ((msz = _libelf_msize(ELF_T_DYN, ec, e->e_version)) == 0)
79		return (NULL);
80
81	assert(ndx >= 0);
82
83	if (msz * (size_t) ndx >= d->d_data.d_size) {
84		LIBELF_SET_ERROR(ARGUMENT, 0);
85		return (NULL);
86	}
87
88	if (ec == ELFCLASS32) {
89		dyn32 = (Elf32_Dyn *) d->d_data.d_buf + ndx;
90
91		dst->d_tag      = dyn32->d_tag;
92		dst->d_un.d_val = (Elf64_Xword) dyn32->d_un.d_val;
93
94	} else {
95
96		dyn64 = (Elf64_Dyn *) d->d_data.d_buf + ndx;
97
98		*dst = *dyn64;
99	}
100
101	return (dst);
102}
103
104int
105gelf_update_dyn(Elf_Data *ed, int ndx, GElf_Dyn *ds)
106{
107	int ec;
108	Elf *e;
109	size_t msz;
110	Elf_Scn *scn;
111	Elf32_Dyn *dyn32;
112	Elf64_Dyn *dyn64;
113	uint32_t sh_type;
114	struct _Libelf_Data *d;
115
116	d = (struct _Libelf_Data *) ed;
117
118	if (d == NULL || ndx < 0 || ds == NULL ||
119	    (scn = d->d_scn) == NULL ||
120	    (e = scn->s_elf) == NULL) {
121		LIBELF_SET_ERROR(ARGUMENT, 0);
122		return (0);
123	}
124
125	ec = e->e_class;
126	assert(ec == ELFCLASS32 || ec == ELFCLASS64);
127
128	if (ec == ELFCLASS32)
129		sh_type = scn->s_shdr.s_shdr32.sh_type;
130	else
131		sh_type = scn->s_shdr.s_shdr64.sh_type;
132
133	if (_libelf_xlate_shtype(sh_type) != ELF_T_DYN) {
134		LIBELF_SET_ERROR(ARGUMENT, 0);
135		return (0);
136	}
137
138	if ((msz = _libelf_msize(ELF_T_DYN, ec, e->e_version)) == 0)
139		return (0);
140
141	assert(ndx >= 0);
142
143	if (msz * (size_t) ndx >= d->d_data.d_size) {
144		LIBELF_SET_ERROR(ARGUMENT, 0);
145		return (0);
146	}
147
148	if (ec == ELFCLASS32) {
149		dyn32 = (Elf32_Dyn *) d->d_data.d_buf + ndx;
150
151		LIBELF_COPY_S32(dyn32, ds, d_tag);
152		LIBELF_COPY_U32(dyn32, ds, d_un.d_val);
153	} else {
154		dyn64 = (Elf64_Dyn *) d->d_data.d_buf + ndx;
155
156		*dyn64 = *ds;
157	}
158
159	return (1);
160}
161