1/*	$NetBSD: gelf_rela.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_rela.c,v 1.5 2024/03/03 17:37:34 christos Exp $");
43ELFTC_VCSID("Id: gelf_rela.c 3977 2022-05-01 06:45:34Z jkoshy");
44
45GElf_Rela *
46gelf_getrela(Elf_Data *ed, int ndx, GElf_Rela *dst)
47{
48	int ec;
49	Elf *e;
50	size_t msz;
51	Elf_Scn *scn;
52	uint32_t sh_type;
53	Elf32_Rela *rela32;
54	Elf64_Rela *rela64;
55	struct _Libelf_Data *d;
56
57	d = (struct _Libelf_Data *) ed;
58
59	if (d == NULL || ndx < 0 || dst == NULL ||
60	    (scn = d->d_scn) == NULL ||
61	    (e = scn->s_elf) == NULL) {
62		LIBELF_SET_ERROR(ARGUMENT, 0);
63		return (NULL);
64	}
65
66	ec = e->e_class;
67	assert(ec == ELFCLASS32 || ec == ELFCLASS64);
68
69	if (ec == ELFCLASS32)
70		sh_type = scn->s_shdr.s_shdr32.sh_type;
71	else
72		sh_type = scn->s_shdr.s_shdr64.sh_type;
73
74	if (_libelf_xlate_shtype(sh_type) != ELF_T_RELA) {
75		LIBELF_SET_ERROR(ARGUMENT, 0);
76		return (NULL);
77	}
78
79	if ((msz = _libelf_msize(ELF_T_RELA, ec, e->e_version)) == 0)
80		return (NULL);
81
82	assert(ndx >= 0);
83
84	if (msz * (size_t) ndx >= d->d_data.d_size) {
85		LIBELF_SET_ERROR(ARGUMENT, 0);
86		return (NULL);
87	}
88
89	if (ec == ELFCLASS32) {
90		rela32 = (Elf32_Rela *) d->d_data.d_buf + ndx;
91
92		dst->r_offset = (Elf64_Addr) rela32->r_offset;
93		dst->r_info   = ELF64_R_INFO(
94		    (Elf64_Xword) ELF32_R_SYM(rela32->r_info),
95		    ELF32_R_TYPE(rela32->r_info));
96		dst->r_addend = (Elf64_Sxword) rela32->r_addend;
97
98	} else {
99
100		rela64 = (Elf64_Rela *) d->d_data.d_buf + ndx;
101
102		*dst = *rela64;
103	}
104
105	return (dst);
106}
107
108int
109gelf_update_rela(Elf_Data *ed, int ndx, GElf_Rela *dr)
110{
111	int ec;
112	Elf *e;
113	size_t msz;
114	Elf_Scn *scn;
115	uint32_t sh_type;
116	Elf32_Rela *rela32;
117	Elf64_Rela *rela64;
118	struct _Libelf_Data *d;
119
120	d = (struct _Libelf_Data *) ed;
121
122	if (d == NULL || ndx < 0 || dr == NULL ||
123	    (scn = d->d_scn) == NULL ||
124	    (e = scn->s_elf) == NULL) {
125		LIBELF_SET_ERROR(ARGUMENT, 0);
126		return (0);
127	}
128
129	ec = e->e_class;
130	assert(ec == ELFCLASS32 || ec == ELFCLASS64);
131
132	if (ec == ELFCLASS32)
133		sh_type = scn->s_shdr.s_shdr32.sh_type;
134	else
135		sh_type = scn->s_shdr.s_shdr64.sh_type;
136
137	if (_libelf_xlate_shtype(sh_type) != ELF_T_RELA) {
138		LIBELF_SET_ERROR(ARGUMENT, 0);
139		return (0);
140	}
141
142	if ((msz = _libelf_msize(ELF_T_RELA, ec, e->e_version)) == 0)
143		return (0);
144
145	assert(ndx >= 0);
146
147	if (msz * (size_t) ndx >= d->d_data.d_size) {
148		LIBELF_SET_ERROR(ARGUMENT, 0);
149		return (0);
150	}
151
152	if (ec == ELFCLASS32) {
153		rela32 = (Elf32_Rela *) d->d_data.d_buf + ndx;
154
155		LIBELF_COPY_U32(rela32, dr, r_offset);
156
157		if (ELF64_R_SYM(dr->r_info) > ELF32_R_SYM(~0U) ||
158		    ELF64_R_TYPE(dr->r_info) > ELF32_R_TYPE(~0U)) {
159			LIBELF_SET_ERROR(RANGE, 0);
160			return (0);
161		}
162		rela32->r_info = ELF32_R_INFO(
163			(Elf32_Word) ELF64_R_SYM(dr->r_info),
164			(Elf32_Word) ELF64_R_TYPE(dr->r_info));
165
166		LIBELF_COPY_S32(rela32, dr, r_addend);
167	} else {
168		rela64 = (Elf64_Rela *) d->d_data.d_buf + ndx;
169
170		*rela64 = *dr;
171	}
172
173	return (1);
174}
175