1/*-
2 * Copyright (c) 2006 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 * $FreeBSD$
27 */
28
29#include <sys/cdefs.h>
30__FBSDID("$FreeBSD$");
31
32#include <assert.h>
33#include <gelf.h>
34#include <libelf.h>
35#include <stdlib.h>
36
37#include "_libelf.h"
38
39void *
40_libelf_getphdr(Elf *e, int ec)
41{
42	size_t phnum, phentsize;
43	size_t fsz, msz;
44	uint64_t phoff;
45	Elf32_Ehdr *eh32;
46	Elf64_Ehdr *eh64;
47	void *ehdr, *phdr;
48	int (*xlator)(char *_d, size_t _dsz, char *_s, size_t _c, int _swap);
49
50	assert(ec == ELFCLASS32 || ec == ELFCLASS64);
51
52	if (e == NULL) {
53		LIBELF_SET_ERROR(ARGUMENT, 0);
54		return (NULL);
55	}
56
57	if ((phdr = (ec == ELFCLASS32 ?
58		 (void *) e->e_u.e_elf.e_phdr.e_phdr32 :
59		 (void *) e->e_u.e_elf.e_phdr.e_phdr64)) != NULL)
60		return (phdr);
61
62	/*
63	 * Check the PHDR related fields in the EHDR for sanity.
64	 */
65
66	if ((ehdr = _libelf_ehdr(e, ec, 0)) == NULL)
67		return (NULL);
68
69	phnum = e->e_u.e_elf.e_nphdr;
70
71	if (ec == ELFCLASS32) {
72		eh32      = (Elf32_Ehdr *) ehdr;
73		phentsize = eh32->e_phentsize;
74		phoff     = (uint64_t) eh32->e_phoff;
75	} else {
76		eh64      = (Elf64_Ehdr *) ehdr;
77		phentsize = eh64->e_phentsize;
78		phoff     = (uint64_t) eh64->e_phoff;
79	}
80
81	fsz = gelf_fsize(e, ELF_T_PHDR, phnum, e->e_version);
82
83	assert(fsz > 0);
84
85	if ((uint64_t) e->e_rawsize < (phoff + fsz)) {
86		LIBELF_SET_ERROR(HEADER, 0);
87		return (NULL);
88	}
89
90	msz = _libelf_msize(ELF_T_PHDR, ec, EV_CURRENT);
91
92	assert(msz > 0);
93
94	if ((phdr = calloc(phnum, msz)) == NULL) {
95		LIBELF_SET_ERROR(RESOURCE, 0);
96		return (NULL);
97	}
98
99	if (ec == ELFCLASS32)
100		e->e_u.e_elf.e_phdr.e_phdr32 = phdr;
101	else
102		e->e_u.e_elf.e_phdr.e_phdr64 = phdr;
103
104
105	xlator = _libelf_get_translator(ELF_T_PHDR, ELF_TOMEMORY, ec);
106	(*xlator)(phdr, phnum * msz, e->e_rawfile + phoff, phnum,
107	    e->e_byteorder != LIBELF_PRIVATE(byteorder));
108
109	return (phdr);
110}
111
112void *
113_libelf_newphdr(Elf *e, int ec, size_t count)
114{
115	void *ehdr, *newphdr, *oldphdr;
116	size_t msz;
117
118	if (e == NULL) {
119		LIBELF_SET_ERROR(ARGUMENT, 0);
120		return (NULL);
121	}
122
123	if ((ehdr = _libelf_ehdr(e, ec, 0)) == NULL) {
124		LIBELF_SET_ERROR(SEQUENCE, 0);
125		return (NULL);
126	}
127
128	assert(e->e_class == ec);
129	assert(ec == ELFCLASS32 || ec == ELFCLASS64);
130	assert(e->e_version == EV_CURRENT);
131
132	msz = _libelf_msize(ELF_T_PHDR, ec, e->e_version);
133
134	assert(msz > 0);
135
136	newphdr = NULL;
137	if (count > 0 && (newphdr = calloc(count, msz)) == NULL) {
138		LIBELF_SET_ERROR(RESOURCE, 0);
139		return (NULL);
140	}
141
142	if (ec == ELFCLASS32) {
143		if ((oldphdr = (void *) e->e_u.e_elf.e_phdr.e_phdr32) != NULL)
144			free(oldphdr);
145		e->e_u.e_elf.e_phdr.e_phdr32 = (Elf32_Phdr *) newphdr;
146	} else {
147		if ((oldphdr = (void *) e->e_u.e_elf.e_phdr.e_phdr64) != NULL)
148			free(oldphdr);
149		e->e_u.e_elf.e_phdr.e_phdr64 = (Elf64_Phdr *) newphdr;
150	}
151
152	e->e_u.e_elf.e_nphdr = count;
153
154	elf_flagphdr(e, ELF_C_SET, ELF_F_DIRTY);
155
156	return (newphdr);
157}
158