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
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
|
/* ebt_limit
*
* Authors:
* Tom Marshall <tommy@home.tig-grr.com>
*
* Mostly copied from iptables' limit match.
*
* September, 2003
*
* Translated to use libxtables for ebtables-compat in 2015 by
* Arturo Borrero Gonzalez <arturo@debian.org>
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <getopt.h>
#include <errno.h>
#include <xtables.h>
#include <linux/netfilter_bridge/ebt_limit.h>
#include "iptables/nft.h"
#include "iptables/nft-bridge.h"
#define EBT_LIMIT_AVG "3/hour"
#define EBT_LIMIT_BURST 5
#define FLAG_LIMIT 0x01
#define FLAG_LIMIT_BURST 0x02
#define ARG_LIMIT '1'
#define ARG_LIMIT_BURST '2'
static struct option brlimit_opts[] =
{
{ .name = "limit", .has_arg = true, .val = ARG_LIMIT },
{ .name = "limit-burst",.has_arg = true, .val = ARG_LIMIT_BURST },
XT_GETOPT_TABLEEND,
};
static void brlimit_print_help(void)
{
printf(
"limit options:\n"
"--limit avg : max average match rate: default "EBT_LIMIT_AVG"\n"
" [Packets per second unless followed by \n"
" /sec /minute /hour /day postfixes]\n"
"--limit-burst number : number to match in a burst, -1 < number < 10001,\n"
" default %u\n", EBT_LIMIT_BURST);
}
static int parse_rate(const char *rate, uint32_t *val)
{
const char *delim;
uint32_t r;
uint32_t mult = 1; /* Seconds by default. */
delim = strchr(rate, '/');
if (delim) {
if (strlen(delim+1) == 0)
return 0;
if (strncasecmp(delim+1, "second", strlen(delim+1)) == 0)
mult = 1;
else if (strncasecmp(delim+1, "minute", strlen(delim+1)) == 0)
mult = 60;
else if (strncasecmp(delim+1, "hour", strlen(delim+1)) == 0)
mult = 60*60;
else if (strncasecmp(delim+1, "day", strlen(delim+1)) == 0)
mult = 24*60*60;
else
return 0;
}
r = atoi(rate);
if (!r)
return 0;
/* This would get mapped to infinite (1/day is minimum they
can specify, so we're ok at that end). */
if (r / mult > EBT_LIMIT_SCALE)
return 0;
*val = EBT_LIMIT_SCALE * mult / r;
return 1;
}
static void brlimit_init(struct xt_entry_match *match)
{
struct ebt_limit_info *r = (struct ebt_limit_info *)match->data;
parse_rate(EBT_LIMIT_AVG, &r->avg);
r->burst = EBT_LIMIT_BURST;
}
static int brlimit_parse(int c, char **argv, int invert, unsigned int *flags,
const void *entry, struct xt_entry_match **match)
{
struct ebt_limit_info *r = (struct ebt_limit_info *)(*match)->data;
uintmax_t num;
switch (c) {
case ARG_LIMIT:
EBT_CHECK_OPTION(flags, FLAG_LIMIT);
if (invert)
xtables_error(PARAMETER_PROBLEM,
"Unexpected `!' after --limit");
if (!parse_rate(optarg, &r->avg))
xtables_error(PARAMETER_PROBLEM,
"bad rate `%s'", optarg);
break;
case ARG_LIMIT_BURST:
EBT_CHECK_OPTION(flags, FLAG_LIMIT_BURST);
if (invert)
xtables_error(PARAMETER_PROBLEM,
"Unexpected `!' after --limit-burst");
if (!xtables_strtoul(optarg, NULL, &num, 0, 10000))
xtables_error(PARAMETER_PROBLEM,
"bad --limit-burst `%s'", optarg);
r->burst = num;
break;
default:
return 0;
}
return 1;
}
struct rates
{
const char *name;
uint32_t mult;
};
static struct rates g_rates[] =
{
{ "day", EBT_LIMIT_SCALE*24*60*60 },
{ "hour", EBT_LIMIT_SCALE*60*60 },
{ "min", EBT_LIMIT_SCALE*60 },
{ "sec", EBT_LIMIT_SCALE }
};
static void print_rate(uint32_t period)
{
unsigned int i;
for (i = 1; i < sizeof(g_rates)/sizeof(struct rates); i++)
if (period > g_rates[i].mult ||
g_rates[i].mult/period < g_rates[i].mult%period)
break;
printf("%u/%s ", g_rates[i-1].mult / period, g_rates[i-1].name);
}
static void brlimit_print(const void *ip, const struct xt_entry_match *match,
int numeric)
{
struct ebt_limit_info *r = (struct ebt_limit_info *)match->data;
printf("--limit ");
print_rate(r->avg);
printf("--limit-burst %u ", r->burst);
}
static struct xtables_match brlimit_match = {
.name = "limit",
.revision = 0,
.version = XTABLES_VERSION,
.family = NFPROTO_BRIDGE,
.size = XT_ALIGN(sizeof(struct ebt_limit_info)),
.userspacesize = offsetof(struct ebt_limit_info, prev),
.init = brlimit_init,
.help = brlimit_print_help,
.parse = brlimit_parse,
.print = brlimit_print,
.extra_opts = brlimit_opts,
};
void _init(void)
{
xtables_register_match(&brlimit_match);
}
|
