libipt_realm.c revision 7a0992da44cfb6cab0ccd1beadcf326df8773552 
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
38	realms = xtables_lmap_init(file);
39	if (realms == NULL && errno != ENOENT)
40		fprintf(stderr, "Warning: %s: %s\n", file, strerror(errno));
41}
42
43static void realm_parse(struct xt_option_call *cb)
44{
45	struct xt_realm_info *realminfo = cb->data;
46	int id;
47	char *end;
48
49	xtables_option_parse(cb);
50	realminfo->id = strtoul(cb->arg, &end, 0);
51	if (end != cb->arg && (*end == '/' || *end == '\0')) {
52		if (*end == '/')
53			realminfo->mask = strtoul(end+1, &end, 0);
54		else
55			realminfo->mask = 0xffffffff;
56		if (*end != '\0' || end == cb->arg)
57			xtables_error(PARAMETER_PROBLEM,
58				   "Bad realm value \"%s\"", cb->arg);
59	} else {
60		id = xtables_lmap_name2id(realms, cb->arg);
61		if (id == -1)
62			xtables_error(PARAMETER_PROBLEM,
63				   "Realm \"%s\" not found", cb->arg);
64		realminfo->id = id;
65		realminfo->mask = 0xffffffff;
66	}
67	if (cb->invert)
68		realminfo->invert = 1;
69}
70
71static void
72print_realm(unsigned long id, unsigned long mask, int numeric)
73{
74	const char *name = NULL;
75
76	if (mask != 0xffffffff)
77		printf(" 0x%lx/0x%lx", id, mask);
78	else {
79		if (numeric == 0)
80			name = xtables_lmap_id2name(realms, id);
81		if (name)
82			printf(" %s", name);
83		else
84			printf(" 0x%lx", id);
85	}
86}
87
88static void realm_print(const void *ip, const struct xt_entry_match *match,
89			int numeric)
90{
91	const struct xt_realm_info *ri = (const void *)match->data;
92
93	if (ri->invert)
94		printf(" !");
95
96	printf(" realm");
97	print_realm(ri->id, ri->mask, numeric);
98}
99
100static void realm_save(const void *ip, const struct xt_entry_match *match)
101{
102	const struct xt_realm_info *ri = (const void *)match->data;
103
104	if (ri->invert)
105		printf(" !");
106
107	printf(" --realm");
108	print_realm(ri->id, ri->mask, 0);
109}
110
111static void
112print_realm_xlate(unsigned long id, unsigned long mask,
113		  int numeric, struct xt_xlate *xl, uint32_t op)
114{
115	const char *name = NULL;
116
117	if (mask != 0xffffffff)
118		xt_xlate_add(xl, " and 0x%lx %s 0x%lx", mask,
119			   op == XT_OP_EQ ? "==" : "!=", id);
120	else {
121		if (numeric == 0)
122			name = xtables_lmap_id2name(realms, id);
123		if (name)
124			xt_xlate_add(xl, "%s%s",
125				   op == XT_OP_EQ ? "" : "!= ", name);
126		else
127			xt_xlate_add(xl, " %s0x%lx",
128				   op == XT_OP_EQ ? "" : "!= ", id);
129	}
130}
131
132static int realm_xlate(struct xt_xlate *xl,
133		       const struct xt_xlate_mt_params *params)
134{
135	const struct xt_realm_info *ri = (const void *)params->match->data;
136	enum xt_op op = XT_OP_EQ;
137
138	if (ri->invert)
139		op = XT_OP_NEQ;
140
141	xt_xlate_add(xl, "rtclassid");
142	print_realm_xlate(ri->id, ri->mask, 0, xl, op);
143
144	return 1;
145}
146
147static struct xtables_match realm_mt_reg = {
148	.name		= "realm",
149	.version	= XTABLES_VERSION,
150	.family		= NFPROTO_IPV4,
151	.size		= XT_ALIGN(sizeof(struct xt_realm_info)),
152	.userspacesize	= XT_ALIGN(sizeof(struct xt_realm_info)),
153	.help		= realm_help,
154	.init		= realm_init,
155	.print		= realm_print,
156	.save		= realm_save,
157	.x6_parse	= realm_parse,
158	.x6_options	= realm_opts,
159	.xlate		= realm_xlate,
160};
161
162void _init(void)
163{
164	xtables_register_match(&realm_mt_reg);
165}
166