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#include <sys/cdefs.h>
28__FBSDID("$FreeBSD$");
29
30#include <sys/limits.h>
31
32#include <assert.h>
33#include <gelf.h>
34
35#include "_libelf.h"
36
37GElf_Dyn *
38gelf_getdyn(Elf_Data *d, int ndx, GElf_Dyn *dst)
39{
40	int ec;
41	Elf *e;
42	Elf_Scn *scn;
43	Elf32_Dyn *dyn32;
44	Elf64_Dyn *dyn64;
45	size_t msz;
46	uint32_t sh_type;
47
48	if (d == NULL || ndx < 0 || dst == NULL ||
49	    (scn = d->d_scn) == NULL ||
50	    (e = scn->s_elf) == NULL) {
51		LIBELF_SET_ERROR(ARGUMENT, 0);
52		return (NULL);
53	}
54
55	ec = e->e_class;
56	assert(ec == ELFCLASS32 || ec == ELFCLASS64);
57
58	if (ec == ELFCLASS32)
59		sh_type = scn->s_shdr.s_shdr32.sh_type;
60	else
61		sh_type = scn->s_shdr.s_shdr64.sh_type;
62
63	if (_libelf_xlate_shtype(sh_type) != ELF_T_DYN) {
64		LIBELF_SET_ERROR(ARGUMENT, 0);
65		return (NULL);
66	}
67
68	msz = _libelf_msize(ELF_T_DYN, ec, e->e_version);
69
70	assert(msz > 0);
71
72	if (msz * ndx >= d->d_size) {
73		LIBELF_SET_ERROR(ARGUMENT, 0);
74		return (NULL);
75	}
76
77	if (ec == ELFCLASS32) {
78		dyn32 = (Elf32_Dyn *) d->d_buf + ndx;
79
80		dst->d_tag      = dyn32->d_tag;
81		dst->d_un.d_val = (Elf64_Xword) dyn32->d_un.d_val;
82
83	} else {
84
85		dyn64 = (Elf64_Dyn *) d->d_buf + ndx;
86
87		*dst = *dyn64;
88	}
89
90	return (dst);
91}
92
93int
94gelf_update_dyn(Elf_Data *d, int ndx, GElf_Dyn *ds)
95{
96	int ec;
97	Elf *e;
98	Elf_Scn *scn;
99	Elf32_Dyn *dyn32;
100	Elf64_Dyn *dyn64;
101	size_t msz;
102	uint32_t sh_type;
103
104	if (d == NULL || ndx < 0 || ds == NULL ||
105	    (scn = d->d_scn) == NULL ||
106	    (e = scn->s_elf) == NULL) {
107		LIBELF_SET_ERROR(ARGUMENT, 0);
108		return (0);
109	}
110
111	ec = e->e_class;
112	assert(ec == ELFCLASS32 || ec == ELFCLASS64);
113
114	if (ec == ELFCLASS32)
115		sh_type = scn->s_shdr.s_shdr32.sh_type;
116	else
117		sh_type = scn->s_shdr.s_shdr64.sh_type;
118
119	if (_libelf_xlate_shtype(sh_type) != ELF_T_DYN) {
120		LIBELF_SET_ERROR(ARGUMENT, 0);
121		return (0);
122	}
123
124	msz = _libelf_msize(ELF_T_DYN, ec, e->e_version);
125	assert(msz > 0);
126
127	if (msz * ndx >= d->d_size) {
128		LIBELF_SET_ERROR(ARGUMENT, 0);
129		return (0);
130	}
131
132	if (ec == ELFCLASS32) {
133		dyn32 = (Elf32_Dyn *) d->d_buf + ndx;
134
135		LIBELF_COPY_S32(dyn32, ds, d_tag);
136		LIBELF_COPY_U32(dyn32, ds, d_un.d_val);
137	} else {
138		dyn64 = (Elf64_Dyn *) d->d_buf + ndx;
139
140		*dyn64 = *ds;
141	}
142
143	return (1);
144}
145