1/*-
2 * Copyright (c) 2006,2008 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 <assert.h>
28#include <gelf.h>
29#include <limits.h>
30#include <stdint.h>
31
32#include "_libelf.h"
33
34ELFTC_VCSID("$Id: gelf_sym.c 3732 2019-04-22 11:08:38Z jkoshy $");
35
36GElf_Sym *
37gelf_getsym(Elf_Data *ed, int ndx, GElf_Sym *dst)
38{
39	int ec;
40	Elf *e;
41	size_t msz;
42	Elf_Scn *scn;
43	uint32_t sh_type;
44	Elf32_Sym *sym32;
45	Elf64_Sym *sym64;
46	struct _Libelf_Data *d;
47
48	d = (struct _Libelf_Data *) ed;
49
50	if (d == NULL || ndx < 0 || dst == NULL ||
51	    (scn = d->d_scn) == NULL ||
52	    (e = scn->s_elf) == NULL) {
53		LIBELF_SET_ERROR(ARGUMENT, 0);
54		return (NULL);
55	}
56
57	ec = e->e_class;
58	assert(ec == ELFCLASS32 || ec == ELFCLASS64);
59
60	if (ec == ELFCLASS32)
61		sh_type = scn->s_shdr.s_shdr32.sh_type;
62	else
63		sh_type = scn->s_shdr.s_shdr64.sh_type;
64
65	if (_libelf_xlate_shtype(sh_type) != ELF_T_SYM) {
66		LIBELF_SET_ERROR(ARGUMENT, 0);
67		return (NULL);
68	}
69
70	if ((msz = _libelf_msize(ELF_T_SYM, ec, e->e_version)) == 0)
71		return (NULL);
72
73	assert(ndx >= 0);
74
75	if (msz * (size_t) ndx >= d->d_data.d_size) {
76		LIBELF_SET_ERROR(ARGUMENT, 0);
77		return (NULL);
78	}
79
80	if (ec == ELFCLASS32) {
81		sym32 = (Elf32_Sym *) d->d_data.d_buf + ndx;
82
83		dst->st_name  = sym32->st_name;
84		dst->st_value = (Elf64_Addr) sym32->st_value;
85		dst->st_size  = (Elf64_Xword) sym32->st_size;
86		dst->st_info  = sym32->st_info;
87		dst->st_other = sym32->st_other;
88		dst->st_shndx = sym32->st_shndx;
89	} else {
90		sym64 = (Elf64_Sym *) d->d_data.d_buf + ndx;
91
92		*dst = *sym64;
93	}
94
95	return (dst);
96}
97
98int
99gelf_update_sym(Elf_Data *ed, int ndx, GElf_Sym *gs)
100{
101	int ec;
102	Elf *e;
103	size_t msz;
104	Elf_Scn *scn;
105	uint32_t sh_type;
106	Elf32_Sym *sym32;
107	Elf64_Sym *sym64;
108	struct _Libelf_Data *d;
109
110	d = (struct _Libelf_Data *) ed;
111
112	if (d == NULL || ndx < 0 || gs == NULL ||
113	    (scn = d->d_scn) == NULL ||
114	    (e = scn->s_elf) == NULL) {
115		LIBELF_SET_ERROR(ARGUMENT, 0);
116		return (0);
117	}
118
119	ec = e->e_class;
120	assert(ec == ELFCLASS32 || ec == ELFCLASS64);
121
122	if (ec == ELFCLASS32)
123		sh_type = scn->s_shdr.s_shdr32.sh_type;
124	else
125		sh_type = scn->s_shdr.s_shdr64.sh_type;
126
127	if (_libelf_xlate_shtype(sh_type) != ELF_T_SYM) {
128		LIBELF_SET_ERROR(ARGUMENT, 0);
129		return (0);
130	}
131
132	if ((msz = _libelf_msize(ELF_T_SYM, ec, e->e_version)) == 0)
133		return (0);
134
135	assert(ndx >= 0);
136
137	if (msz * (size_t) ndx >= d->d_data.d_size) {
138		LIBELF_SET_ERROR(ARGUMENT, 0);
139		return (0);
140	}
141
142	if (ec == ELFCLASS32) {
143		sym32 = (Elf32_Sym *) d->d_data.d_buf + ndx;
144
145		sym32->st_name  = gs->st_name;
146		sym32->st_info  = gs->st_info;
147		sym32->st_other = gs->st_other;
148		sym32->st_shndx = gs->st_shndx;
149
150		LIBELF_COPY_U32(sym32, gs, st_value);
151		LIBELF_COPY_U32(sym32, gs, st_size);
152	} else {
153		sym64 = (Elf64_Sym *) d->d_data.d_buf + ndx;
154
155		*sym64 = *gs;
156	}
157
158	return (1);
159}
160