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 <gelf.h>
29 #include <libelf.h>
30 #include <stdlib.h>
31
32 #include "_libelf.h"
33
34 ELFTC_VCSID("$Id: libelf_phdr.c 3174 2015-03-27 17:13:41Z emaste $");
35
36 void *
_libelf_getphdr(Elf * e,int ec)37 _libelf_getphdr(Elf *e, int ec)
38 {
39 size_t phnum;
40 size_t fsz, msz;
41 uint64_t phoff;
42 Elf32_Ehdr *eh32;
43 Elf64_Ehdr *eh64;
44 void *ehdr, *phdr;
45 int (*xlator)(unsigned char *_d, size_t _dsz, unsigned char *_s,
46 size_t _c, int _swap);
47
48 assert(ec == ELFCLASS32 || ec == ELFCLASS64);
49
50 if (e == NULL) {
51 LIBELF_SET_ERROR(ARGUMENT, 0);
52 return (NULL);
53 }
54
55 if ((phdr = (ec == ELFCLASS32 ?
56 (void *) e->e_u.e_elf.e_phdr.e_phdr32 :
57 (void *) e->e_u.e_elf.e_phdr.e_phdr64)) != NULL)
58 return (phdr);
59
60 /*
61 * Check the PHDR related fields in the EHDR for sanity.
62 */
63
64 if ((ehdr = _libelf_ehdr(e, ec, 0)) == NULL)
65 return (NULL);
66
67 phnum = e->e_u.e_elf.e_nphdr;
68
69 if (ec == ELFCLASS32) {
70 eh32 = (Elf32_Ehdr *) ehdr;
71 phoff = (uint64_t) eh32->e_phoff;
72 } else {
73 eh64 = (Elf64_Ehdr *) ehdr;
74 phoff = (uint64_t) eh64->e_phoff;
75 }
76
77 fsz = gelf_fsize(e, ELF_T_PHDR, phnum, e->e_version);
78
79 assert(fsz > 0);
80
81 if ((uint64_t) e->e_rawsize < (phoff + fsz)) {
82 LIBELF_SET_ERROR(HEADER, 0);
83 return (NULL);
84 }
85
86 msz = _libelf_msize(ELF_T_PHDR, ec, EV_CURRENT);
87
88 assert(msz > 0);
89
90 if ((phdr = calloc(phnum, msz)) == NULL) {
91 LIBELF_SET_ERROR(RESOURCE, 0);
92 return (NULL);
93 }
94
95 if (ec == ELFCLASS32)
96 e->e_u.e_elf.e_phdr.e_phdr32 = phdr;
97 else
98 e->e_u.e_elf.e_phdr.e_phdr64 = phdr;
99
100
101 xlator = _libelf_get_translator(ELF_T_PHDR, ELF_TOMEMORY, ec);
102 (*xlator)(phdr, phnum * msz, e->e_rawfile + phoff, phnum,
103 e->e_byteorder != LIBELF_PRIVATE(byteorder));
104
105 return (phdr);
106 }
107
108 void *
_libelf_newphdr(Elf * e,int ec,size_t count)109 _libelf_newphdr(Elf *e, int ec, size_t count)
110 {
111 void *ehdr, *newphdr, *oldphdr;
112 size_t msz;
113
114 if (e == NULL) {
115 LIBELF_SET_ERROR(ARGUMENT, 0);
116 return (NULL);
117 }
118
119 if ((ehdr = _libelf_ehdr(e, ec, 0)) == NULL) {
120 LIBELF_SET_ERROR(SEQUENCE, 0);
121 return (NULL);
122 }
123
124 assert(e->e_class == ec);
125 assert(ec == ELFCLASS32 || ec == ELFCLASS64);
126 assert(e->e_version == EV_CURRENT);
127
128 msz = _libelf_msize(ELF_T_PHDR, ec, e->e_version);
129
130 assert(msz > 0);
131
132 newphdr = NULL;
133 if (count > 0 && (newphdr = calloc(count, msz)) == NULL) {
134 LIBELF_SET_ERROR(RESOURCE, 0);
135 return (NULL);
136 }
137
138 if (ec == ELFCLASS32) {
139 if ((oldphdr = (void *) e->e_u.e_elf.e_phdr.e_phdr32) != NULL)
140 free(oldphdr);
141 e->e_u.e_elf.e_phdr.e_phdr32 = (Elf32_Phdr *) newphdr;
142 } else {
143 if ((oldphdr = (void *) e->e_u.e_elf.e_phdr.e_phdr64) != NULL)
144 free(oldphdr);
145 e->e_u.e_elf.e_phdr.e_phdr64 = (Elf64_Phdr *) newphdr;
146 }
147
148 e->e_u.e_elf.e_nphdr = count;
149
150 elf_flagphdr(e, ELF_C_SET, ELF_F_DIRTY);
151
152 return (newphdr);
153 }
154