1 /* $NetBSD: gelf_dyn.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_dyn.c,v 1.5 2024/03/03 17:37:34 christos Exp $");
43
44 GElf_Dyn *
gelf_getdyn(Elf_Data * ed,int ndx,GElf_Dyn * dst)45 gelf_getdyn(Elf_Data *ed, int ndx, GElf_Dyn *dst)
46 {
47 int ec;
48 Elf *e;
49 size_t msz;
50 Elf_Scn *scn;
51 Elf32_Dyn *dyn32;
52 Elf64_Dyn *dyn64;
53 uint32_t sh_type;
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_DYN) {
74 LIBELF_SET_ERROR(ARGUMENT, 0);
75 return (NULL);
76 }
77
78 if ((msz = _libelf_msize(ELF_T_DYN, 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 dyn32 = (Elf32_Dyn *) d->d_data.d_buf + ndx;
90
91 dst->d_tag = dyn32->d_tag;
92 dst->d_un.d_val = (Elf64_Xword) dyn32->d_un.d_val;
93
94 } else {
95
96 dyn64 = (Elf64_Dyn *) d->d_data.d_buf + ndx;
97
98 *dst = *dyn64;
99 }
100
101 return (dst);
102 }
103
104 int
gelf_update_dyn(Elf_Data * ed,int ndx,GElf_Dyn * ds)105 gelf_update_dyn(Elf_Data *ed, int ndx, GElf_Dyn *ds)
106 {
107 int ec;
108 Elf *e;
109 size_t msz;
110 Elf_Scn *scn;
111 Elf32_Dyn *dyn32;
112 Elf64_Dyn *dyn64;
113 uint32_t sh_type;
114 struct _Libelf_Data *d;
115
116 d = (struct _Libelf_Data *) ed;
117
118 if (d == NULL || ndx < 0 || ds == NULL ||
119 (scn = d->d_scn) == NULL ||
120 (e = scn->s_elf) == NULL) {
121 LIBELF_SET_ERROR(ARGUMENT, 0);
122 return (0);
123 }
124
125 ec = e->e_class;
126 assert(ec == ELFCLASS32 || ec == ELFCLASS64);
127
128 if (ec == ELFCLASS32)
129 sh_type = scn->s_shdr.s_shdr32.sh_type;
130 else
131 sh_type = scn->s_shdr.s_shdr64.sh_type;
132
133 if (_libelf_xlate_shtype(sh_type) != ELF_T_DYN) {
134 LIBELF_SET_ERROR(ARGUMENT, 0);
135 return (0);
136 }
137
138 if ((msz = _libelf_msize(ELF_T_DYN, ec, e->e_version)) == 0)
139 return (0);
140
141 assert(ndx >= 0);
142
143 if (msz * (size_t) ndx >= d->d_data.d_size) {
144 LIBELF_SET_ERROR(ARGUMENT, 0);
145 return (0);
146 }
147
148 if (ec == ELFCLASS32) {
149 dyn32 = (Elf32_Dyn *) d->d_data.d_buf + ndx;
150
151 LIBELF_COPY_S32(dyn32, ds, d_tag);
152 LIBELF_COPY_U32(dyn32, ds, d_un.d_val);
153 } else {
154 dyn64 = (Elf64_Dyn *) d->d_data.d_buf + ndx;
155
156 *dyn64 = *ds;
157 }
158
159 return (1);
160 }
161