1/*	$NetBSD: gelf_rel.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_rel.c,v 1.5 2024/03/03 17:37:34 christos Exp $");
43
44GElf_Rel *
45gelf_getrel(Elf_Data *ed, int ndx, GElf_Rel *dst)
46{
47	int ec;
48	Elf *e;
49	size_t msz;
50	Elf_Scn *scn;
51	uint32_t sh_type;
52	Elf32_Rel *rel32;
53	Elf64_Rel *rel64;
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_REL) {
74		LIBELF_SET_ERROR(ARGUMENT, 0);
75		return (NULL);
76	}
77
78	if ((msz = _libelf_msize(ELF_T_REL, 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		rel32 = (Elf32_Rel *) d->d_data.d_buf + ndx;
90
91		dst->r_offset = (Elf64_Addr) rel32->r_offset;
92		dst->r_info   = ELF64_R_INFO(
93		    (Elf64_Xword) ELF32_R_SYM(rel32->r_info),
94		    ELF32_R_TYPE(rel32->r_info));
95
96	} else {
97
98		rel64 = (Elf64_Rel *) d->d_data.d_buf + ndx;
99
100		*dst = *rel64;
101	}
102
103	return (dst);
104}
105
106int
107gelf_update_rel(Elf_Data *ed, int ndx, GElf_Rel *dr)
108{
109	int ec;
110	Elf *e;
111	size_t msz;
112	Elf_Scn *scn;
113	uint32_t sh_type;
114	Elf32_Rel *rel32;
115	Elf64_Rel *rel64;
116	struct _Libelf_Data *d;
117
118	d = (struct _Libelf_Data *) ed;
119
120	if (d == NULL || ndx < 0 || dr == NULL ||
121	    (scn = d->d_scn) == NULL ||
122	    (e = scn->s_elf) == NULL) {
123		LIBELF_SET_ERROR(ARGUMENT, 0);
124		return (0);
125	}
126
127	ec = e->e_class;
128	assert(ec == ELFCLASS32 || ec == ELFCLASS64);
129
130	if (ec == ELFCLASS32)
131		sh_type = scn->s_shdr.s_shdr32.sh_type;
132	else
133		sh_type = scn->s_shdr.s_shdr64.sh_type;
134
135	if (_libelf_xlate_shtype(sh_type) != ELF_T_REL) {
136		LIBELF_SET_ERROR(ARGUMENT, 0);
137		return (0);
138	}
139
140	if ((msz = _libelf_msize(ELF_T_REL, ec, e->e_version)) == 0)
141		return (0);
142
143	assert(ndx >= 0);
144
145	if (msz * (size_t) ndx >= d->d_data.d_size) {
146		LIBELF_SET_ERROR(ARGUMENT, 0);
147		return (0);
148	}
149
150	if (ec == ELFCLASS32) {
151		rel32 = (Elf32_Rel *) d->d_data.d_buf + ndx;
152
153		LIBELF_COPY_U32(rel32, dr, r_offset);
154
155		if (ELF64_R_SYM(dr->r_info) > ELF32_R_SYM(~0U) ||
156		    ELF64_R_TYPE(dr->r_info) > ELF32_R_TYPE(~0U)) {
157			LIBELF_SET_ERROR(RANGE, 0);
158			return (0);
159		}
160		rel32->r_info = ELF32_R_INFO(
161			(Elf32_Word) ELF64_R_SYM(dr->r_info),
162			(Elf32_Word) ELF64_R_TYPE(dr->r_info));
163	} else {
164		rel64 = (Elf64_Rel *) d->d_data.d_buf + ndx;
165
166		*rel64 = *dr;
167	}
168
169	return (1);
170}
171