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
34 ELFTC_VCSID("$Id: gelf_dyn.c 3177 2015-03-30 18:19:41Z emaste $");
35
36 GElf_Dyn *
gelf_getdyn(Elf_Data * ed,int ndx,GElf_Dyn * dst)37 gelf_getdyn(Elf_Data *ed, int ndx, GElf_Dyn *dst)
38 {
39 int ec;
40 Elf *e;
41 size_t msz;
42 Elf_Scn *scn;
43 Elf32_Dyn *dyn32;
44 Elf64_Dyn *dyn64;
45 uint32_t sh_type;
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_DYN) {
66 LIBELF_SET_ERROR(ARGUMENT, 0);
67 return (NULL);
68 }
69
70 msz = _libelf_msize(ELF_T_DYN, ec, e->e_version);
71
72 assert(msz > 0);
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 dyn32 = (Elf32_Dyn *) d->d_data.d_buf + ndx;
82
83 dst->d_tag = dyn32->d_tag;
84 dst->d_un.d_val = (Elf64_Xword) dyn32->d_un.d_val;
85
86 } else {
87
88 dyn64 = (Elf64_Dyn *) d->d_data.d_buf + ndx;
89
90 *dst = *dyn64;
91 }
92
93 return (dst);
94 }
95
96 int
gelf_update_dyn(Elf_Data * ed,int ndx,GElf_Dyn * ds)97 gelf_update_dyn(Elf_Data *ed, int ndx, GElf_Dyn *ds)
98 {
99 int ec;
100 Elf *e;
101 size_t msz;
102 Elf_Scn *scn;
103 Elf32_Dyn *dyn32;
104 Elf64_Dyn *dyn64;
105 uint32_t sh_type;
106 struct _Libelf_Data *d;
107
108 d = (struct _Libelf_Data *) ed;
109
110 if (d == NULL || ndx < 0 || ds == NULL ||
111 (scn = d->d_scn) == NULL ||
112 (e = scn->s_elf) == NULL) {
113 LIBELF_SET_ERROR(ARGUMENT, 0);
114 return (0);
115 }
116
117 ec = e->e_class;
118 assert(ec == ELFCLASS32 || ec == ELFCLASS64);
119
120 if (ec == ELFCLASS32)
121 sh_type = scn->s_shdr.s_shdr32.sh_type;
122 else
123 sh_type = scn->s_shdr.s_shdr64.sh_type;
124
125 if (_libelf_xlate_shtype(sh_type) != ELF_T_DYN) {
126 LIBELF_SET_ERROR(ARGUMENT, 0);
127 return (0);
128 }
129
130 msz = _libelf_msize(ELF_T_DYN, ec, e->e_version);
131
132 assert(msz > 0);
133 assert(ndx >= 0);
134
135 if (msz * (size_t) ndx >= d->d_data.d_size) {
136 LIBELF_SET_ERROR(ARGUMENT, 0);
137 return (0);
138 }
139
140 if (ec == ELFCLASS32) {
141 dyn32 = (Elf32_Dyn *) d->d_data.d_buf + ndx;
142
143 LIBELF_COPY_S32(dyn32, ds, d_tag);
144 LIBELF_COPY_U32(dyn32, ds, d_un.d_val);
145 } else {
146 dyn64 = (Elf64_Dyn *) d->d_data.d_buf + ndx;
147
148 *dyn64 = *ds;
149 }
150
151 return (1);
152 }
153