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
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
|
/*
* "TEE" target extension for Xtables
* Copyright © Sebastian Claßen, 2007
* Jan Engelhardt, 2007-2010
*
* based on ipt_ROUTE.c from Cédric de Launois
* <delaunois@info.ucl.be>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* version 2 or later, as published by the Free Software Foundation.
*/
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/route.h>
#include <linux/netfilter/x_tables.h>
#include <net/net_namespace.h>
#include <net/netns/generic.h>
#include <net/route.h>
#include <net/netfilter/ipv4/nf_dup_ipv4.h>
#include <net/netfilter/ipv6/nf_dup_ipv6.h>
#include <linux/netfilter/xt_TEE.h>
struct xt_tee_priv {
struct list_head list;
struct xt_tee_tginfo *tginfo;
int oif;
};
static unsigned int tee_net_id __read_mostly;
static const union nf_inet_addr tee_zero_address;
struct tee_net {
struct list_head priv_list;
/* lock protects the priv_list */
struct mutex lock;
};
static unsigned int
tee_tg4(struct sk_buff *skb, const struct xt_action_param *par)
{
const struct xt_tee_tginfo *info = par->targinfo;
int oif = info->priv ? info->priv->oif : 0;
nf_dup_ipv4(xt_net(par), skb, xt_hooknum(par), &info->gw.in, oif);
return XT_CONTINUE;
}
#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
static unsigned int
tee_tg6(struct sk_buff *skb, const struct xt_action_param *par)
{
const struct xt_tee_tginfo *info = par->targinfo;
int oif = info->priv ? info->priv->oif : 0;
nf_dup_ipv6(xt_net(par), skb, xt_hooknum(par), &info->gw.in6, oif);
return XT_CONTINUE;
}
#endif
static int tee_netdev_event(struct notifier_block *this, unsigned long event,
void *ptr)
{
struct net_device *dev = netdev_notifier_info_to_dev(ptr);
struct net *net = dev_net(dev);
struct tee_net *tn = net_generic(net, tee_net_id);
struct xt_tee_priv *priv;
mutex_lock(&tn->lock);
list_for_each_entry(priv, &tn->priv_list, list) {
switch (event) {
case NETDEV_REGISTER:
if (!strcmp(dev->name, priv->tginfo->oif))
priv->oif = dev->ifindex;
break;
case NETDEV_UNREGISTER:
if (dev->ifindex == priv->oif)
priv->oif = -1;
break;
case NETDEV_CHANGENAME:
if (!strcmp(dev->name, priv->tginfo->oif))
priv->oif = dev->ifindex;
else if (dev->ifindex == priv->oif)
priv->oif = -1;
break;
}
}
mutex_unlock(&tn->lock);
return NOTIFY_DONE;
}
static int tee_tg_check(const struct xt_tgchk_param *par)
{
struct tee_net *tn = net_generic(par->net, tee_net_id);
struct xt_tee_tginfo *info = par->targinfo;
struct xt_tee_priv *priv;
/* 0.0.0.0 and :: not allowed */
if (memcmp(&info->gw, &tee_zero_address,
sizeof(tee_zero_address)) == 0)
return -EINVAL;
if (info->oif[0]) {
struct net_device *dev;
if (info->oif[sizeof(info->oif)-1] != '\0')
return -EINVAL;
priv = kzalloc(sizeof(*priv), GFP_KERNEL);
if (priv == NULL)
return -ENOMEM;
priv->tginfo = info;
priv->oif = -1;
info->priv = priv;
dev = dev_get_by_name(par->net, info->oif);
if (dev) {
priv->oif = dev->ifindex;
dev_put(dev);
}
mutex_lock(&tn->lock);
list_add(&priv->list, &tn->priv_list);
mutex_unlock(&tn->lock);
} else
info->priv = NULL;
static_key_slow_inc(&xt_tee_enabled);
return 0;
}
static void tee_tg_destroy(const struct xt_tgdtor_param *par)
{
struct tee_net *tn = net_generic(par->net, tee_net_id);
struct xt_tee_tginfo *info = par->targinfo;
if (info->priv) {
mutex_lock(&tn->lock);
list_del(&info->priv->list);
mutex_unlock(&tn->lock);
kfree(info->priv);
}
static_key_slow_dec(&xt_tee_enabled);
}
static struct xt_target tee_tg_reg[] __read_mostly = {
{
.name = "TEE",
.revision = 1,
.family = NFPROTO_IPV4,
.target = tee_tg4,
.targetsize = sizeof(struct xt_tee_tginfo),
.usersize = offsetof(struct xt_tee_tginfo, priv),
.checkentry = tee_tg_check,
.destroy = tee_tg_destroy,
.me = THIS_MODULE,
},
#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
{
.name = "TEE",
.revision = 1,
.family = NFPROTO_IPV6,
.target = tee_tg6,
.targetsize = sizeof(struct xt_tee_tginfo),
.usersize = offsetof(struct xt_tee_tginfo, priv),
.checkentry = tee_tg_check,
.destroy = tee_tg_destroy,
.me = THIS_MODULE,
},
#endif
};
static int __net_init tee_net_init(struct net *net)
{
struct tee_net *tn = net_generic(net, tee_net_id);
INIT_LIST_HEAD(&tn->priv_list);
mutex_init(&tn->lock);
return 0;
}
static struct pernet_operations tee_net_ops = {
.init = tee_net_init,
.id = &tee_net_id,
.size = sizeof(struct tee_net),
};
static struct notifier_block tee_netdev_notifier = {
.notifier_call = tee_netdev_event,
};
static int __init tee_tg_init(void)
{
int ret;
ret = register_pernet_subsys(&tee_net_ops);
if (ret < 0)
return ret;
ret = xt_register_targets(tee_tg_reg, ARRAY_SIZE(tee_tg_reg));
if (ret < 0)
goto cleanup_subsys;
ret = register_netdevice_notifier(&tee_netdev_notifier);
if (ret < 0)
goto unregister_targets;
return 0;
unregister_targets:
xt_unregister_targets(tee_tg_reg, ARRAY_SIZE(tee_tg_reg));
cleanup_subsys:
unregister_pernet_subsys(&tee_net_ops);
return ret;
}
static void __exit tee_tg_exit(void)
{
unregister_netdevice_notifier(&tee_netdev_notifier);
xt_unregister_targets(tee_tg_reg, ARRAY_SIZE(tee_tg_reg));
unregister_pernet_subsys(&tee_net_ops);
}
module_init(tee_tg_init);
module_exit(tee_tg_exit);
MODULE_AUTHOR("Sebastian Claßen <sebastian.classen@freenet.ag>");
MODULE_AUTHOR("Jan Engelhardt <jengelh@medozas.de>");
MODULE_DESCRIPTION("Xtables: Reroute packet copy");
MODULE_LICENSE("GPL");
MODULE_ALIAS("ipt_TEE");
MODULE_ALIAS("ip6t_TEE");
|
