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