1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
|
/* libxelf - elf_file access routines
*
* by scut / teso
*/
#include <elf.h>
#include <stdio.h>
#include <stdlib.h>
#include <common.h>
#include <elf_file.h>
#include <elf_verify.h>
#include <elf_util.h>
elf_file *
elf_file_new (void)
{
elf_file * new = xcalloc (1, sizeof (elf_file));
return (new);
}
void
elf_file_destroy (elf_file *elf)
{
if (elf == NULL)
return;
if (elf->pathname != NULL)
free (elf->pathname);
if (elf->fp != NULL)
fclose (elf->fp);
if (elf->Phdr != NULL)
free (elf->Phdr);
if (elf->Shdr != NULL)
free (elf->Shdr);
if (elf->sh_str != NULL)
free (elf->sh_str);
free (elf);
return;
}
elf_file *
elf_file_load (char *pathname)
{
elf_file * new;
new = elf_file_new ();
new->fp = fopen (pathname, "rb");
if (new->fp == NULL) {
elf_error (NULL, "cannot open file: %s", pathname);
goto bail;
}
/* allocate and setup new ELF description structure
*/
new->pathname = xstrdup (pathname);
/* read in ELF header
*/
if (fread (&new->Ehdr, sizeof (new->Ehdr), 1, new->fp) != 1) {
elf_error (new, "failed to read ELF header");
goto bail;
}
if (elf_verify_header (new)) {
elf_error (new, "invalid ELF header");
goto bail;
}
/* read program header table
*/
new->Phdr = xcalloc (new->Ehdr.e_phnum, new->Ehdr.e_phentsize);
if (fseek (new->fp, new->Ehdr.e_phoff, SEEK_SET) != 0) {
elf_error (new, "failed to seek to ELF program header table at 0x%08x",
new->Ehdr.e_phoff);
goto bail;
}
if (fread (new->Phdr, new->Ehdr.e_phentsize, new->Ehdr.e_phnum,
new->fp) != new->Ehdr.e_phnum)
{
elf_error (new, "failed to read ELF program header table");
goto bail;
}
/* read section header table
*/
new->Shdr = xcalloc (new->Ehdr.e_shnum, new->Ehdr.e_shentsize);
if (fseek (new->fp, new->Ehdr.e_shoff, SEEK_SET) != 0) {
elf_error (new, "failed to seek to ELF section header table at 0x%08x",
new->Ehdr.e_shoff);
goto bail;
}
if (fread (new->Shdr, new->Ehdr.e_shentsize, new->Ehdr.e_shnum,
new->fp) != new->Ehdr.e_shnum)
{
elf_error (new, "failed to read ELF section header table");
goto bail;
}
/* read section header string table, if available
* XXX: this has to be done before any other section operations are
* done to set section->name correctly. -sc
*/
if (new->Ehdr.e_shstrndx == SHN_UNDEF)
return (new);
if (fseek (new->fp, new->Shdr[new->Ehdr.e_shstrndx].sh_offset,
SEEK_SET) != 0)
{
elf_error (new, "failed to seek to ELF string table section at 0x%08x",
new->Shdr[new->Ehdr.e_shstrndx].sh_offset);
goto bail;
}
#ifdef DEBUG
fprintf (stderr, "ELF section string table: %2d. at 0x%08lx\n",
new->Ehdr.e_shstrndx,
(unsigned long int) new->Shdr[new->Ehdr.e_shstrndx].sh_offset);
#endif
new->sh_str_len = new->Shdr[new->Ehdr.e_shstrndx].sh_size;
new->sh_str = xcalloc (1, new->sh_str_len);
if (fread (new->sh_str, 1, new->sh_str_len, new->fp) !=
new->sh_str_len)
{
elf_error (new, "failed to read ELF section string table");
goto bail;
}
return (new);
bail:
elf_file_destroy (new);
return (NULL);
}
|
