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
163
164
|
/*
* netsniff-ng - the packet sniffing beast
* Copyright 2011 Daniel Borkmann <dborkma@tik.ee.ethz.ch>,
* Swiss federal institute of technology (ETH Zurich)
* Subject to the GPL, version 2.
*/
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <getopt.h>
#include <ctype.h>
#include <unistd.h>
#include <sys/fsuid.h>
#include "xmalloc.h"
#include "die.h"
#include "bpf.h"
#include "config.h"
#include "str.h"
static const char *short_options = "vhi:Vdbf:pD:";
static const struct option long_options[] = {
{"input", required_argument, NULL, 'i'},
{"format", required_argument, NULL, 'f'},
{"cpp", no_argument, NULL, 'p'},
{"define", required_argument, NULL, 'D'},
{"verbose", no_argument, NULL, 'V'},
{"bypass", no_argument, NULL, 'b'},
{"dump", no_argument, NULL, 'd'},
{"version", no_argument, NULL, 'v'},
{"help", no_argument, NULL, 'h'},
{NULL, 0, NULL, 0}
};
static const char *copyright =
"Please report bugs at https://github.com/netsniff-ng/netsniff-ng/issues\n"
"Copyright (C) 2011-2013 Daniel Borkmann <dborkma@tik.ee.ethz.ch>,\n"
"Swiss federal institute of technology (ETH Zurich)\n"
"License: GNU GPL version 2.0\n"
"This is free software: you are free to change and redistribute it.\n"
"There is NO WARRANTY, to the extent permitted by law.";
extern int compile_filter(char *file, bool verbose, int bypass, int format,
bool invoke_cpp, char **cpp_argv);
static void __noreturn help(void)
{
printf("bpfc %s, a tiny BPF compiler\n", VERSION_STRING);
puts("http://www.netsniff-ng.org\n\n"
"Usage: bpfc [options] || bpfc <program>\n"
"Options:\n"
" -i|--input <program/-> Berkeley Packet Filter file/stdin\n"
" -p|--cpp Run bpf program through C preprocessor\n"
" -D|--define Add macro/define for C preprocessor\n"
" -f|--format <format> Output format: C|netsniff-ng|xt_bpf|tcpdump\n"
" -b|--bypass Bypass filter validation (e.g. for bug testing)\n"
" -V|--verbose Be more verbose\n"
" -d|--dump Dump supported instruction table\n"
" -v|--version Print version and exit\n"
" -h|--help Print this help and exit\n\n"
"Examples:\n"
" bpfc fubar\n"
" bpfc fubar > foo (bpfc -f C -i fubar > foo) --> netsniff-ng -f foo ...\n"
" bpfc -f tcpdump -i fubar > foo --> tcpdump -ddd like ...\n"
" bpfc -f xt_bpf -b -p -i fubar\n"
" iptables -A INPUT -m bpf --bytecode \"`./bpfc -f xt_bpf -i fubar`\" -j LOG\n"
" bpfc - (read from stdin)\n"
"Note:\n"
" Generation of seccomp-BPF filters are fully supported as well.\n");
puts(copyright);
die();
}
static void __noreturn version(void)
{
printf("bpfc %s, Git id: %s\n", VERSION_LONG, GITVERSION);
puts("a tiny BPF compiler\n"
"http://www.netsniff-ng.org\n");
puts(copyright);
die();
}
int main(int argc, char **argv)
{
int ret, c, bypass = 0, format = 0;
bool verbose = false, invoke_cpp = false;
char **cpp_argv = NULL;
size_t cpp_argc = 0;
char *file = NULL;
setfsuid(getuid());
setfsgid(getgid());
if (argc == 1)
help();
while ((c = getopt_long(argc, argv, short_options, long_options,
NULL)) != EOF) {
switch (c) {
case 'h':
help();
break;
case 'v':
version();
break;
case 'V':
verbose = true;
break;
case 'p':
invoke_cpp = true;
break;
case 'D':
cpp_argv = argv_insert(cpp_argv, &cpp_argc, "-D");
cpp_argv = argv_insert(cpp_argv, &cpp_argc, optarg);
break;
case 'f':
if (!strncmp(optarg, "C", 1) ||
!strncmp(optarg, "netsniff-ng", 11))
format = 0;
else if (!strncmp(optarg, "tcpdump", 7))
format = 2;
else if (!strncmp(optarg, "xt_bpf", 6) ||
!strncmp(optarg, "tc", 2))
format = 1;
else
help();
break;
case 'b':
bypass = 1;
break;
case 'd':
bpf_dump_op_table();
die();
case 'i':
file = xstrdup(optarg);
break;
case '?':
switch (optopt) {
case 'i':
case 'f':
panic("Option -%c requires an argument!\n",
optopt);
default:
if (isprint(optopt))
printf("Unknown option character `0x%X\'!\n", optopt);
die();
}
default:
break;
}
}
if (argc == 2)
file = xstrdup(argv[1]);
if (!file)
panic("No Berkeley Packet Filter program specified!\n");
ret = compile_filter(file, verbose, bypass, format, invoke_cpp, cpp_argv);
argv_free(cpp_argv);
xfree(file);
return ret;
}
|
