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
|
/*
* IPv6 Hop Limit Target module
* Maciej Soltysiak <solt@dns.toxicfilms.tv>
* Based on HW's ttl target
* This program is distributed under the terms of GNU GPL
*/
#include <getopt.h>
#include <stdbool.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <xtables.h>
#include <linux/netfilter_ipv6/ip6t_HL.h>
#define IP6T_HL_USED 1
static void HL_help(void)
{
printf(
"HL target options\n"
" --hl-set value Set HL to <value 0-255>\n"
" --hl-dec value Decrement HL by <value 1-255>\n"
" --hl-inc value Increment HL by <value 1-255>\n");
}
static int HL_parse(int c, char **argv, int invert, unsigned int *flags,
const void *entry, struct xt_entry_target **target)
{
struct ip6t_HL_info *info = (struct ip6t_HL_info *) (*target)->data;
unsigned int value;
if (*flags & IP6T_HL_USED) {
xtables_error(PARAMETER_PROBLEM,
"Can't specify HL option twice");
}
if (!optarg)
xtables_error(PARAMETER_PROBLEM,
"HL: You must specify a value");
if (xtables_check_inverse(optarg, &invert, NULL, 0, argv))
xtables_error(PARAMETER_PROBLEM,
"HL: unexpected `!'");
if (!xtables_strtoui(optarg, NULL, &value, 0, UINT8_MAX))
xtables_error(PARAMETER_PROBLEM,
"HL: Expected value between 0 and 255");
switch (c) {
case '1':
info->mode = IP6T_HL_SET;
break;
case '2':
if (value == 0) {
xtables_error(PARAMETER_PROBLEM,
"HL: decreasing by 0?");
}
info->mode = IP6T_HL_DEC;
break;
case '3':
if (value == 0) {
xtables_error(PARAMETER_PROBLEM,
"HL: increasing by 0?");
}
info->mode = IP6T_HL_INC;
break;
}
info->hop_limit = value;
*flags |= IP6T_HL_USED;
return 1;
}
static void HL_check(unsigned int flags)
{
if (!(flags & IP6T_HL_USED))
xtables_error(PARAMETER_PROBLEM,
"HL: You must specify an action");
}
static void HL_save(const void *ip, const struct xt_entry_target *target)
{
const struct ip6t_HL_info *info =
(struct ip6t_HL_info *) target->data;
switch (info->mode) {
case IP6T_HL_SET:
printf(" --hl-set");
break;
case IP6T_HL_DEC:
printf(" --hl-dec");
break;
case IP6T_HL_INC:
printf(" --hl-inc");
break;
}
printf(" %u", info->hop_limit);
}
static void HL_print(const void *ip, const struct xt_entry_target *target,
int numeric)
{
const struct ip6t_HL_info *info =
(struct ip6t_HL_info *) target->data;
printf(" HL ");
switch (info->mode) {
case IP6T_HL_SET:
printf("set to");
break;
case IP6T_HL_DEC:
printf("decrement by");
break;
case IP6T_HL_INC:
printf("increment by");
break;
}
printf(" %u", info->hop_limit);
}
static const struct option HL_opts[] = {
{.name = "hl-set", .has_arg = true, .val = '1'},
{.name = "hl-dec", .has_arg = true, .val = '2'},
{.name = "hl-inc", .has_arg = true, .val = '3'},
XT_GETOPT_TABLEEND,
};
static struct xtables_target hl_tg6_reg = {
.name = "HL",
.version = XTABLES_VERSION,
.family = NFPROTO_IPV6,
.size = XT_ALIGN(sizeof(struct ip6t_HL_info)),
.userspacesize = XT_ALIGN(sizeof(struct ip6t_HL_info)),
.help = HL_help,
.parse = HL_parse,
.final_check = HL_check,
.print = HL_print,
.save = HL_save,
.extra_opts = HL_opts,
};
void _init(void)
{
xtables_register_target(&hl_tg6_reg);
}
|
