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
|
/* Shared library add-on to iptables for ECN matching
*
* (C) 2002 by Harald Welte <laforge@gnumonks.org>
*
* This program is distributed under the terms of GNU GPL v2, 1991
*
* libipt_ecn.c borrowed heavily from libipt_dscp.c
*
*/
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <getopt.h>
#include <xtables.h>
#include <linux/netfilter_ipv4/ipt_ecn.h>
static void ecn_help(void)
{
printf(
"ECN match options\n"
"[!] --ecn-tcp-cwr Match CWR bit of TCP header\n"
"[!] --ecn-tcp-ece Match ECE bit of TCP header\n"
"[!] --ecn-ip-ect [0..3] Match ECN codepoint in IPv4 header\n");
}
static const struct option ecn_opts[] = {
{ .name = "ecn-tcp-cwr", .has_arg = 0, .val = 'F' },
{ .name = "ecn-tcp-ece", .has_arg = 0, .val = 'G' },
{ .name = "ecn-ip-ect", .has_arg = 1, .val = 'H' },
{ .name = NULL }
};
static int ecn_parse(int c, char **argv, int invert, unsigned int *flags,
const void *entry, struct xt_entry_match **match)
{
unsigned int result;
struct ipt_ecn_info *einfo
= (struct ipt_ecn_info *)(*match)->data;
switch (c) {
case 'F':
if (*flags & IPT_ECN_OP_MATCH_CWR)
xtables_error(PARAMETER_PROBLEM,
"ECN match: can only use parameter ONCE!");
xtables_check_inverse(optarg, &invert, &optind, 0, argv);
einfo->operation |= IPT_ECN_OP_MATCH_CWR;
if (invert)
einfo->invert |= IPT_ECN_OP_MATCH_CWR;
*flags |= IPT_ECN_OP_MATCH_CWR;
break;
case 'G':
if (*flags & IPT_ECN_OP_MATCH_ECE)
xtables_error(PARAMETER_PROBLEM,
"ECN match: can only use parameter ONCE!");
xtables_check_inverse(optarg, &invert, &optind, 0, argv);
einfo->operation |= IPT_ECN_OP_MATCH_ECE;
if (invert)
einfo->invert |= IPT_ECN_OP_MATCH_ECE;
*flags |= IPT_ECN_OP_MATCH_ECE;
break;
case 'H':
if (*flags & IPT_ECN_OP_MATCH_IP)
xtables_error(PARAMETER_PROBLEM,
"ECN match: can only use parameter ONCE!");
xtables_check_inverse(optarg, &invert, &optind, 0, argv);
if (invert)
einfo->invert |= IPT_ECN_OP_MATCH_IP;
*flags |= IPT_ECN_OP_MATCH_IP;
einfo->operation |= IPT_ECN_OP_MATCH_IP;
if (!xtables_strtoui(optarg, NULL, &result, 0, 3))
xtables_error(PARAMETER_PROBLEM,
"ECN match: Value out of range");
einfo->ip_ect = result;
break;
default:
return 0;
}
return 1;
}
static void ecn_check(unsigned int flags)
{
if (!flags)
xtables_error(PARAMETER_PROBLEM,
"ECN match: some option required");
}
static void ecn_print(const void *ip, const struct xt_entry_match *match,
int numeric)
{
const struct ipt_ecn_info *einfo =
(const struct ipt_ecn_info *)match->data;
printf("ECN match ");
if (einfo->operation & IPT_ECN_OP_MATCH_ECE) {
if (einfo->invert & IPT_ECN_OP_MATCH_ECE)
fputc('!', stdout);
printf("ECE ");
}
if (einfo->operation & IPT_ECN_OP_MATCH_CWR) {
if (einfo->invert & IPT_ECN_OP_MATCH_CWR)
fputc('!', stdout);
printf("CWR ");
}
if (einfo->operation & IPT_ECN_OP_MATCH_IP) {
if (einfo->invert & IPT_ECN_OP_MATCH_IP)
fputc('!', stdout);
printf("ECT=%d ", einfo->ip_ect);
}
}
static void ecn_save(const void *ip, const struct xt_entry_match *match)
{
const struct ipt_ecn_info *einfo =
(const struct ipt_ecn_info *)match->data;
if (einfo->operation & IPT_ECN_OP_MATCH_ECE) {
if (einfo->invert & IPT_ECN_OP_MATCH_ECE)
printf("! ");
printf("--ecn-tcp-ece ");
}
if (einfo->operation & IPT_ECN_OP_MATCH_CWR) {
if (einfo->invert & IPT_ECN_OP_MATCH_CWR)
printf("! ");
printf("--ecn-tcp-cwr ");
}
if (einfo->operation & IPT_ECN_OP_MATCH_IP) {
if (einfo->invert & IPT_ECN_OP_MATCH_IP)
printf("! ");
printf("--ecn-ip-ect %d", einfo->ip_ect);
}
}
static struct xtables_match ecn_mt_reg = {
.name = "ecn",
.version = XTABLES_VERSION,
.family = NFPROTO_IPV4,
.size = XT_ALIGN(sizeof(struct ipt_ecn_info)),
.userspacesize = XT_ALIGN(sizeof(struct ipt_ecn_info)),
.help = ecn_help,
.parse = ecn_parse,
.final_check = ecn_check,
.print = ecn_print,
.save = ecn_save,
.extra_opts = ecn_opts,
};
void _init(void)
{
xtables_register_match(&ecn_mt_reg);
}
|
