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 <sys/cdefs.h>
28
29 #include <assert.h>
30 #include <gelf.h>
31 #include <limits.h>
32
33 #include "_libelf.h"
34
35 ELFTC_VCSID("$Id$");
36
37 GElf_Dyn *
gelf_getdyn(Elf_Data * ed,int ndx,GElf_Dyn * dst)38 gelf_getdyn(Elf_Data *ed, int ndx, GElf_Dyn *dst)
39 {
40 int ec;
41 Elf *e;
42 size_t msz;
43 Elf_Scn *scn;
44 Elf32_Dyn *dyn32;
45 Elf64_Dyn *dyn64;
46 uint32_t sh_type;
47 struct _Libelf_Data *d;
48
49 d = (struct _Libelf_Data *) ed;
50
51 if (d == NULL || ndx < 0 || dst == NULL ||
52 (scn = d->d_scn) == NULL ||
53 (e = scn->s_elf) == NULL) {
54 LIBELF_SET_ERROR(ARGUMENT, 0);
55 return (NULL);
56 }
57
58 ec = e->e_class;
59 assert(ec == ELFCLASS32 || ec == ELFCLASS64);
60
61 if (ec == ELFCLASS32)
62 sh_type = scn->s_shdr.s_shdr32.sh_type;
63 else
64 sh_type = scn->s_shdr.s_shdr64.sh_type;
65
66 if (_libelf_xlate_shtype(sh_type) != ELF_T_DYN) {
67 LIBELF_SET_ERROR(ARGUMENT, 0);
68 return (NULL);
69 }
70
71 msz = _libelf_msize(ELF_T_DYN, ec, e->e_version);
72
73 assert(msz > 0);
74 assert(ndx >= 0);
75
76 if (msz * (size_t) ndx >= d->d_data.d_size) {
77 LIBELF_SET_ERROR(ARGUMENT, 0);
78 return (NULL);
79 }
80
81 if (ec == ELFCLASS32) {
82 dyn32 = (Elf32_Dyn *) d->d_data.d_buf + ndx;
83
84 dst->d_tag = dyn32->d_tag;
85 dst->d_un.d_val = (Elf64_Xword) dyn32->d_un.d_val;
86
87 } else {
88
89 dyn64 = (Elf64_Dyn *) d->d_data.d_buf + ndx;
90
91 *dst = *dyn64;
92 }
93
94 return (dst);
95 }
96
97 int
gelf_update_dyn(Elf_Data * ed,int ndx,GElf_Dyn * ds)98 gelf_update_dyn(Elf_Data *ed, int ndx, GElf_Dyn *ds)
99 {
100 int ec;
101 Elf *e;
102 size_t msz;
103 Elf_Scn *scn;
104 Elf32_Dyn *dyn32;
105 Elf64_Dyn *dyn64;
106 uint32_t sh_type;
107 struct _Libelf_Data *d;
108
109 d = (struct _Libelf_Data *) ed;
110
111 if (d == NULL || ndx < 0 || ds == NULL ||
112 (scn = d->d_scn) == NULL ||
113 (e = scn->s_elf) == NULL) {
114 LIBELF_SET_ERROR(ARGUMENT, 0);
115 return (0);
116 }
117
118 ec = e->e_class;
119 assert(ec == ELFCLASS32 || ec == ELFCLASS64);
120
121 if (ec == ELFCLASS32)
122 sh_type = scn->s_shdr.s_shdr32.sh_type;
123 else
124 sh_type = scn->s_shdr.s_shdr64.sh_type;
125
126 if (_libelf_xlate_shtype(sh_type) != ELF_T_DYN) {
127 LIBELF_SET_ERROR(ARGUMENT, 0);
128 return (0);
129 }
130
131 msz = _libelf_msize(ELF_T_DYN, ec, e->e_version);
132
133 assert(msz > 0);
134 assert(ndx >= 0);
135
136 if (msz * (size_t) ndx >= d->d_data.d_size) {
137 LIBELF_SET_ERROR(ARGUMENT, 0);
138 return (0);
139 }
140
141 if (ec == ELFCLASS32) {
142 dyn32 = (Elf32_Dyn *) d->d_data.d_buf + ndx;
143
144 LIBELF_COPY_S32(dyn32, ds, d_tag);
145 LIBELF_COPY_U32(dyn32, ds, d_un.d_val);
146 } else {
147 dyn64 = (Elf64_Dyn *) d->d_data.d_buf + ndx;
148
149 *dyn64 = *ds;
150 }
151
152 return (1);
153 }
154