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
39 void *
_libelf_getphdr(Elf * e,int ec)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
112 void *
_libelf_newphdr(Elf * e,int ec,size_t count)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