xref: /freebsd/contrib/file/src/elfclass.h (revision ce6a89e27cd190313be39bb479880aeda4778436)
1 /*
2  * Copyright (c) Christos Zoulas 2008.
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 immediately at the beginning of the file, without modification,
10  *    this list of conditions, and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
19  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 	if (nbytes <= sizeof(elfhdr))
28 		return 0;
29 
30 	u.l = 1;
31 	(void)memcpy(&elfhdr, buf, sizeof elfhdr);
32 	swap = (u.c[sizeof(int32_t) - 1] + 1) != elfhdr.e_ident[EI_DATA];
33 
34 	type = elf_getu16(swap, elfhdr.e_type);
35 	notecount = ms->elf_notes_max;
36 	switch (type) {
37 #ifdef ELFCORE
38 	case ET_CORE:
39 		phnum = elf_getu16(swap, elfhdr.e_phnum);
40 		if (phnum > ms->elf_phnum_max)
41 			return toomany(ms, "program headers", phnum);
42 		flags |= FLAGS_IS_CORE;
43 		if (dophn_core(ms, clazz, swap, fd,
44 		    CAST(off_t, elf_getu(swap, elfhdr.e_phoff)), phnum,
45 		    CAST(size_t, elf_getu16(swap, elfhdr.e_phentsize)),
46 		    fsize, &flags, &notecount) == -1)
47 			return -1;
48 		break;
49 #endif
50 	case ET_EXEC:
51 	case ET_DYN:
52 		phnum = elf_getu16(swap, elfhdr.e_phnum);
53 		if (phnum > ms->elf_phnum_max)
54 			return toomany(ms, "program", phnum);
55 		shnum = elf_getu16(swap, elfhdr.e_shnum);
56 		if (shnum > ms->elf_shnum_max)
57 			return toomany(ms, "section", shnum);
58 		if (dophn_exec(ms, clazz, swap, fd,
59 		    CAST(off_t, elf_getu(swap, elfhdr.e_phoff)), phnum,
60 		    CAST(size_t, elf_getu16(swap, elfhdr.e_phentsize)),
61 		    fsize, shnum, &flags, &notecount) == -1)
62 			return -1;
63 		/*FALLTHROUGH*/
64 	case ET_REL:
65 		shnum = elf_getu16(swap, elfhdr.e_shnum);
66 		if (shnum > ms->elf_shnum_max)
67 			return toomany(ms, "section headers", shnum);
68 		if (doshn(ms, clazz, swap, fd,
69 		    CAST(off_t, elf_getu(swap, elfhdr.e_shoff)), shnum,
70 		    CAST(size_t, elf_getu16(swap, elfhdr.e_shentsize)),
71 		    fsize, elf_getu16(swap, elfhdr.e_machine),
72 		    CAST(int, elf_getu16(swap, elfhdr.e_shstrndx)),
73 		    &flags, &notecount) == -1)
74 			return -1;
75 		break;
76 
77 	default:
78 		break;
79 	}
80 	if (notecount == 0)
81 		return toomany(ms, "notes", ms->elf_notes_max);
82 	return 1;
83