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 <sys/cdefs.h>
28
29 #include <assert.h>
30 #include <gelf.h>
31 #include <libelf.h>
32 #include <stdlib.h>
33
34 #include "_libelf.h"
35
36 ELFTC_VCSID("$Id$");
37
38 void *
_libelf_getphdr(Elf * e,int ec)39 _libelf_getphdr(Elf *e, int ec)
40 {
41 size_t phnum;
42 size_t fsz, msz;
43 uint64_t phoff;
44 Elf32_Ehdr *eh32;
45 Elf64_Ehdr *eh64;
46 void *ehdr, *phdr;
47 int (*xlator)(unsigned char *_d, size_t _dsz, unsigned char *_s,
48 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 phoff = (uint64_t) eh32->e_phoff;
74 } else {
75 eh64 = (Elf64_Ehdr *) ehdr;
76 phoff = (uint64_t) eh64->e_phoff;
77 }
78
79 fsz = gelf_fsize(e, ELF_T_PHDR, phnum, e->e_version);
80
81 assert(fsz > 0);
82
83 if ((uint64_t) e->e_rawsize < (phoff + fsz)) {
84 LIBELF_SET_ERROR(HEADER, 0);
85 return (NULL);
86 }
87
88 msz = _libelf_msize(ELF_T_PHDR, ec, EV_CURRENT);
89
90 assert(msz > 0);
91
92 if ((phdr = calloc(phnum, msz)) == NULL) {
93 LIBELF_SET_ERROR(RESOURCE, 0);
94 return (NULL);
95 }
96
97 if (ec == ELFCLASS32)
98 e->e_u.e_elf.e_phdr.e_phdr32 = phdr;
99 else
100 e->e_u.e_elf.e_phdr.e_phdr64 = phdr;
101
102
103 xlator = _libelf_get_translator(ELF_T_PHDR, ELF_TOMEMORY, ec);
104 (*xlator)(phdr, phnum * msz, e->e_rawfile + phoff, phnum,
105 e->e_byteorder != LIBELF_PRIVATE(byteorder));
106
107 return (phdr);
108 }
109
110 void *
_libelf_newphdr(Elf * e,int ec,size_t count)111 _libelf_newphdr(Elf *e, int ec, size_t count)
112 {
113 void *ehdr, *newphdr, *oldphdr;
114 size_t msz;
115
116 if (e == NULL) {
117 LIBELF_SET_ERROR(ARGUMENT, 0);
118 return (NULL);
119 }
120
121 if ((ehdr = _libelf_ehdr(e, ec, 0)) == NULL) {
122 LIBELF_SET_ERROR(SEQUENCE, 0);
123 return (NULL);
124 }
125
126 assert(e->e_class == ec);
127 assert(ec == ELFCLASS32 || ec == ELFCLASS64);
128 assert(e->e_version == EV_CURRENT);
129
130 msz = _libelf_msize(ELF_T_PHDR, ec, e->e_version);
131
132 assert(msz > 0);
133
134 newphdr = NULL;
135 if (count > 0 && (newphdr = calloc(count, msz)) == NULL) {
136 LIBELF_SET_ERROR(RESOURCE, 0);
137 return (NULL);
138 }
139
140 if (ec == ELFCLASS32) {
141 if ((oldphdr = (void *) e->e_u.e_elf.e_phdr.e_phdr32) != NULL)
142 free(oldphdr);
143 e->e_u.e_elf.e_phdr.e_phdr32 = (Elf32_Phdr *) newphdr;
144 } else {
145 if ((oldphdr = (void *) e->e_u.e_elf.e_phdr.e_phdr64) != NULL)
146 free(oldphdr);
147 e->e_u.e_elf.e_phdr.e_phdr64 = (Elf64_Phdr *) newphdr;
148 }
149
150 e->e_u.e_elf.e_nphdr = count;
151
152 elf_flagphdr(e, ELF_C_SET, ELF_F_DIRTY);
153
154 return (newphdr);
155 }
156