xref: /freebsd/contrib/elftoolchain/libelf/libelf_memory.c (revision 0b3105a37d7adcadcb720112fed4dc4e8040be99)
1 /*-
2  * Copyright (c) 2011 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 <ar.h>
28 #include <assert.h>
29 #include <string.h>
30 #include <libelf.h>
31 
32 #include "_libelf.h"
33 
34 ELFTC_VCSID("$Id: libelf_memory.c 3013 2014-03-23 06:16:59Z jkoshy $");
35 
36 /*
37  * Create an ELF descriptor for a memory image, optionally reporting
38  * parse errors.
39  */
40 
41 Elf *
42 _libelf_memory(unsigned char *image, size_t sz, int reporterror)
43 {
44 	Elf *e;
45 	int e_class;
46 	enum Elf_Error error;
47 	unsigned int e_byteorder, e_version;
48 
49 	assert(image != NULL);
50 	assert(sz > 0);
51 
52 	if ((e = _libelf_allocate_elf()) == NULL)
53 		return (NULL);
54 
55 	e->e_cmd = ELF_C_READ;
56 	e->e_rawfile = image;
57 	e->e_rawsize = sz;
58 
59 #undef	LIBELF_IS_ELF
60 #define	LIBELF_IS_ELF(P) ((P)[EI_MAG0] == ELFMAG0 && 		\
61 	(P)[EI_MAG1] == ELFMAG1 && (P)[EI_MAG2] == ELFMAG2 &&	\
62 	(P)[EI_MAG3] == ELFMAG3)
63 
64 	if (sz > EI_NIDENT && LIBELF_IS_ELF(image)) {
65 		e_byteorder = image[EI_DATA];
66 		e_class     = image[EI_CLASS];
67 		e_version   = image[EI_VERSION];
68 
69 		error = ELF_E_NONE;
70 
71 		if (e_version > EV_CURRENT)
72 			error = ELF_E_VERSION;
73 		else if ((e_byteorder != ELFDATA2LSB && e_byteorder !=
74  		    ELFDATA2MSB) || (e_class != ELFCLASS32 && e_class !=
75 		    ELFCLASS64))
76 			error = ELF_E_HEADER;
77 
78 		if (error != ELF_E_NONE) {
79 			if (reporterror) {
80 				LIBELF_PRIVATE(error) = LIBELF_ERROR(error, 0);
81 				(void) _libelf_release_elf(e);
82 				return (NULL);
83 			}
84 		} else {
85 			_libelf_init_elf(e, ELF_K_ELF);
86 
87 			e->e_byteorder = e_byteorder;
88 			e->e_class = e_class;
89 			e->e_version = e_version;
90 		}
91 	} else if (sz >= SARMAG &&
92 	    strncmp((const char *) image, ARMAG, (size_t) SARMAG) == 0)
93 		return (_libelf_ar_open(e, reporterror));
94 
95 	return (e);
96 }
97