Loading...
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * "TEE" target extension for Xtables
4 * Copyright © Sebastian Claßen, 2007
5 * Jan Engelhardt, 2007-2010
6 *
7 * based on ipt_ROUTE.c from Cédric de Launois
8 * <delaunois@info.ucl.be>
9 */
10#include <linux/module.h>
11#include <linux/skbuff.h>
12#include <linux/route.h>
13#include <linux/netfilter/x_tables.h>
14#include <net/net_namespace.h>
15#include <net/netns/generic.h>
16#include <net/route.h>
17#include <net/netfilter/ipv4/nf_dup_ipv4.h>
18#include <net/netfilter/ipv6/nf_dup_ipv6.h>
19#include <linux/netfilter/xt_TEE.h>
20
21struct xt_tee_priv {
22 struct list_head list;
23 struct xt_tee_tginfo *tginfo;
24 int oif;
25};
26
27static unsigned int tee_net_id __read_mostly;
28static const union nf_inet_addr tee_zero_address;
29
30struct tee_net {
31 struct list_head priv_list;
32 /* lock protects the priv_list */
33 struct mutex lock;
34};
35
36static unsigned int
37tee_tg4(struct sk_buff *skb, const struct xt_action_param *par)
38{
39 const struct xt_tee_tginfo *info = par->targinfo;
40 int oif = info->priv ? info->priv->oif : 0;
41
42 nf_dup_ipv4(xt_net(par), skb, xt_hooknum(par), &info->gw.in, oif);
43
44 return XT_CONTINUE;
45}
46
47#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
48static unsigned int
49tee_tg6(struct sk_buff *skb, const struct xt_action_param *par)
50{
51 const struct xt_tee_tginfo *info = par->targinfo;
52 int oif = info->priv ? info->priv->oif : 0;
53
54 nf_dup_ipv6(xt_net(par), skb, xt_hooknum(par), &info->gw.in6, oif);
55
56 return XT_CONTINUE;
57}
58#endif
59
60static int tee_netdev_event(struct notifier_block *this, unsigned long event,
61 void *ptr)
62{
63 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
64 struct net *net = dev_net(dev);
65 struct tee_net *tn = net_generic(net, tee_net_id);
66 struct xt_tee_priv *priv;
67
68 mutex_lock(&tn->lock);
69 list_for_each_entry(priv, &tn->priv_list, list) {
70 switch (event) {
71 case NETDEV_REGISTER:
72 if (!strcmp(dev->name, priv->tginfo->oif))
73 priv->oif = dev->ifindex;
74 break;
75 case NETDEV_UNREGISTER:
76 if (dev->ifindex == priv->oif)
77 priv->oif = -1;
78 break;
79 case NETDEV_CHANGENAME:
80 if (!strcmp(dev->name, priv->tginfo->oif))
81 priv->oif = dev->ifindex;
82 else if (dev->ifindex == priv->oif)
83 priv->oif = -1;
84 break;
85 }
86 }
87 mutex_unlock(&tn->lock);
88
89 return NOTIFY_DONE;
90}
91
92static int tee_tg_check(const struct xt_tgchk_param *par)
93{
94 struct tee_net *tn = net_generic(par->net, tee_net_id);
95 struct xt_tee_tginfo *info = par->targinfo;
96 struct xt_tee_priv *priv;
97
98 /* 0.0.0.0 and :: not allowed */
99 if (memcmp(&info->gw, &tee_zero_address,
100 sizeof(tee_zero_address)) == 0)
101 return -EINVAL;
102
103 if (info->oif[0]) {
104 struct net_device *dev;
105
106 if (info->oif[sizeof(info->oif)-1] != '\0')
107 return -EINVAL;
108
109 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
110 if (priv == NULL)
111 return -ENOMEM;
112
113 priv->tginfo = info;
114 priv->oif = -1;
115 info->priv = priv;
116
117 dev = dev_get_by_name(par->net, info->oif);
118 if (dev) {
119 priv->oif = dev->ifindex;
120 dev_put(dev);
121 }
122 mutex_lock(&tn->lock);
123 list_add(&priv->list, &tn->priv_list);
124 mutex_unlock(&tn->lock);
125 } else
126 info->priv = NULL;
127
128 static_key_slow_inc(&xt_tee_enabled);
129 return 0;
130}
131
132static void tee_tg_destroy(const struct xt_tgdtor_param *par)
133{
134 struct tee_net *tn = net_generic(par->net, tee_net_id);
135 struct xt_tee_tginfo *info = par->targinfo;
136
137 if (info->priv) {
138 mutex_lock(&tn->lock);
139 list_del(&info->priv->list);
140 mutex_unlock(&tn->lock);
141 kfree(info->priv);
142 }
143 static_key_slow_dec(&xt_tee_enabled);
144}
145
146static struct xt_target tee_tg_reg[] __read_mostly = {
147 {
148 .name = "TEE",
149 .revision = 1,
150 .family = NFPROTO_IPV4,
151 .target = tee_tg4,
152 .targetsize = sizeof(struct xt_tee_tginfo),
153 .usersize = offsetof(struct xt_tee_tginfo, priv),
154 .checkentry = tee_tg_check,
155 .destroy = tee_tg_destroy,
156 .me = THIS_MODULE,
157 },
158#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
159 {
160 .name = "TEE",
161 .revision = 1,
162 .family = NFPROTO_IPV6,
163 .target = tee_tg6,
164 .targetsize = sizeof(struct xt_tee_tginfo),
165 .usersize = offsetof(struct xt_tee_tginfo, priv),
166 .checkentry = tee_tg_check,
167 .destroy = tee_tg_destroy,
168 .me = THIS_MODULE,
169 },
170#endif
171};
172
173static int __net_init tee_net_init(struct net *net)
174{
175 struct tee_net *tn = net_generic(net, tee_net_id);
176
177 INIT_LIST_HEAD(&tn->priv_list);
178 mutex_init(&tn->lock);
179 return 0;
180}
181
182static struct pernet_operations tee_net_ops = {
183 .init = tee_net_init,
184 .id = &tee_net_id,
185 .size = sizeof(struct tee_net),
186};
187
188static struct notifier_block tee_netdev_notifier = {
189 .notifier_call = tee_netdev_event,
190};
191
192static int __init tee_tg_init(void)
193{
194 int ret;
195
196 ret = register_pernet_subsys(&tee_net_ops);
197 if (ret < 0)
198 return ret;
199
200 ret = xt_register_targets(tee_tg_reg, ARRAY_SIZE(tee_tg_reg));
201 if (ret < 0)
202 goto cleanup_subsys;
203
204 ret = register_netdevice_notifier(&tee_netdev_notifier);
205 if (ret < 0)
206 goto unregister_targets;
207
208 return 0;
209
210unregister_targets:
211 xt_unregister_targets(tee_tg_reg, ARRAY_SIZE(tee_tg_reg));
212cleanup_subsys:
213 unregister_pernet_subsys(&tee_net_ops);
214 return ret;
215}
216
217static void __exit tee_tg_exit(void)
218{
219 unregister_netdevice_notifier(&tee_netdev_notifier);
220 xt_unregister_targets(tee_tg_reg, ARRAY_SIZE(tee_tg_reg));
221 unregister_pernet_subsys(&tee_net_ops);
222}
223
224module_init(tee_tg_init);
225module_exit(tee_tg_exit);
226MODULE_AUTHOR("Sebastian Claßen <sebastian.classen@freenet.ag>");
227MODULE_AUTHOR("Jan Engelhardt <jengelh@medozas.de>");
228MODULE_DESCRIPTION("Xtables: Reroute packet copy");
229MODULE_LICENSE("GPL");
230MODULE_ALIAS("ipt_TEE");
231MODULE_ALIAS("ip6t_TEE");
1/*
2 * "TEE" target extension for Xtables
3 * Copyright © Sebastian Claßen, 2007
4 * Jan Engelhardt, 2007-2010
5 *
6 * based on ipt_ROUTE.c from Cédric de Launois
7 * <delaunois@info.ucl.be>
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License
11 * version 2 or later, as published by the Free Software Foundation.
12 */
13#include <linux/module.h>
14#include <linux/skbuff.h>
15#include <linux/route.h>
16#include <linux/netfilter/x_tables.h>
17#include <net/route.h>
18#include <net/netfilter/ipv4/nf_dup_ipv4.h>
19#include <net/netfilter/ipv6/nf_dup_ipv6.h>
20#include <linux/netfilter/xt_TEE.h>
21
22struct xt_tee_priv {
23 struct list_head list;
24 struct xt_tee_tginfo *tginfo;
25 int oif;
26};
27
28static const union nf_inet_addr tee_zero_address;
29
30static unsigned int
31tee_tg4(struct sk_buff *skb, const struct xt_action_param *par)
32{
33 const struct xt_tee_tginfo *info = par->targinfo;
34 int oif = info->priv ? info->priv->oif : 0;
35
36 nf_dup_ipv4(xt_net(par), skb, xt_hooknum(par), &info->gw.in, oif);
37
38 return XT_CONTINUE;
39}
40
41#if IS_ENABLED(CONFIG_IPV6)
42static unsigned int
43tee_tg6(struct sk_buff *skb, const struct xt_action_param *par)
44{
45 const struct xt_tee_tginfo *info = par->targinfo;
46 int oif = info->priv ? info->priv->oif : 0;
47
48 nf_dup_ipv6(xt_net(par), skb, xt_hooknum(par), &info->gw.in6, oif);
49
50 return XT_CONTINUE;
51}
52#endif
53
54static DEFINE_MUTEX(priv_list_mutex);
55static LIST_HEAD(priv_list);
56
57static int tee_netdev_event(struct notifier_block *this, unsigned long event,
58 void *ptr)
59{
60 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
61 struct xt_tee_priv *priv;
62
63 mutex_lock(&priv_list_mutex);
64 list_for_each_entry(priv, &priv_list, list) {
65 switch (event) {
66 case NETDEV_REGISTER:
67 if (!strcmp(dev->name, priv->tginfo->oif))
68 priv->oif = dev->ifindex;
69 break;
70 case NETDEV_UNREGISTER:
71 if (dev->ifindex == priv->oif)
72 priv->oif = -1;
73 break;
74 case NETDEV_CHANGENAME:
75 if (!strcmp(dev->name, priv->tginfo->oif))
76 priv->oif = dev->ifindex;
77 else if (dev->ifindex == priv->oif)
78 priv->oif = -1;
79 break;
80 }
81 }
82 mutex_unlock(&priv_list_mutex);
83
84 return NOTIFY_DONE;
85}
86
87static int tee_tg_check(const struct xt_tgchk_param *par)
88{
89 struct xt_tee_tginfo *info = par->targinfo;
90 struct xt_tee_priv *priv;
91
92 /* 0.0.0.0 and :: not allowed */
93 if (memcmp(&info->gw, &tee_zero_address,
94 sizeof(tee_zero_address)) == 0)
95 return -EINVAL;
96
97 if (info->oif[0]) {
98 if (info->oif[sizeof(info->oif)-1] != '\0')
99 return -EINVAL;
100
101 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
102 if (priv == NULL)
103 return -ENOMEM;
104
105 priv->tginfo = info;
106 priv->oif = -1;
107 info->priv = priv;
108
109 mutex_lock(&priv_list_mutex);
110 list_add(&priv->list, &priv_list);
111 mutex_unlock(&priv_list_mutex);
112 } else
113 info->priv = NULL;
114
115 static_key_slow_inc(&xt_tee_enabled);
116 return 0;
117}
118
119static void tee_tg_destroy(const struct xt_tgdtor_param *par)
120{
121 struct xt_tee_tginfo *info = par->targinfo;
122
123 if (info->priv) {
124 mutex_lock(&priv_list_mutex);
125 list_del(&info->priv->list);
126 mutex_unlock(&priv_list_mutex);
127 kfree(info->priv);
128 }
129 static_key_slow_dec(&xt_tee_enabled);
130}
131
132static struct xt_target tee_tg_reg[] __read_mostly = {
133 {
134 .name = "TEE",
135 .revision = 1,
136 .family = NFPROTO_IPV4,
137 .target = tee_tg4,
138 .targetsize = sizeof(struct xt_tee_tginfo),
139 .usersize = offsetof(struct xt_tee_tginfo, priv),
140 .checkentry = tee_tg_check,
141 .destroy = tee_tg_destroy,
142 .me = THIS_MODULE,
143 },
144#if IS_ENABLED(CONFIG_IPV6)
145 {
146 .name = "TEE",
147 .revision = 1,
148 .family = NFPROTO_IPV6,
149 .target = tee_tg6,
150 .targetsize = sizeof(struct xt_tee_tginfo),
151 .usersize = offsetof(struct xt_tee_tginfo, priv),
152 .checkentry = tee_tg_check,
153 .destroy = tee_tg_destroy,
154 .me = THIS_MODULE,
155 },
156#endif
157};
158
159static struct notifier_block tee_netdev_notifier = {
160 .notifier_call = tee_netdev_event,
161};
162
163static int __init tee_tg_init(void)
164{
165 int ret;
166
167 ret = xt_register_targets(tee_tg_reg, ARRAY_SIZE(tee_tg_reg));
168 if (ret)
169 return ret;
170 ret = register_netdevice_notifier(&tee_netdev_notifier);
171 if (ret) {
172 xt_unregister_targets(tee_tg_reg, ARRAY_SIZE(tee_tg_reg));
173 return ret;
174 }
175
176 return 0;
177}
178
179static void __exit tee_tg_exit(void)
180{
181 unregister_netdevice_notifier(&tee_netdev_notifier);
182 xt_unregister_targets(tee_tg_reg, ARRAY_SIZE(tee_tg_reg));
183}
184
185module_init(tee_tg_init);
186module_exit(tee_tg_exit);
187MODULE_AUTHOR("Sebastian Claßen <sebastian.classen@freenet.ag>");
188MODULE_AUTHOR("Jan Engelhardt <jengelh@medozas.de>");
189MODULE_DESCRIPTION("Xtables: Reroute packet copy");
190MODULE_LICENSE("GPL");
191MODULE_ALIAS("ipt_TEE");
192MODULE_ALIAS("ip6t_TEE");