libipt_realm.c revision 14da56743c6cdf25da35b7b5ca7a5d201771990d 
1#include <stdio.h>
2#include <string.h>
3#include <stdlib.h>
4#include <errno.h>
5#if defined(__GLIBC__) && __GLIBC__ == 2
6#include <net/ethernet.h>
7#else
8#include <linux/if_ether.h>
9#endif
10#include <xtables.h>
11#include <linux/netfilter_ipv4/ipt_realm.h>
12
13enum {
14	O_REALM = 0,
15};
16
17static void realm_help(void)
18{
19	printf(
20"realm match options:\n"
21"[!] --realm value[/mask]\n"
22"				Match realm\n");
23}
24
25static const struct xt_option_entry realm_opts[] = {
26	{.name = "realm", .id = O_REALM, .type = XTTYPE_STRING,
27	 .flags = XTOPT_MAND | XTOPT_INVERT},
28	XTOPT_TABLEEND,
29};
30
31/* array of realms from /etc/iproute2/rt_realms */
32static struct xtables_lmap *realms;
33
34static void realm_init(struct xt_entry_match *m)
35{
36	const char file[] = "/etc/iproute2/rt_realms";
37	realms = xtables_lmap_init(file);
38	if (realms == NULL && errno != ENOENT)
39		fprintf(stderr, "Warning: %s: %s\n", file, strerror(errno));
40}
41
42static void realm_parse(struct xt_option_call *cb)
43{
44	struct xt_realm_info *realminfo = cb->data;
45	int id;
46	char *end;
47
48	xtables_option_parse(cb);
49	realminfo->id = strtoul(cb->arg, &end, 0);
50	if (end != cb->arg && (*end == '/' || *end == '\0')) {
51		if (*end == '/')
52			realminfo->mask = strtoul(end+1, &end, 0);
53		else
54			realminfo->mask = 0xffffffff;
55		if (*end != '\0' || end == cb->arg)
56			xtables_error(PARAMETER_PROBLEM,
57				   "Bad realm value \"%s\"", cb->arg);
58	} else {
59		id = xtables_lmap_name2id(realms, cb->arg);
60		if (id == -1)
61			xtables_error(PARAMETER_PROBLEM,
62				   "Realm \"%s\" not found", cb->arg);
63		realminfo->id = id;
64		realminfo->mask = 0xffffffff;
65	}
66	if (cb->invert)
67		realminfo->invert = 1;
68}
69
70static void
71print_realm(unsigned long id, unsigned long mask, int numeric)
72{
73	const char* name = NULL;
74
75	if (mask != 0xffffffff)
76		printf(" 0x%lx/0x%lx", id, mask);
77	else {
78		if (numeric == 0)
79			name = xtables_lmap_id2name(realms, id);
80		if (name)
81			printf(" %s", name);
82		else
83			printf(" 0x%lx", id);
84	}
85}
86
87static void realm_print(const void *ip, const struct xt_entry_match *match,
88                        int numeric)
89{
90	const struct xt_realm_info *ri = (const void *)match->data;
91
92	if (ri->invert)
93		printf(" !");
94
95	printf(" realm");
96	print_realm(ri->id, ri->mask, numeric);
97}
98
99static void realm_save(const void *ip, const struct xt_entry_match *match)
100{
101	const struct xt_realm_info *ri = (const void *)match->data;
102
103	if (ri->invert)
104		printf(" !");
105
106	printf(" --realm");
107	print_realm(ri->id, ri->mask, 0);
108}
109
110static struct xtables_match realm_mt_reg = {
111	.name		= "realm",
112	.version	= XTABLES_VERSION,
113	.family		= NFPROTO_IPV4,
114	.size		= XT_ALIGN(sizeof(struct xt_realm_info)),
115	.userspacesize	= XT_ALIGN(sizeof(struct xt_realm_info)),
116	.help		= realm_help,
117	.init		= realm_init,
118	.print		= realm_print,
119	.save		= realm_save,
120	.x6_parse	= realm_parse,
121	.x6_options	= realm_opts,
122};
123
124void _init(void)
125{
126	xtables_register_match(&realm_mt_reg);
127}
128