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("$Id$");
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  }