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
151
152
153
154
155
156
157
158
159
160
161
162
|
/*
* Based on:
*
* Minimal BPF JIT image disassembler
*
* Disassembles BPF JIT compiler emitted opcodes back to asm insn's for
* debugging or verification purposes.
*
* Copyright 2013 Daniel Borkmann <daniel@iogearbox.net>
* Licensed under the GNU General Public License, version 2.0 (GPLv2)
*/
#include <stdarg.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include <unistd.h>
#include <string.h>
#include <bfd.h>
#include <dis-asm.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <limits.h>
#include "json_writer.h"
#include "main.h"
static void get_exec_path(char *tpath, size_t size)
{
ssize_t len;
char *path;
snprintf(tpath, size, "/proc/%d/exe", (int) getpid());
tpath[size - 1] = 0;
path = strdup(tpath);
assert(path);
len = readlink(path, tpath, size - 1);
assert(len > 0);
tpath[len] = 0;
free(path);
}
static int oper_count;
static int fprintf_json(void *out, const char *fmt, ...)
{
va_list ap;
char *s;
va_start(ap, fmt);
if (!oper_count) {
int i;
s = va_arg(ap, char *);
/* Strip trailing spaces */
i = strlen(s) - 1;
while (s[i] == ' ')
s[i--] = '\0';
jsonw_string_field(json_wtr, "operation", s);
jsonw_name(json_wtr, "operands");
jsonw_start_array(json_wtr);
oper_count++;
} else if (!strcmp(fmt, ",")) {
/* Skip */
} else {
s = va_arg(ap, char *);
jsonw_string(json_wtr, s);
oper_count++;
}
va_end(ap);
return 0;
}
void disasm_print_insn(unsigned char *image, ssize_t len, int opcodes)
{
disassembler_ftype disassemble;
struct disassemble_info info;
int count, i, pc = 0;
char tpath[PATH_MAX];
bfd *bfdf;
if (!len)
return;
memset(tpath, 0, sizeof(tpath));
get_exec_path(tpath, sizeof(tpath));
bfdf = bfd_openr(tpath, NULL);
assert(bfdf);
assert(bfd_check_format(bfdf, bfd_object));
if (json_output)
init_disassemble_info(&info, stdout,
(fprintf_ftype) fprintf_json);
else
init_disassemble_info(&info, stdout,
(fprintf_ftype) fprintf);
info.arch = bfd_get_arch(bfdf);
info.mach = bfd_get_mach(bfdf);
info.buffer = image;
info.buffer_length = len;
disassemble_init_for_target(&info);
disassemble = disassembler(bfdf);
assert(disassemble);
if (json_output)
jsonw_start_array(json_wtr);
do {
if (json_output) {
jsonw_start_object(json_wtr);
oper_count = 0;
jsonw_name(json_wtr, "pc");
jsonw_printf(json_wtr, "\"0x%x\"", pc);
} else {
printf("%4x:\t", pc);
}
count = disassemble(pc, &info);
if (json_output) {
/* Operand array, was started in fprintf_json. Before
* that, make sure we have a _null_ value if no operand
* other than operation code was present.
*/
if (oper_count == 1)
jsonw_null(json_wtr);
jsonw_end_array(json_wtr);
}
if (opcodes) {
if (json_output) {
jsonw_name(json_wtr, "opcodes");
jsonw_start_array(json_wtr);
for (i = 0; i < count; ++i)
jsonw_printf(json_wtr, "\"0x%02hhx\"",
(uint8_t)image[pc + i]);
jsonw_end_array(json_wtr);
} else {
printf("\n\t");
for (i = 0; i < count; ++i)
printf("%02x ",
(uint8_t)image[pc + i]);
}
}
if (json_output)
jsonw_end_object(json_wtr);
else
printf("\n");
pc += count;
} while (count > 0 && pc < len);
if (json_output)
jsonw_end_array(json_wtr);
bfd_close(bfdf);
}
|
