xref: /openbsd-src/lib/libelf/gelf_ehdr.c (revision a1b5ec256a03e12d667837fca8bf42f20675916f)
1*a1b5ec25Sjsg /*-
2*a1b5ec25Sjsg  * Copyright (c) 2006,2008 Joseph Koshy
3*a1b5ec25Sjsg  * All rights reserved.
4*a1b5ec25Sjsg  *
5*a1b5ec25Sjsg  * Redistribution and use in source and binary forms, with or without
6*a1b5ec25Sjsg  * modification, are permitted provided that the following conditions
7*a1b5ec25Sjsg  * are met:
8*a1b5ec25Sjsg  * 1. Redistributions of source code must retain the above copyright
9*a1b5ec25Sjsg  *    notice, this list of conditions and the following disclaimer.
10*a1b5ec25Sjsg  * 2. Redistributions in binary form must reproduce the above copyright
11*a1b5ec25Sjsg  *    notice, this list of conditions and the following disclaimer in the
12*a1b5ec25Sjsg  *    documentation and/or other materials provided with the distribution.
13*a1b5ec25Sjsg  *
14*a1b5ec25Sjsg  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15*a1b5ec25Sjsg  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16*a1b5ec25Sjsg  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17*a1b5ec25Sjsg  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18*a1b5ec25Sjsg  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19*a1b5ec25Sjsg  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20*a1b5ec25Sjsg  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21*a1b5ec25Sjsg  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22*a1b5ec25Sjsg  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23*a1b5ec25Sjsg  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24*a1b5ec25Sjsg  * SUCH DAMAGE.
25*a1b5ec25Sjsg  */
26*a1b5ec25Sjsg 
27*a1b5ec25Sjsg #include <assert.h>
28*a1b5ec25Sjsg #include <gelf.h>
29*a1b5ec25Sjsg #include <libelf.h>
30*a1b5ec25Sjsg #include <limits.h>
31*a1b5ec25Sjsg #include <stdint.h>
32*a1b5ec25Sjsg #include <string.h>
33*a1b5ec25Sjsg 
34*a1b5ec25Sjsg #include "_libelf.h"
35*a1b5ec25Sjsg 
36*a1b5ec25Sjsg ELFTC_VCSID("$Id: gelf_ehdr.c,v 1.1 2019/02/01 05:27:37 jsg Exp $");
37*a1b5ec25Sjsg 
38*a1b5ec25Sjsg Elf32_Ehdr *
elf32_getehdr(Elf * e)39*a1b5ec25Sjsg elf32_getehdr(Elf *e)
40*a1b5ec25Sjsg {
41*a1b5ec25Sjsg 	return (_libelf_ehdr(e, ELFCLASS32, 0));
42*a1b5ec25Sjsg }
43*a1b5ec25Sjsg 
44*a1b5ec25Sjsg Elf64_Ehdr *
elf64_getehdr(Elf * e)45*a1b5ec25Sjsg elf64_getehdr(Elf *e)
46*a1b5ec25Sjsg {
47*a1b5ec25Sjsg 	return (_libelf_ehdr(e, ELFCLASS64, 0));
48*a1b5ec25Sjsg }
49*a1b5ec25Sjsg 
50*a1b5ec25Sjsg GElf_Ehdr *
gelf_getehdr(Elf * e,GElf_Ehdr * d)51*a1b5ec25Sjsg gelf_getehdr(Elf *e, GElf_Ehdr *d)
52*a1b5ec25Sjsg {
53*a1b5ec25Sjsg 	int ec;
54*a1b5ec25Sjsg 	Elf32_Ehdr *eh32;
55*a1b5ec25Sjsg 	Elf64_Ehdr *eh64;
56*a1b5ec25Sjsg 
57*a1b5ec25Sjsg 	if (d == NULL || e == NULL ||
58*a1b5ec25Sjsg 	    ((ec = e->e_class) != ELFCLASS32 && ec != ELFCLASS64)) {
59*a1b5ec25Sjsg 		LIBELF_SET_ERROR(ARGUMENT, 0);
60*a1b5ec25Sjsg 		return (NULL);
61*a1b5ec25Sjsg 	}
62*a1b5ec25Sjsg 
63*a1b5ec25Sjsg 	if (ec == ELFCLASS32) {
64*a1b5ec25Sjsg 		if ((eh32 = _libelf_ehdr(e, ELFCLASS32, 0)) == NULL)
65*a1b5ec25Sjsg 			return (NULL);
66*a1b5ec25Sjsg 
67*a1b5ec25Sjsg 		(void) memcpy(d->e_ident, eh32->e_ident,
68*a1b5ec25Sjsg 		    sizeof(eh32->e_ident));
69*a1b5ec25Sjsg 		d->e_type		= eh32->e_type;
70*a1b5ec25Sjsg 		d->e_machine		= eh32->e_machine;
71*a1b5ec25Sjsg 		d->e_version		= eh32->e_version;
72*a1b5ec25Sjsg 		d->e_entry		= eh32->e_entry;
73*a1b5ec25Sjsg 		d->e_phoff		= eh32->e_phoff;
74*a1b5ec25Sjsg 		d->e_shoff		= eh32->e_shoff;
75*a1b5ec25Sjsg 		d->e_flags		= eh32->e_flags;
76*a1b5ec25Sjsg 		d->e_ehsize		= eh32->e_ehsize;
77*a1b5ec25Sjsg 		d->e_phentsize		= eh32->e_phentsize;
78*a1b5ec25Sjsg 		d->e_phnum		= eh32->e_phnum;
79*a1b5ec25Sjsg 		d->e_shentsize		= eh32->e_shentsize;
80*a1b5ec25Sjsg 		d->e_shnum		= eh32->e_shnum;
81*a1b5ec25Sjsg 		d->e_shstrndx		= eh32->e_shstrndx;
82*a1b5ec25Sjsg 
83*a1b5ec25Sjsg 		return (d);
84*a1b5ec25Sjsg 	}
85*a1b5ec25Sjsg 
86*a1b5ec25Sjsg 	assert(ec == ELFCLASS64);
87*a1b5ec25Sjsg 
88*a1b5ec25Sjsg 	if ((eh64 = _libelf_ehdr(e, ELFCLASS64, 0)) == NULL)
89*a1b5ec25Sjsg 		return (NULL);
90*a1b5ec25Sjsg 	*d = *eh64;
91*a1b5ec25Sjsg 
92*a1b5ec25Sjsg 	return (d);
93*a1b5ec25Sjsg }
94*a1b5ec25Sjsg 
95*a1b5ec25Sjsg Elf32_Ehdr *
elf32_newehdr(Elf * e)96*a1b5ec25Sjsg elf32_newehdr(Elf *e)
97*a1b5ec25Sjsg {
98*a1b5ec25Sjsg 	return (_libelf_ehdr(e, ELFCLASS32, 1));
99*a1b5ec25Sjsg }
100*a1b5ec25Sjsg 
101*a1b5ec25Sjsg Elf64_Ehdr *
elf64_newehdr(Elf * e)102*a1b5ec25Sjsg elf64_newehdr(Elf *e)
103*a1b5ec25Sjsg {
104*a1b5ec25Sjsg 	return (_libelf_ehdr(e, ELFCLASS64, 1));
105*a1b5ec25Sjsg }
106*a1b5ec25Sjsg 
107*a1b5ec25Sjsg void *
gelf_newehdr(Elf * e,int ec)108*a1b5ec25Sjsg gelf_newehdr(Elf *e, int ec)
109*a1b5ec25Sjsg {
110*a1b5ec25Sjsg 	if (e != NULL &&
111*a1b5ec25Sjsg 	    (ec == ELFCLASS32 || ec == ELFCLASS64))
112*a1b5ec25Sjsg 		return (_libelf_ehdr(e, ec, 1));
113*a1b5ec25Sjsg 
114*a1b5ec25Sjsg 	LIBELF_SET_ERROR(ARGUMENT, 0);
115*a1b5ec25Sjsg 	return (NULL);
116*a1b5ec25Sjsg }
117*a1b5ec25Sjsg 
118*a1b5ec25Sjsg int
gelf_update_ehdr(Elf * e,GElf_Ehdr * s)119*a1b5ec25Sjsg gelf_update_ehdr(Elf *e, GElf_Ehdr *s)
120*a1b5ec25Sjsg {
121*a1b5ec25Sjsg 	int ec;
122*a1b5ec25Sjsg 	void *ehdr;
123*a1b5ec25Sjsg 	Elf32_Ehdr *eh32;
124*a1b5ec25Sjsg 	Elf64_Ehdr *eh64;
125*a1b5ec25Sjsg 
126*a1b5ec25Sjsg 	if (s== NULL || e == NULL || e->e_kind != ELF_K_ELF ||
127*a1b5ec25Sjsg 	    ((ec = e->e_class) != ELFCLASS32 && ec != ELFCLASS64)) {
128*a1b5ec25Sjsg 		LIBELF_SET_ERROR(ARGUMENT, 0);
129*a1b5ec25Sjsg 		return (0);
130*a1b5ec25Sjsg 	}
131*a1b5ec25Sjsg 
132*a1b5ec25Sjsg 	if (e->e_cmd == ELF_C_READ) {
133*a1b5ec25Sjsg 		LIBELF_SET_ERROR(MODE, 0);
134*a1b5ec25Sjsg 		return (0);
135*a1b5ec25Sjsg 	}
136*a1b5ec25Sjsg 
137*a1b5ec25Sjsg 	if ((ehdr = _libelf_ehdr(e, ec, 0)) == NULL)
138*a1b5ec25Sjsg 		return (0);
139*a1b5ec25Sjsg 
140*a1b5ec25Sjsg 	(void) elf_flagehdr(e, ELF_C_SET, ELF_F_DIRTY);
141*a1b5ec25Sjsg 
142*a1b5ec25Sjsg 	if (ec == ELFCLASS64) {
143*a1b5ec25Sjsg 		eh64 = (Elf64_Ehdr *) ehdr;
144*a1b5ec25Sjsg 		*eh64 = *s;
145*a1b5ec25Sjsg 		return (1);
146*a1b5ec25Sjsg 	}
147*a1b5ec25Sjsg 
148*a1b5ec25Sjsg 	eh32 = (Elf32_Ehdr *) ehdr;
149*a1b5ec25Sjsg 
150*a1b5ec25Sjsg 	(void) memcpy(eh32->e_ident, s->e_ident, sizeof(eh32->e_ident));
151*a1b5ec25Sjsg 
152*a1b5ec25Sjsg 	eh32->e_type      = s->e_type;
153*a1b5ec25Sjsg 	eh32->e_machine   = s->e_machine;
154*a1b5ec25Sjsg 	eh32->e_version   = s->e_version;
155*a1b5ec25Sjsg 	LIBELF_COPY_U32(eh32, s, e_entry);
156*a1b5ec25Sjsg 	LIBELF_COPY_U32(eh32, s, e_phoff);
157*a1b5ec25Sjsg 	LIBELF_COPY_U32(eh32, s, e_shoff);
158*a1b5ec25Sjsg 	eh32->e_flags     = s->e_flags;
159*a1b5ec25Sjsg 	eh32->e_ehsize    = s->e_ehsize;
160*a1b5ec25Sjsg 	eh32->e_phentsize = s->e_phentsize;
161*a1b5ec25Sjsg 	eh32->e_phnum     = s->e_phnum;
162*a1b5ec25Sjsg 	eh32->e_shentsize = s->e_shentsize;
163*a1b5ec25Sjsg 	eh32->e_shnum     = s->e_shnum;
164*a1b5ec25Sjsg 	eh32->e_shstrndx  = s->e_shstrndx;
165*a1b5ec25Sjsg 
166*a1b5ec25Sjsg 	return (1);
167*a1b5ec25Sjsg }
168