xref: /openbsd/lib/libelf/gelf_ehdr.c (revision a1b5ec25)
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 <libelf.h>
30 #include <limits.h>
31 #include <stdint.h>
32 #include <string.h>
33 
34 #include "_libelf.h"
35 
36 ELFTC_VCSID("$Id: gelf_ehdr.c,v 1.1 2019/02/01 05:27:37 jsg Exp $");
37 
38 Elf32_Ehdr *
elf32_getehdr(Elf * e)39 elf32_getehdr(Elf *e)
40 {
41 	return (_libelf_ehdr(e, ELFCLASS32, 0));
42 }
43 
44 Elf64_Ehdr *
elf64_getehdr(Elf * e)45 elf64_getehdr(Elf *e)
46 {
47 	return (_libelf_ehdr(e, ELFCLASS64, 0));
48 }
49 
50 GElf_Ehdr *
gelf_getehdr(Elf * e,GElf_Ehdr * d)51 gelf_getehdr(Elf *e, GElf_Ehdr *d)
52 {
53 	int ec;
54 	Elf32_Ehdr *eh32;
55 	Elf64_Ehdr *eh64;
56 
57 	if (d == NULL || e == NULL ||
58 	    ((ec = e->e_class) != ELFCLASS32 && ec != ELFCLASS64)) {
59 		LIBELF_SET_ERROR(ARGUMENT, 0);
60 		return (NULL);
61 	}
62 
63 	if (ec == ELFCLASS32) {
64 		if ((eh32 = _libelf_ehdr(e, ELFCLASS32, 0)) == NULL)
65 			return (NULL);
66 
67 		(void) memcpy(d->e_ident, eh32->e_ident,
68 		    sizeof(eh32->e_ident));
69 		d->e_type		= eh32->e_type;
70 		d->e_machine		= eh32->e_machine;
71 		d->e_version		= eh32->e_version;
72 		d->e_entry		= eh32->e_entry;
73 		d->e_phoff		= eh32->e_phoff;
74 		d->e_shoff		= eh32->e_shoff;
75 		d->e_flags		= eh32->e_flags;
76 		d->e_ehsize		= eh32->e_ehsize;
77 		d->e_phentsize		= eh32->e_phentsize;
78 		d->e_phnum		= eh32->e_phnum;
79 		d->e_shentsize		= eh32->e_shentsize;
80 		d->e_shnum		= eh32->e_shnum;
81 		d->e_shstrndx		= eh32->e_shstrndx;
82 
83 		return (d);
84 	}
85 
86 	assert(ec == ELFCLASS64);
87 
88 	if ((eh64 = _libelf_ehdr(e, ELFCLASS64, 0)) == NULL)
89 		return (NULL);
90 	*d = *eh64;
91 
92 	return (d);
93 }
94 
95 Elf32_Ehdr *
elf32_newehdr(Elf * e)96 elf32_newehdr(Elf *e)
97 {
98 	return (_libelf_ehdr(e, ELFCLASS32, 1));
99 }
100 
101 Elf64_Ehdr *
elf64_newehdr(Elf * e)102 elf64_newehdr(Elf *e)
103 {
104 	return (_libelf_ehdr(e, ELFCLASS64, 1));
105 }
106 
107 void *
gelf_newehdr(Elf * e,int ec)108 gelf_newehdr(Elf *e, int ec)
109 {
110 	if (e != NULL &&
111 	    (ec == ELFCLASS32 || ec == ELFCLASS64))
112 		return (_libelf_ehdr(e, ec, 1));
113 
114 	LIBELF_SET_ERROR(ARGUMENT, 0);
115 	return (NULL);
116 }
117 
118 int
gelf_update_ehdr(Elf * e,GElf_Ehdr * s)119 gelf_update_ehdr(Elf *e, GElf_Ehdr *s)
120 {
121 	int ec;
122 	void *ehdr;
123 	Elf32_Ehdr *eh32;
124 	Elf64_Ehdr *eh64;
125 
126 	if (s== NULL || e == NULL || e->e_kind != ELF_K_ELF ||
127 	    ((ec = e->e_class) != ELFCLASS32 && ec != ELFCLASS64)) {
128 		LIBELF_SET_ERROR(ARGUMENT, 0);
129 		return (0);
130 	}
131 
132 	if (e->e_cmd == ELF_C_READ) {
133 		LIBELF_SET_ERROR(MODE, 0);
134 		return (0);
135 	}
136 
137 	if ((ehdr = _libelf_ehdr(e, ec, 0)) == NULL)
138 		return (0);
139 
140 	(void) elf_flagehdr(e, ELF_C_SET, ELF_F_DIRTY);
141 
142 	if (ec == ELFCLASS64) {
143 		eh64 = (Elf64_Ehdr *) ehdr;
144 		*eh64 = *s;
145 		return (1);
146 	}
147 
148 	eh32 = (Elf32_Ehdr *) ehdr;
149 
150 	(void) memcpy(eh32->e_ident, s->e_ident, sizeof(eh32->e_ident));
151 
152 	eh32->e_type      = s->e_type;
153 	eh32->e_machine   = s->e_machine;
154 	eh32->e_version   = s->e_version;
155 	LIBELF_COPY_U32(eh32, s, e_entry);
156 	LIBELF_COPY_U32(eh32, s, e_phoff);
157 	LIBELF_COPY_U32(eh32, s, e_shoff);
158 	eh32->e_flags     = s->e_flags;
159 	eh32->e_ehsize    = s->e_ehsize;
160 	eh32->e_phentsize = s->e_phentsize;
161 	eh32->e_phnum     = s->e_phnum;
162 	eh32->e_shentsize = s->e_shentsize;
163 	eh32->e_shnum     = s->e_shnum;
164 	eh32->e_shstrndx  = s->e_shstrndx;
165 
166 	return (1);
167 }
168