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 <libelf.h>
29
30#include "_libelf.h"
31
32ELFTC_VCSID("$Id: libelf_extended.c,v 1.2 2019/03/19 02:31:35 jsg Exp $");
33
34/*
35 * Retrieve section #0, allocating a new section if needed.
36 */
37static Elf_Scn *
38_libelf_getscn0(Elf *e)
39{
40	Elf_Scn *s;
41
42	if ((s = STAILQ_FIRST(&e->e_u.e_elf.e_scn)) != NULL)
43		return (s);
44
45	return (_libelf_allocate_scn(e, (size_t) SHN_UNDEF));
46}
47
48int
49_libelf_setshnum(Elf *e, void *eh, int ec, size_t shnum)
50{
51	Elf_Scn *scn;
52
53	if (shnum >= SHN_LORESERVE) {
54		if ((scn = _libelf_getscn0(e)) == NULL)
55			return (0);
56
57		assert(scn->s_ndx == SHN_UNDEF);
58
59		if (ec == ELFCLASS32)
60			scn->s_shdr.s_shdr32.sh_size = (Elf32_Word) shnum;
61		else
62			scn->s_shdr.s_shdr64.sh_size = shnum;
63
64		(void) elf_flagshdr(scn, ELF_C_SET, ELF_F_DIRTY);
65
66		shnum = 0;
67	}
68
69	if (ec == ELFCLASS32)
70		((Elf32_Ehdr *) eh)->e_shnum = shnum & 0xFFFFU;
71	else
72		((Elf64_Ehdr *) eh)->e_shnum = shnum & 0xFFFFU;
73
74
75	return (1);
76}
77
78int
79_libelf_setshstrndx(Elf *e, void *eh, int ec, size_t shstrndx)
80{
81	Elf_Scn *scn;
82
83	if (shstrndx >= SHN_LORESERVE) {
84		if ((scn = _libelf_getscn0(e)) == NULL)
85			return (0);
86
87		assert(scn->s_ndx == SHN_UNDEF);
88
89		if (ec == ELFCLASS32)
90			scn->s_shdr.s_shdr32.sh_link = (Elf32_Word) shstrndx;
91		else
92			scn->s_shdr.s_shdr64.sh_link = (Elf64_Word) shstrndx;
93
94		(void) elf_flagshdr(scn, ELF_C_SET, ELF_F_DIRTY);
95
96		shstrndx = SHN_XINDEX;
97	}
98
99	if (ec == ELFCLASS32)
100		((Elf32_Ehdr *) eh)->e_shstrndx = shstrndx & 0xFFFFU;
101	else
102		((Elf64_Ehdr *) eh)->e_shstrndx = shstrndx & 0xFFFFU;
103
104	return (1);
105}
106
107int
108_libelf_setphnum(Elf *e, void *eh, int ec, size_t phnum)
109{
110	Elf_Scn *scn;
111
112	if (phnum >= PN_XNUM) {
113		if ((scn = _libelf_getscn0(e)) == NULL)
114			return (0);
115
116		assert(scn->s_ndx == SHN_UNDEF);
117
118		if (ec == ELFCLASS32)
119			scn->s_shdr.s_shdr32.sh_info = (Elf32_Word) phnum;
120		else
121			scn->s_shdr.s_shdr64.sh_info = (Elf64_Word) phnum;
122
123		(void) elf_flagshdr(scn, ELF_C_SET, ELF_F_DIRTY);
124
125		phnum = PN_XNUM;
126	}
127
128	if (ec == ELFCLASS32)
129		((Elf32_Ehdr *) eh)->e_phnum = phnum & 0xFFFFU;
130	else
131		((Elf64_Ehdr *) eh)->e_phnum = phnum & 0xFFFFU;
132
133	return (1);
134}
135