libxt_TEE.c revision 8532c70fd182057b440b41f013d8021a95bd72b2 
1/*
2 *	"TEE" target extension for iptables
3 *	Copyright © Sebastian Claßen <sebastian.classen [at] freenet.ag>, 2007
4 *	Jan Engelhardt <jengelh [at] medozas de>, 2007 - 2010
5 *
6 *	This program is free software; you can redistribute it and/or
7 *	modify it under the terms of the GNU General Public License; either
8 *	version 2 of the License, or any later version, as published by the
9 *	Free Software Foundation.
10 */
11#include <sys/socket.h>
12#include <getopt.h>
13#include <stdbool.h>
14#include <stdio.h>
15#include <stdlib.h>
16#include <string.h>
17
18#include <arpa/inet.h>
19#include <net/if.h>
20#include <netinet/in.h>
21
22#include <xtables.h>
23#include <linux/netfilter.h>
24#include <linux/netfilter/x_tables.h>
25#include <linux/netfilter/xt_TEE.h>
26
27enum {
28	FLAG_GATEWAY = 1 << 0,
29	FLAG_OIF     = 1 << 1,
30};
31
32static const struct option tee_tg_opts[] = {
33	{.name = "gateway", .has_arg = true, .val = 'g'},
34	{.name = "oif",     .has_arg = true, .val = 'o'},
35	{NULL},
36};
37
38static void tee_tg_help(void)
39{
40	printf(
41"TEE target options:\n"
42"  --gateway IPADDR    Route packet via the gateway given by address\n"
43"  --oif NAME          Include oif in route calculation\n"
44"\n");
45}
46
47static int tee_tg_parse(int c, char **argv, int invert, unsigned int *flags,
48                        const void *entry, struct xt_entry_target **target)
49{
50	struct xt_tee_tginfo *info = (void *)(*target)->data;
51	const struct in_addr *ia;
52
53	switch (c) {
54	case 'g':
55		if (*flags & FLAG_GATEWAY)
56			xtables_error(PARAMETER_PROBLEM,
57			           "Cannot specify --gateway more than once");
58
59		ia = xtables_numeric_to_ipaddr(optarg);
60		if (ia == NULL)
61			xtables_error(PARAMETER_PROBLEM,
62			           "Invalid IP address %s", optarg);
63
64		memcpy(&info->gw, ia, sizeof(*ia));
65		*flags |= FLAG_GATEWAY;
66		return true;
67	case 'o':
68		if (*flags & FLAG_OIF)
69			xtables_error(PARAMETER_PROBLEM,
70				"Cannot specify --oif more than once");
71		if (strlen(optarg) >= sizeof(info->oif))
72			xtables_error(PARAMETER_PROBLEM,
73				"oif name too long");
74		strcpy(info->oif, optarg);
75		*flags |= FLAG_OIF;
76		return true;
77	}
78
79	return false;
80}
81
82static int tee_tg6_parse(int c, char **argv, int invert, unsigned int *flags,
83                         const void *entry, struct xt_entry_target **target)
84{
85	struct xt_tee_tginfo *info = (void *)(*target)->data;
86	const struct in6_addr *ia;
87
88	switch (c) {
89	case 'g':
90		if (*flags & FLAG_GATEWAY)
91			xtables_error(PARAMETER_PROBLEM,
92			           "Cannot specify --gateway more than once");
93
94		ia = xtables_numeric_to_ip6addr(optarg);
95		if (ia == NULL)
96			xtables_error(PARAMETER_PROBLEM,
97			           "Invalid IP address %s", optarg);
98
99		memcpy(&info->gw, ia, sizeof(*ia));
100		*flags |= FLAG_GATEWAY;
101		return true;
102	case 'o':
103		if (*flags & FLAG_OIF)
104			xtables_error(PARAMETER_PROBLEM,
105				"Cannot specify --oif more than once");
106		if (strlen(optarg) >= sizeof(info->oif))
107			xtables_error(PARAMETER_PROBLEM,
108				"oif name too long");
109		strcpy(info->oif, optarg);
110		*flags |= FLAG_OIF;
111		return true;
112	}
113
114	return false;
115}
116
117static void tee_tg_check(unsigned int flags)
118{
119	if (flags == 0)
120		xtables_error(PARAMETER_PROBLEM, "TEE target: "
121		           "--gateway parameter required");
122}
123
124static void tee_tg_print(const void *ip, const struct xt_entry_target *target,
125                         int numeric)
126{
127	const struct xt_tee_tginfo *info = (const void *)target->data;
128
129	if (numeric)
130		printf("TEE gw:%s ", xtables_ipaddr_to_numeric(&info->gw.in));
131	else
132		printf("TEE gw:%s ", xtables_ipaddr_to_anyname(&info->gw.in));
133	if (*info->oif != '\0')
134		printf("oif=%s ", info->oif);
135}
136
137static void tee_tg6_print(const void *ip, const struct xt_entry_target *target,
138                          int numeric)
139{
140	const struct xt_tee_tginfo *info = (const void *)target->data;
141
142	if (numeric)
143		printf("TEE gw:%s ", xtables_ip6addr_to_numeric(&info->gw.in6));
144	else
145		printf("TEE gw:%s ", xtables_ip6addr_to_anyname(&info->gw.in6));
146	if (*info->oif != '\0')
147		printf("oif=%s ", info->oif);
148}
149
150static void tee_tg_save(const void *ip, const struct xt_entry_target *target)
151{
152	const struct xt_tee_tginfo *info = (const void *)target->data;
153
154	printf("--gateway %s ", xtables_ipaddr_to_numeric(&info->gw.in));
155	if (*info->oif != '\0')
156		printf("--oif %s ", info->oif);
157}
158
159static void tee_tg6_save(const void *ip, const struct xt_entry_target *target)
160{
161	const struct xt_tee_tginfo *info = (const void *)target->data;
162
163	printf("--gateway %s ", xtables_ip6addr_to_numeric(&info->gw.in6));
164	if (*info->oif != '\0')
165		printf("--oif %s ", info->oif);
166}
167
168static struct xtables_target tee_tg_reg = {
169	.name          = "TEE",
170	.version       = XTABLES_VERSION,
171	.revision      = 1,
172	.family        = NFPROTO_IPV4,
173	.size          = XT_ALIGN(sizeof(struct xt_tee_tginfo)),
174	.userspacesize = XT_ALIGN(sizeof(struct xt_tee_tginfo)),
175	.help          = tee_tg_help,
176	.parse         = tee_tg_parse,
177	.final_check   = tee_tg_check,
178	.print         = tee_tg_print,
179	.save          = tee_tg_save,
180	.extra_opts    = tee_tg_opts,
181};
182
183static struct xtables_target tee_tg6_reg = {
184	.name          = "TEE",
185	.version       = XTABLES_VERSION,
186	.revision      = 1,
187	.family        = NFPROTO_IPV6,
188	.size          = XT_ALIGN(sizeof(struct xt_tee_tginfo)),
189	.userspacesize = XT_ALIGN(sizeof(struct xt_tee_tginfo)),
190	.help          = tee_tg_help,
191	.parse         = tee_tg6_parse,
192	.final_check   = tee_tg_check,
193	.print         = tee_tg6_print,
194	.save          = tee_tg6_save,
195	.extra_opts    = tee_tg_opts,
196};
197
198static __attribute__((constructor)) void tee_tg_ldr(void)
199{
200	xtables_register_target(&tee_tg_reg);
201	xtables_register_target(&tee_tg6_reg);
202}
203