xref: /netbsd-src/external/bsd/elftoolchain/dist/libelf/gelf_dyn.c (revision 82d56013d7b633d116a93943de88e08335357a7c)
1 /*	$NetBSD: gelf_dyn.c,v 1.3 2016/02/20 02:43:42 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 1.3 2016/02/20 02:43:42 christos Exp $");
43 ELFTC_VCSID("Id: gelf_dyn.c 3177 2015-03-30 18:19:41Z emaste ");
44 
45 GElf_Dyn *
46 gelf_getdyn(Elf_Data *ed, int ndx, GElf_Dyn *dst)
47 {
48 	int ec;
49 	Elf *e;
50 	size_t msz;
51 	Elf_Scn *scn;
52 	Elf32_Dyn *dyn32;
53 	Elf64_Dyn *dyn64;
54 	uint32_t sh_type;
55 	struct _Libelf_Data *d;
56 
57 	d = (struct _Libelf_Data *) ed;
58 
59 	if (d == NULL || ndx < 0 || dst == NULL ||
60 	    (scn = d->d_scn) == NULL ||
61 	    (e = scn->s_elf) == NULL) {
62 		LIBELF_SET_ERROR(ARGUMENT, 0);
63 		return (NULL);
64 	}
65 
66 	ec = e->e_class;
67 	assert(ec == ELFCLASS32 || ec == ELFCLASS64);
68 
69 	if (ec == ELFCLASS32)
70 		sh_type = scn->s_shdr.s_shdr32.sh_type;
71 	else
72 		sh_type = scn->s_shdr.s_shdr64.sh_type;
73 
74 	if (_libelf_xlate_shtype(sh_type) != ELF_T_DYN) {
75 		LIBELF_SET_ERROR(ARGUMENT, 0);
76 		return (NULL);
77 	}
78 
79 	msz = _libelf_msize(ELF_T_DYN, ec, e->e_version);
80 
81 	assert(msz > 0);
82 	assert(ndx >= 0);
83 
84 	if (msz * (size_t) ndx >= d->d_data.d_size) {
85 		LIBELF_SET_ERROR(ARGUMENT, 0);
86 		return (NULL);
87 	}
88 
89 	if (ec == ELFCLASS32) {
90 		dyn32 = (Elf32_Dyn *) d->d_data.d_buf + ndx;
91 
92 		dst->d_tag      = dyn32->d_tag;
93 		dst->d_un.d_val = (Elf64_Xword) dyn32->d_un.d_val;
94 
95 	} else {
96 
97 		dyn64 = (Elf64_Dyn *) d->d_data.d_buf + ndx;
98 
99 		*dst = *dyn64;
100 	}
101 
102 	return (dst);
103 }
104 
105 int
106 gelf_update_dyn(Elf_Data *ed, int ndx, GElf_Dyn *ds)
107 {
108 	int ec;
109 	Elf *e;
110 	size_t msz;
111 	Elf_Scn *scn;
112 	Elf32_Dyn *dyn32;
113 	Elf64_Dyn *dyn64;
114 	uint32_t sh_type;
115 	struct _Libelf_Data *d;
116 
117 	d = (struct _Libelf_Data *) ed;
118 
119 	if (d == NULL || ndx < 0 || ds == NULL ||
120 	    (scn = d->d_scn) == NULL ||
121 	    (e = scn->s_elf) == NULL) {
122 		LIBELF_SET_ERROR(ARGUMENT, 0);
123 		return (0);
124 	}
125 
126 	ec = e->e_class;
127 	assert(ec == ELFCLASS32 || ec == ELFCLASS64);
128 
129 	if (ec == ELFCLASS32)
130 		sh_type = scn->s_shdr.s_shdr32.sh_type;
131 	else
132 		sh_type = scn->s_shdr.s_shdr64.sh_type;
133 
134 	if (_libelf_xlate_shtype(sh_type) != ELF_T_DYN) {
135 		LIBELF_SET_ERROR(ARGUMENT, 0);
136 		return (0);
137 	}
138 
139 	msz = _libelf_msize(ELF_T_DYN, ec, e->e_version);
140 
141 	assert(msz > 0);
142 	assert(ndx >= 0);
143 
144 	if (msz * (size_t) ndx >= d->d_data.d_size) {
145 		LIBELF_SET_ERROR(ARGUMENT, 0);
146 		return (0);
147 	}
148 
149 	if (ec == ELFCLASS32) {
150 		dyn32 = (Elf32_Dyn *) d->d_data.d_buf + ndx;
151 
152 		LIBELF_COPY_S32(dyn32, ds, d_tag);
153 		LIBELF_COPY_U32(dyn32, ds, d_un.d_val);
154 	} else {
155 		dyn64 = (Elf64_Dyn *) d->d_data.d_buf + ndx;
156 
157 		*dyn64 = *ds;
158 	}
159 
160 	return (1);
161 }
162