xref: /aosp_15_r20/external/iptables/extensions/libip6t_HL.c (revision a71a954618bbadd4a345637e5edcf36eec826889)
1*a71a9546SAutomerger Merge Worker /*
2*a71a9546SAutomerger Merge Worker  * IPv6 Hop Limit Target module
3*a71a9546SAutomerger Merge Worker  * Maciej Soltysiak <[email protected]>
4*a71a9546SAutomerger Merge Worker  * Based on HW's ttl target
5*a71a9546SAutomerger Merge Worker  * This program is distributed under the terms of GNU GPL
6*a71a9546SAutomerger Merge Worker  */
7*a71a9546SAutomerger Merge Worker #include <stdio.h>
8*a71a9546SAutomerger Merge Worker #include <xtables.h>
9*a71a9546SAutomerger Merge Worker #include <linux/netfilter_ipv6/ip6t_HL.h>
10*a71a9546SAutomerger Merge Worker 
11*a71a9546SAutomerger Merge Worker enum {
12*a71a9546SAutomerger Merge Worker 	O_HL_SET = 0,
13*a71a9546SAutomerger Merge Worker 	O_HL_INC,
14*a71a9546SAutomerger Merge Worker 	O_HL_DEC,
15*a71a9546SAutomerger Merge Worker 	F_HL_SET = 1 << O_HL_SET,
16*a71a9546SAutomerger Merge Worker 	F_HL_INC = 1 << O_HL_INC,
17*a71a9546SAutomerger Merge Worker 	F_HL_DEC = 1 << O_HL_DEC,
18*a71a9546SAutomerger Merge Worker 	F_ANY    = F_HL_SET | F_HL_INC | F_HL_DEC,
19*a71a9546SAutomerger Merge Worker };
20*a71a9546SAutomerger Merge Worker 
21*a71a9546SAutomerger Merge Worker #define s struct ip6t_HL_info
22*a71a9546SAutomerger Merge Worker static const struct xt_option_entry HL_opts[] = {
23*a71a9546SAutomerger Merge Worker 	{.name = "hl-set", .type = XTTYPE_UINT8, .id = O_HL_SET,
24*a71a9546SAutomerger Merge Worker 	 .excl = F_ANY, .flags = XTOPT_PUT, XTOPT_POINTER(s, hop_limit)},
25*a71a9546SAutomerger Merge Worker 	{.name = "hl-dec", .type = XTTYPE_UINT8, .id = O_HL_DEC,
26*a71a9546SAutomerger Merge Worker 	 .excl = F_ANY, .flags = XTOPT_PUT, XTOPT_POINTER(s, hop_limit),
27*a71a9546SAutomerger Merge Worker 	 .min = 1},
28*a71a9546SAutomerger Merge Worker 	{.name = "hl-inc", .type = XTTYPE_UINT8, .id = O_HL_INC,
29*a71a9546SAutomerger Merge Worker 	 .excl = F_ANY, .flags = XTOPT_PUT, XTOPT_POINTER(s, hop_limit),
30*a71a9546SAutomerger Merge Worker 	 .min = 1},
31*a71a9546SAutomerger Merge Worker 	XTOPT_TABLEEND,
32*a71a9546SAutomerger Merge Worker };
33*a71a9546SAutomerger Merge Worker #undef s
34*a71a9546SAutomerger Merge Worker 
HL_help(void)35*a71a9546SAutomerger Merge Worker static void HL_help(void)
36*a71a9546SAutomerger Merge Worker {
37*a71a9546SAutomerger Merge Worker 	printf(
38*a71a9546SAutomerger Merge Worker "HL target options\n"
39*a71a9546SAutomerger Merge Worker "  --hl-set value		Set HL to <value 0-255>\n"
40*a71a9546SAutomerger Merge Worker "  --hl-dec value		Decrement HL by <value 1-255>\n"
41*a71a9546SAutomerger Merge Worker "  --hl-inc value		Increment HL by <value 1-255>\n");
42*a71a9546SAutomerger Merge Worker }
43*a71a9546SAutomerger Merge Worker 
HL_parse(struct xt_option_call * cb)44*a71a9546SAutomerger Merge Worker static void HL_parse(struct xt_option_call *cb)
45*a71a9546SAutomerger Merge Worker {
46*a71a9546SAutomerger Merge Worker 	struct ip6t_HL_info *info = cb->data;
47*a71a9546SAutomerger Merge Worker 
48*a71a9546SAutomerger Merge Worker 	xtables_option_parse(cb);
49*a71a9546SAutomerger Merge Worker 	switch (cb->entry->id) {
50*a71a9546SAutomerger Merge Worker 	case O_HL_SET:
51*a71a9546SAutomerger Merge Worker 		info->mode = IP6T_HL_SET;
52*a71a9546SAutomerger Merge Worker 		break;
53*a71a9546SAutomerger Merge Worker 	case O_HL_INC:
54*a71a9546SAutomerger Merge Worker 		info->mode = IP6T_HL_INC;
55*a71a9546SAutomerger Merge Worker 		break;
56*a71a9546SAutomerger Merge Worker 	case O_HL_DEC:
57*a71a9546SAutomerger Merge Worker 		info->mode = IP6T_HL_DEC;
58*a71a9546SAutomerger Merge Worker 		break;
59*a71a9546SAutomerger Merge Worker 	}
60*a71a9546SAutomerger Merge Worker }
61*a71a9546SAutomerger Merge Worker 
HL_check(struct xt_fcheck_call * cb)62*a71a9546SAutomerger Merge Worker static void HL_check(struct xt_fcheck_call *cb)
63*a71a9546SAutomerger Merge Worker {
64*a71a9546SAutomerger Merge Worker 	if (!(cb->xflags & F_ANY))
65*a71a9546SAutomerger Merge Worker 		xtables_error(PARAMETER_PROBLEM,
66*a71a9546SAutomerger Merge Worker 				"HL: You must specify an action");
67*a71a9546SAutomerger Merge Worker }
68*a71a9546SAutomerger Merge Worker 
HL_save(const void * ip,const struct xt_entry_target * target)69*a71a9546SAutomerger Merge Worker static void HL_save(const void *ip, const struct xt_entry_target *target)
70*a71a9546SAutomerger Merge Worker {
71*a71a9546SAutomerger Merge Worker 	const struct ip6t_HL_info *info =
72*a71a9546SAutomerger Merge Worker 		(struct ip6t_HL_info *) target->data;
73*a71a9546SAutomerger Merge Worker 
74*a71a9546SAutomerger Merge Worker 	switch (info->mode) {
75*a71a9546SAutomerger Merge Worker 		case IP6T_HL_SET:
76*a71a9546SAutomerger Merge Worker 			printf(" --hl-set");
77*a71a9546SAutomerger Merge Worker 			break;
78*a71a9546SAutomerger Merge Worker 		case IP6T_HL_DEC:
79*a71a9546SAutomerger Merge Worker 			printf(" --hl-dec");
80*a71a9546SAutomerger Merge Worker 			break;
81*a71a9546SAutomerger Merge Worker 
82*a71a9546SAutomerger Merge Worker 		case IP6T_HL_INC:
83*a71a9546SAutomerger Merge Worker 			printf(" --hl-inc");
84*a71a9546SAutomerger Merge Worker 			break;
85*a71a9546SAutomerger Merge Worker 	}
86*a71a9546SAutomerger Merge Worker 	printf(" %u", info->hop_limit);
87*a71a9546SAutomerger Merge Worker }
88*a71a9546SAutomerger Merge Worker 
HL_print(const void * ip,const struct xt_entry_target * target,int numeric)89*a71a9546SAutomerger Merge Worker static void HL_print(const void *ip, const struct xt_entry_target *target,
90*a71a9546SAutomerger Merge Worker                      int numeric)
91*a71a9546SAutomerger Merge Worker {
92*a71a9546SAutomerger Merge Worker 	const struct ip6t_HL_info *info =
93*a71a9546SAutomerger Merge Worker 		(struct ip6t_HL_info *) target->data;
94*a71a9546SAutomerger Merge Worker 
95*a71a9546SAutomerger Merge Worker 	printf(" HL ");
96*a71a9546SAutomerger Merge Worker 	switch (info->mode) {
97*a71a9546SAutomerger Merge Worker 		case IP6T_HL_SET:
98*a71a9546SAutomerger Merge Worker 			printf("set to");
99*a71a9546SAutomerger Merge Worker 			break;
100*a71a9546SAutomerger Merge Worker 		case IP6T_HL_DEC:
101*a71a9546SAutomerger Merge Worker 			printf("decrement by");
102*a71a9546SAutomerger Merge Worker 			break;
103*a71a9546SAutomerger Merge Worker 		case IP6T_HL_INC:
104*a71a9546SAutomerger Merge Worker 			printf("increment by");
105*a71a9546SAutomerger Merge Worker 			break;
106*a71a9546SAutomerger Merge Worker 	}
107*a71a9546SAutomerger Merge Worker 	printf(" %u", info->hop_limit);
108*a71a9546SAutomerger Merge Worker }
109*a71a9546SAutomerger Merge Worker 
110*a71a9546SAutomerger Merge Worker static struct xtables_target hl_tg6_reg = {
111*a71a9546SAutomerger Merge Worker 	.name 		= "HL",
112*a71a9546SAutomerger Merge Worker 	.version	= XTABLES_VERSION,
113*a71a9546SAutomerger Merge Worker 	.family		= NFPROTO_IPV6,
114*a71a9546SAutomerger Merge Worker 	.size		= XT_ALIGN(sizeof(struct ip6t_HL_info)),
115*a71a9546SAutomerger Merge Worker 	.userspacesize	= XT_ALIGN(sizeof(struct ip6t_HL_info)),
116*a71a9546SAutomerger Merge Worker 	.help		= HL_help,
117*a71a9546SAutomerger Merge Worker 	.print		= HL_print,
118*a71a9546SAutomerger Merge Worker 	.save		= HL_save,
119*a71a9546SAutomerger Merge Worker 	.x6_parse	= HL_parse,
120*a71a9546SAutomerger Merge Worker 	.x6_fcheck	= HL_check,
121*a71a9546SAutomerger Merge Worker 	.x6_options	= HL_opts,
122*a71a9546SAutomerger Merge Worker };
123*a71a9546SAutomerger Merge Worker 
_init(void)124*a71a9546SAutomerger Merge Worker void _init(void)
125*a71a9546SAutomerger Merge Worker {
126*a71a9546SAutomerger Merge Worker 	xtables_register_target(&hl_tg6_reg);
127*a71a9546SAutomerger Merge Worker }
128