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