2 * IPv6 Hop Limit Target module
3 * Maciej Soltysiak <solt@dns.toxicfilms.tv>
4 * Based on HW's ttl target
5 * This program is distributed under the terms of GNU GPL
12 #include <ip6tables.h>
14 #include <linux/netfilter_ipv6/ip6_tables.h>
15 #include <linux/netfilter_ipv6/ip6t_HL.h>
17 #define IP6T_HL_USED 1
19 static void init(struct ip6t_entry_target
*t
, unsigned int *nfcache
)
23 static void help(void)
26 "HL target v%s options\n"
27 " --hl-set value Set HL to <value 0-255>\n"
28 " --hl-dec value Decrement HL by <value 1-255>\n"
29 " --hl-inc value Increment HL by <value 1-255>\n"
33 static int parse(int c
, char **argv
, int invert
, unsigned int *flags
,
34 const struct ip6t_entry
*entry
,
35 struct ip6t_entry_target
**target
)
37 struct ip6t_HL_info
*info
= (struct ip6t_HL_info
*) (*target
)->data
;
40 if (*flags
& IP6T_HL_USED
) {
41 exit_error(PARAMETER_PROBLEM
,
42 "Can't specify HL option twice");
46 exit_error(PARAMETER_PROBLEM
,
47 "HL: You must specify a value");
49 if (check_inverse(optarg
, &invert
, NULL
, 0))
50 exit_error(PARAMETER_PROBLEM
,
51 "HL: unexpected `!'");
53 if (string_to_number(optarg
, 0, 255, &value
) == -1)
54 exit_error(PARAMETER_PROBLEM
,
55 "HL: Expected value between 0 and 255");
60 info
->mode
= IP6T_HL_SET
;
65 exit_error(PARAMETER_PROBLEM
,
66 "HL: decreasing by 0?");
69 info
->mode
= IP6T_HL_DEC
;
74 exit_error(PARAMETER_PROBLEM
,
75 "HL: increasing by 0?");
78 info
->mode
= IP6T_HL_INC
;
86 info
->hop_limit
= value
;
87 *flags
|= IP6T_HL_USED
;
92 static void final_check(unsigned int flags
)
94 if (!(flags
& IP6T_HL_USED
))
95 exit_error(PARAMETER_PROBLEM
,
96 "HL: You must specify an action");
99 static void save(const struct ip6t_ip6
*ip
,
100 const struct ip6t_entry_target
*target
)
102 const struct ip6t_HL_info
*info
=
103 (struct ip6t_HL_info
*) target
->data
;
105 switch (info
->mode
) {
117 printf("%u ", info
->hop_limit
);
120 static void print(const struct ip6t_ip6
*ip
,
121 const struct ip6t_entry_target
*target
, int numeric
)
123 const struct ip6t_HL_info
*info
=
124 (struct ip6t_HL_info
*) target
->data
;
127 switch (info
->mode
) {
132 printf("decrement by ");
135 printf("increment by ");
138 printf("%u ", info
->hop_limit
);
141 static struct option opts
[] = {
142 { "hl-set", 1, 0, '1' },
143 { "hl-dec", 1, 0, '2' },
144 { "hl-inc", 1, 0, '3' },
149 struct ip6tables_target HL
= { NULL
,
151 .version
= IPTABLES_VERSION
,
152 .size
= IP6T_ALIGN(sizeof(struct ip6t_HL_info
)),
153 .userspacesize
= IP6T_ALIGN(sizeof(struct ip6t_HL_info
)),
157 .final_check
= &final_check
,
165 register_target6(&HL
);