summaryrefslogtreecommitdiffstats
path: root/extensions/libxt_pkttype.c
blob: 1ed3b445c32cbce9a6638aa364b74c2538b65867 (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
/* 
 * Shared library add-on to iptables to match 
 * packets by their type (BROADCAST, UNICAST, MULTICAST). 
 *
 * Michal Ludvig <michal@logix.cz>
 */
#include <stdio.h>
#include <string.h>
#include <xtables.h>
#include <linux/if_packet.h>
#include <linux/netfilter/xt_pkttype.h>

enum {
	O_PKTTYPE = 0,
};

struct pkttypes {
	const char *name;
	unsigned char pkttype;
	unsigned char printhelp;
	const char *help;
};

static const struct pkttypes supported_types[] = {
	{"unicast", PACKET_HOST, 1, "to us"},
	{"broadcast", PACKET_BROADCAST, 1, "to all"},
	{"multicast", PACKET_MULTICAST, 1, "to group"},
/*
	{"otherhost", PACKET_OTHERHOST, 1, "to someone else"},
	{"outgoing", PACKET_OUTGOING, 1, "outgoing of any type"},
*/
	/* aliases */
	{"bcast", PACKET_BROADCAST, 0, NULL},
	{"mcast", PACKET_MULTICAST, 0, NULL},
	{"host", PACKET_HOST, 0, NULL}
};

static void print_types(void)
{
	unsigned int	i;
	
	printf("Valid packet types:\n");
	for (i = 0; i < ARRAY_SIZE(supported_types); ++i)
		if(supported_types[i].printhelp == 1)
			printf("\t%-14s\t\t%s\n", supported_types[i].name, supported_types[i].help);
	printf("\n");
}

static void pkttype_help(void)
{
	printf(
"pkttype match options:\n"
"[!] --pkt-type packettype    match packet type\n");
	print_types();
}

static const struct xt_option_entry pkttype_opts[] = {
	{.name = "pkt-type", .id = O_PKTTYPE, .type = XTTYPE_STRING,
	 .flags = XTOPT_MAND | XTOPT_INVERT},
	XTOPT_TABLEEND,
};

static void parse_pkttype(const char *pkttype, struct xt_pkttype_info *info)
{
	unsigned int	i;
	
	for (i = 0; i < ARRAY_SIZE(supported_types); ++i)
		if(strcasecmp(pkttype, supported_types[i].name)==0)
		{
			info->pkttype=supported_types[i].pkttype;
			return;
		}
	
	xtables_error(PARAMETER_PROBLEM, "Bad packet type '%s'", pkttype);
}

static void pkttype_parse(struct xt_option_call *cb)
{
	struct xt_pkttype_info *info = cb->data;

	xtables_option_parse(cb);
	parse_pkttype(cb->arg, info);
	if (cb->invert)
		info->invert = 1;
}

static void print_pkttype(const struct xt_pkttype_info *info)
{
	unsigned int	i;
	
	for (i = 0; i < ARRAY_SIZE(supported_types); ++i)
		if(supported_types[i].pkttype==info->pkttype)
		{
			printf("%s", supported_types[i].name);
			return;
		}

	printf("%d", info->pkttype);	/* in case we didn't find an entry in named-packtes */
}

static void pkttype_print(const void *ip, const struct xt_entry_match *match,
                          int numeric)
{
	const struct xt_pkttype_info *info = (const void *)match->data;
	
	printf(" PKTTYPE %s= ", info->invert ? "!" : "");
	print_pkttype(info);
}

static void pkttype_save(const void *ip, const struct xt_entry_match *match)
{
	const struct xt_pkttype_info *info = (const void *)match->data;
	
	printf("%s --pkt-type ", info->invert ? " !" : "");
	print_pkttype(info);
}

static struct xtables_match pkttype_match = {
	.family		= NFPROTO_UNSPEC,
	.name		= "pkttype",
	.version	= XTABLES_VERSION,
	.size		= XT_ALIGN(sizeof(struct xt_pkttype_info)),
	.userspacesize	= XT_ALIGN(sizeof(struct xt_pkttype_info)),
	.help		= pkttype_help,
	.print		= pkttype_print,
	.save		= pkttype_save,
	.x6_parse	= pkttype_parse,
	.x6_options	= pkttype_opts,
};

void _init(void)
{
	xtables_register_match(&pkttype_match);
}