summaryrefslogtreecommitdiffstats
path: root/extensions/libip6t_REJECT.c
blob: 8c4cc7f348b36beea44c7d04968cdcefb55e02b0 (plain)
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
/* Shared library add-on to iptables to add customized REJECT support.
 *
 * (C) 2000 Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
 * 
 * ported to IPv6 by Harald Welte <laforge@gnumonks.org>
 *
 */
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <getopt.h>
#include <ip6tables.h>
#include <linux/netfilter_ipv6/ip6_tables.h>
#include <linux/netfilter_ipv6/ip6t_REJECT.h>

struct reject_names {
	const char *name;
	const char *alias;
	enum ip6t_reject_with with;
	const char *desc;
};

static const struct reject_names reject_table[] = {
	{"icmp6-no-route", "no-route",
		IP6T_ICMP6_NO_ROUTE, "ICMPv6 no route"},
	{"icmp6-adm-prohibited", "adm-prohibited",
		IP6T_ICMP6_ADM_PROHIBITED, "ICMPv6 administratively prohibited"},
#if 0
	{"icmp6-not-neighbor", "not-neighbor"},
		IP6T_ICMP6_NOT_NEIGHBOR, "ICMPv6 not a neighbor"},
#endif
	{"icmp6-addr-unreachable", "addr-unreach",
		IP6T_ICMP6_ADDR_UNREACH, "ICMPv6 address unreachable"},
	{"icmp6-port-unreachable", "port-unreach",
		IP6T_ICMP6_PORT_UNREACH, "ICMPv6 port unreachable"},
	{"tcp-reset", "tcp-reset",
		IP6T_TCP_RESET, "TCP RST packet"}
};

static void
print_reject_types()
{
	unsigned int i;

	printf("Valid reject types:\n");

	for (i = 0; i < sizeof(reject_table)/sizeof(struct reject_names); i++) {
		printf("    %-25s\t%s\n", reject_table[i].name, reject_table[i].desc);
		printf("    %-25s\talias\n", reject_table[i].alias);
	}
	printf("\n");
}

/* Saves the union ipt_targinfo in parsable form to stdout. */

/* Function which prints out usage message. */
static void
help(void)
{
	printf(
"REJECT options:\n"
"--reject-with type              drop input packet and send back\n"
"                                a reply packet according to type:\n");

	print_reject_types();
}

static struct option opts[] = {
	{ "reject-with", 1, 0, '1' },
	{ 0 }
};

/* Allocate and initialize the target. */
static void
init(struct ip6t_entry_target *t, unsigned int *nfcache)
{
	struct ip6t_reject_info *reject = (struct ip6t_reject_info *)t->data;

	/* default */
	reject->with = IP6T_ICMP6_PORT_UNREACH;

	/* Can't cache this */
	*nfcache |= NFC_UNKNOWN;
}

/* Function which parses command options; returns true if it
   ate an option */
static int
parse(int c, char **argv, int invert, unsigned int *flags,
      const struct ip6t_entry *entry,
      struct ip6t_entry_target **target)
{
	struct ip6t_reject_info *reject = 
		(struct ip6t_reject_info *)(*target)->data;
	unsigned int limit = sizeof(reject_table)/sizeof(struct reject_names);
	unsigned int i;

	switch(c) {
	case '1':
		if (check_inverse(optarg, &invert, NULL, 0))
			exit_error(PARAMETER_PROBLEM,
				   "Unexpected `!' after --reject-with");
		for (i = 0; i < limit; i++) {
			if ((strncasecmp(reject_table[i].name, optarg, strlen(optarg)) == 0)
			    || (strncasecmp(reject_table[i].alias, optarg, strlen(optarg)) == 0)) {
				reject->with = reject_table[i].with;
				return 1;
			}
		}
		exit_error(PARAMETER_PROBLEM, "unknown reject type `%s'",optarg);
	default:
		/* Fall through */
		break;
	}
	return 0;
}

/* Final check; nothing. */
static void final_check(unsigned int flags)
{
}

/* Prints out ipt_reject_info. */
static void
print(const struct ip6t_ip6 *ip,
      const struct ip6t_entry_target *target,
      int numeric)
{
	const struct ip6t_reject_info *reject
		= (const struct ip6t_reject_info *)target->data;
	unsigned int i;

	for (i = 0; i < sizeof(reject_table)/sizeof(struct reject_names); i++) {
		if (reject_table[i].with == reject->with)
			break;
	}
	printf("reject-with %s ", reject_table[i].name);
}

/* Saves ipt_reject in parsable form to stdout. */
static void save(const struct ip6t_ip6 *ip, 
		 const struct ip6t_entry_target *target)
{
	const struct ip6t_reject_info *reject
		= (const struct ip6t_reject_info *)target->data;
	unsigned int i;

	for (i = 0; i < sizeof(reject_table)/sizeof(struct reject_names); i++)
		if (reject_table[i].with == reject->with)
			break;

	printf("--reject-with %s ", reject_table[i].name);
}

struct ip6tables_target reject
= { NULL,
    "REJECT",
    IPTABLES_VERSION,
    IP6T_ALIGN(sizeof(struct ip6t_reject_info)),
    IP6T_ALIGN(sizeof(struct ip6t_reject_info)),
    &help,
    &init,
    &parse,
    &final_check,
    &print,
    &save,
    opts
};

void _init(void)
{
	register_target6(&reject);
}