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Thomas Gleixner3a63cbb2019-05-19 15:51:33 +02001// SPDX-License-Identifier: GPL-2.0-or-later
Jan Engelhardte281b192010-04-19 14:17:47 +02002/*
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>
Jan Engelhardte281b192010-04-19 14:17:47 +02009 */
Jan Engelhardte281b192010-04-19 14:17:47 +020010#include <linux/module.h>
Jan Engelhardte281b192010-04-19 14:17:47 +020011#include <linux/skbuff.h>
Pablo Neira Ayusobbde9fc2015-05-31 17:54:44 +020012#include <linux/route.h>
Jan Engelhardte281b192010-04-19 14:17:47 +020013#include <linux/netfilter/x_tables.h>
Taehee Yoof24d2d42018-10-07 00:09:18 +090014#include <net/net_namespace.h>
15#include <net/netns/generic.h>
Pablo Neira Ayusobbde9fc2015-05-31 17:54:44 +020016#include <net/route.h>
17#include <net/netfilter/ipv4/nf_dup_ipv4.h>
18#include <net/netfilter/ipv6/nf_dup_ipv6.h>
Jan Engelhardte281b192010-04-19 14:17:47 +020019#include <linux/netfilter/xt_TEE.h>
Jan Engelhardte281b192010-04-19 14:17:47 +020020
Patrick McHardy22265a52010-04-20 15:07:32 +020021struct xt_tee_priv {
Kirill Tkhai9e2f6c52018-03-29 17:03:35 +030022 struct list_head list;
Patrick McHardy22265a52010-04-20 15:07:32 +020023 struct xt_tee_tginfo *tginfo;
24 int oif;
25};
26
Taehee Yoof24d2d42018-10-07 00:09:18 +090027static unsigned int tee_net_id __read_mostly;
Jan Engelhardte281b192010-04-19 14:17:47 +020028static const union nf_inet_addr tee_zero_address;
29
Taehee Yoof24d2d42018-10-07 00:09:18 +090030struct tee_net {
31 struct list_head priv_list;
32 /* lock protects the priv_list */
33 struct mutex lock;
34};
35
Jan Engelhardte281b192010-04-19 14:17:47 +020036static unsigned int
Jan Engelhardt4b560b42009-07-05 19:43:26 +020037tee_tg4(struct sk_buff *skb, const struct xt_action_param *par)
Jan Engelhardte281b192010-04-19 14:17:47 +020038{
39 const struct xt_tee_tginfo *info = par->targinfo;
Eric Dumazet45efccd2015-10-19 18:02:01 -070040 int oif = info->priv ? info->priv->oif : 0;
Jan Engelhardte281b192010-04-19 14:17:47 +020041
Pablo Neira Ayuso613dbd92016-11-03 10:56:21 +010042 nf_dup_ipv4(xt_net(par), skb, xt_hooknum(par), &info->gw.in, oif);
Jan Engelhardte281b192010-04-19 14:17:47 +020043
Jan Engelhardte281b192010-04-19 14:17:47 +020044 return XT_CONTINUE;
45}
46
Máté Eckl5d400a42018-07-10 16:01:28 +020047#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
Jan Engelhardte281b192010-04-19 14:17:47 +020048static unsigned int
Jan Engelhardt4b560b42009-07-05 19:43:26 +020049tee_tg6(struct sk_buff *skb, const struct xt_action_param *par)
Jan Engelhardte281b192010-04-19 14:17:47 +020050{
51 const struct xt_tee_tginfo *info = par->targinfo;
Eric Dumazet45efccd2015-10-19 18:02:01 -070052 int oif = info->priv ? info->priv->oif : 0;
Jan Engelhardte281b192010-04-19 14:17:47 +020053
Pablo Neira Ayuso613dbd92016-11-03 10:56:21 +010054 nf_dup_ipv6(xt_net(par), skb, xt_hooknum(par), &info->gw.in6, oif);
Jan Engelhardte281b192010-04-19 14:17:47 +020055
Jan Engelhardte281b192010-04-19 14:17:47 +020056 return XT_CONTINUE;
57}
Eric Dumazetdfd56b82011-12-10 09:48:31 +000058#endif
Jan Engelhardte281b192010-04-19 14:17:47 +020059
Patrick McHardy22265a52010-04-20 15:07:32 +020060static int tee_netdev_event(struct notifier_block *this, unsigned long event,
61 void *ptr)
62{
Jiri Pirko351638e2013-05-28 01:30:21 +000063 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
Taehee Yoof24d2d42018-10-07 00:09:18 +090064 struct net *net = dev_net(dev);
65 struct tee_net *tn = net_generic(net, tee_net_id);
Patrick McHardy22265a52010-04-20 15:07:32 +020066 struct xt_tee_priv *priv;
67
Taehee Yoof24d2d42018-10-07 00:09:18 +090068 mutex_lock(&tn->lock);
69 list_for_each_entry(priv, &tn->priv_list, list) {
Kirill Tkhai9e2f6c52018-03-29 17:03:35 +030070 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 }
Patrick McHardy22265a52010-04-20 15:07:32 +020086 }
Taehee Yoof24d2d42018-10-07 00:09:18 +090087 mutex_unlock(&tn->lock);
Patrick McHardy22265a52010-04-20 15:07:32 +020088
89 return NOTIFY_DONE;
90}
91
Jan Engelhardte281b192010-04-19 14:17:47 +020092static int tee_tg_check(const struct xt_tgchk_param *par)
93{
Taehee Yoof24d2d42018-10-07 00:09:18 +090094 struct tee_net *tn = net_generic(par->net, tee_net_id);
Patrick McHardy22265a52010-04-20 15:07:32 +020095 struct xt_tee_tginfo *info = par->targinfo;
96 struct xt_tee_priv *priv;
Jan Engelhardte281b192010-04-19 14:17:47 +020097
Jan Engelhardte281b192010-04-19 14:17:47 +020098 /* 0.0.0.0 and :: not allowed */
Patrick McHardy22265a52010-04-20 15:07:32 +020099 if (memcmp(&info->gw, &tee_zero_address,
100 sizeof(tee_zero_address)) == 0)
101 return -EINVAL;
102
103 if (info->oif[0]) {
Taehee Yoo18c0ab82018-10-07 00:09:32 +0900104 struct net_device *dev;
105
Patrick McHardy22265a52010-04-20 15:07:32 +0200106 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;
Patrick McHardy22265a52010-04-20 15:07:32 +0200115 info->priv = priv;
116
Taehee Yoo18c0ab82018-10-07 00:09:32 +0900117 dev = dev_get_by_name(par->net, info->oif);
118 if (dev) {
119 priv->oif = dev->ifindex;
120 dev_put(dev);
121 }
Taehee Yoof24d2d42018-10-07 00:09:18 +0900122 mutex_lock(&tn->lock);
123 list_add(&priv->list, &tn->priv_list);
124 mutex_unlock(&tn->lock);
Patrick McHardy22265a52010-04-20 15:07:32 +0200125 } else
126 info->priv = NULL;
127
Florian Westphaldcebd312015-07-14 17:51:09 +0200128 static_key_slow_inc(&xt_tee_enabled);
Patrick McHardy22265a52010-04-20 15:07:32 +0200129 return 0;
130}
131
132static void tee_tg_destroy(const struct xt_tgdtor_param *par)
133{
Taehee Yoof24d2d42018-10-07 00:09:18 +0900134 struct tee_net *tn = net_generic(par->net, tee_net_id);
Patrick McHardy22265a52010-04-20 15:07:32 +0200135 struct xt_tee_tginfo *info = par->targinfo;
136
137 if (info->priv) {
Taehee Yoof24d2d42018-10-07 00:09:18 +0900138 mutex_lock(&tn->lock);
Kirill Tkhai9e2f6c52018-03-29 17:03:35 +0300139 list_del(&info->priv->list);
Taehee Yoof24d2d42018-10-07 00:09:18 +0900140 mutex_unlock(&tn->lock);
Patrick McHardy22265a52010-04-20 15:07:32 +0200141 kfree(info->priv);
142 }
Florian Westphaldcebd312015-07-14 17:51:09 +0200143 static_key_slow_dec(&xt_tee_enabled);
Jan Engelhardte281b192010-04-19 14:17:47 +0200144}
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),
Willem de Bruijnec231892017-01-02 17:19:46 -0500153 .usersize = offsetof(struct xt_tee_tginfo, priv),
Jan Engelhardte281b192010-04-19 14:17:47 +0200154 .checkentry = tee_tg_check,
Patrick McHardy22265a52010-04-20 15:07:32 +0200155 .destroy = tee_tg_destroy,
Jan Engelhardte281b192010-04-19 14:17:47 +0200156 .me = THIS_MODULE,
157 },
Máté Eckl5d400a42018-07-10 16:01:28 +0200158#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
Jan Engelhardte281b192010-04-19 14:17:47 +0200159 {
160 .name = "TEE",
161 .revision = 1,
162 .family = NFPROTO_IPV6,
163 .target = tee_tg6,
164 .targetsize = sizeof(struct xt_tee_tginfo),
Willem de Bruijnec231892017-01-02 17:19:46 -0500165 .usersize = offsetof(struct xt_tee_tginfo, priv),
Jan Engelhardte281b192010-04-19 14:17:47 +0200166 .checkentry = tee_tg_check,
Patrick McHardy22265a52010-04-20 15:07:32 +0200167 .destroy = tee_tg_destroy,
Jan Engelhardte281b192010-04-19 14:17:47 +0200168 .me = THIS_MODULE,
169 },
170#endif
171};
172
Taehee Yoof24d2d42018-10-07 00:09:18 +0900173static 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
Kirill Tkhai9e2f6c52018-03-29 17:03:35 +0300188static struct notifier_block tee_netdev_notifier = {
189 .notifier_call = tee_netdev_event,
190};
191
Jan Engelhardte281b192010-04-19 14:17:47 +0200192static int __init tee_tg_init(void)
193{
Kirill Tkhai9e2f6c52018-03-29 17:03:35 +0300194 int ret;
195
Taehee Yoof24d2d42018-10-07 00:09:18 +0900196 ret = register_pernet_subsys(&tee_net_ops);
197 if (ret < 0)
198 return ret;
199
Kirill Tkhai9e2f6c52018-03-29 17:03:35 +0300200 ret = xt_register_targets(tee_tg_reg, ARRAY_SIZE(tee_tg_reg));
Taehee Yoof24d2d42018-10-07 00:09:18 +0900201 if (ret < 0)
202 goto cleanup_subsys;
203
Kirill Tkhai9e2f6c52018-03-29 17:03:35 +0300204 ret = register_netdevice_notifier(&tee_netdev_notifier);
Taehee Yoof24d2d42018-10-07 00:09:18 +0900205 if (ret < 0)
206 goto unregister_targets;
Kirill Tkhai9e2f6c52018-03-29 17:03:35 +0300207
208 return 0;
Taehee Yoof24d2d42018-10-07 00:09:18 +0900209
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;
Jan Engelhardte281b192010-04-19 14:17:47 +0200215}
216
217static void __exit tee_tg_exit(void)
218{
Kirill Tkhai9e2f6c52018-03-29 17:03:35 +0300219 unregister_netdevice_notifier(&tee_netdev_notifier);
Jan Engelhardte281b192010-04-19 14:17:47 +0200220 xt_unregister_targets(tee_tg_reg, ARRAY_SIZE(tee_tg_reg));
Taehee Yoof24d2d42018-10-07 00:09:18 +0900221 unregister_pernet_subsys(&tee_net_ops);
Jan Engelhardte281b192010-04-19 14:17:47 +0200222}
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");