Commit | Line | Data |
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e281b198 JE |
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 | */ | |
e281b198 | 13 | #include <linux/module.h> |
e281b198 | 14 | #include <linux/skbuff.h> |
bbde9fc1 | 15 | #include <linux/route.h> |
e281b198 | 16 | #include <linux/netfilter/x_tables.h> |
bbde9fc1 PNA |
17 | #include <net/route.h> |
18 | #include <net/netfilter/ipv4/nf_dup_ipv4.h> | |
19 | #include <net/netfilter/ipv6/nf_dup_ipv6.h> | |
e281b198 | 20 | #include <linux/netfilter/xt_TEE.h> |
e281b198 | 21 | |
22265a5c | 22 | struct xt_tee_priv { |
9e2f6c5d | 23 | struct list_head list; |
22265a5c PM |
24 | struct xt_tee_tginfo *tginfo; |
25 | int oif; | |
26 | }; | |
27 | ||
e281b198 JE |
28 | static const union nf_inet_addr tee_zero_address; |
29 | ||
e281b198 | 30 | static unsigned int |
4b560b44 | 31 | tee_tg4(struct sk_buff *skb, const struct xt_action_param *par) |
e281b198 JE |
32 | { |
33 | const struct xt_tee_tginfo *info = par->targinfo; | |
45efccdb | 34 | int oif = info->priv ? info->priv->oif : 0; |
e281b198 | 35 | |
613dbd95 | 36 | nf_dup_ipv4(xt_net(par), skb, xt_hooknum(par), &info->gw.in, oif); |
e281b198 | 37 | |
e281b198 JE |
38 | return XT_CONTINUE; |
39 | } | |
40 | ||
08a7f5d3 | 41 | #if IS_ENABLED(CONFIG_IPV6) |
e281b198 | 42 | static unsigned int |
4b560b44 | 43 | tee_tg6(struct sk_buff *skb, const struct xt_action_param *par) |
e281b198 JE |
44 | { |
45 | const struct xt_tee_tginfo *info = par->targinfo; | |
45efccdb | 46 | int oif = info->priv ? info->priv->oif : 0; |
e281b198 | 47 | |
613dbd95 | 48 | nf_dup_ipv6(xt_net(par), skb, xt_hooknum(par), &info->gw.in6, oif); |
e281b198 | 49 | |
e281b198 JE |
50 | return XT_CONTINUE; |
51 | } | |
dfd56b8b | 52 | #endif |
e281b198 | 53 | |
9e2f6c5d KT |
54 | static DEFINE_MUTEX(priv_list_mutex); |
55 | static LIST_HEAD(priv_list); | |
56 | ||
22265a5c PM |
57 | static int tee_netdev_event(struct notifier_block *this, unsigned long event, |
58 | void *ptr) | |
59 | { | |
351638e7 | 60 | struct net_device *dev = netdev_notifier_info_to_dev(ptr); |
22265a5c PM |
61 | struct xt_tee_priv *priv; |
62 | ||
9e2f6c5d KT |
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 | } | |
22265a5c | 81 | } |
9e2f6c5d | 82 | mutex_unlock(&priv_list_mutex); |
22265a5c PM |
83 | |
84 | return NOTIFY_DONE; | |
85 | } | |
86 | ||
e281b198 JE |
87 | static int tee_tg_check(const struct xt_tgchk_param *par) |
88 | { | |
22265a5c PM |
89 | struct xt_tee_tginfo *info = par->targinfo; |
90 | struct xt_tee_priv *priv; | |
e281b198 | 91 | |
e281b198 | 92 | /* 0.0.0.0 and :: not allowed */ |
22265a5c PM |
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; | |
22265a5c PM |
107 | info->priv = priv; |
108 | ||
9e2f6c5d KT |
109 | mutex_lock(&priv_list_mutex); |
110 | list_add(&priv->list, &priv_list); | |
111 | mutex_unlock(&priv_list_mutex); | |
22265a5c PM |
112 | } else |
113 | info->priv = NULL; | |
114 | ||
dcebd315 | 115 | static_key_slow_inc(&xt_tee_enabled); |
22265a5c PM |
116 | return 0; |
117 | } | |
118 | ||
119 | static void tee_tg_destroy(const struct xt_tgdtor_param *par) | |
120 | { | |
121 | struct xt_tee_tginfo *info = par->targinfo; | |
122 | ||
123 | if (info->priv) { | |
9e2f6c5d KT |
124 | mutex_lock(&priv_list_mutex); |
125 | list_del(&info->priv->list); | |
126 | mutex_unlock(&priv_list_mutex); | |
22265a5c PM |
127 | kfree(info->priv); |
128 | } | |
dcebd315 | 129 | static_key_slow_dec(&xt_tee_enabled); |
e281b198 JE |
130 | } |
131 | ||
132 | static 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), | |
ec231890 | 139 | .usersize = offsetof(struct xt_tee_tginfo, priv), |
e281b198 | 140 | .checkentry = tee_tg_check, |
22265a5c | 141 | .destroy = tee_tg_destroy, |
e281b198 JE |
142 | .me = THIS_MODULE, |
143 | }, | |
08a7f5d3 | 144 | #if IS_ENABLED(CONFIG_IPV6) |
e281b198 JE |
145 | { |
146 | .name = "TEE", | |
147 | .revision = 1, | |
148 | .family = NFPROTO_IPV6, | |
149 | .target = tee_tg6, | |
150 | .targetsize = sizeof(struct xt_tee_tginfo), | |
ec231890 | 151 | .usersize = offsetof(struct xt_tee_tginfo, priv), |
e281b198 | 152 | .checkentry = tee_tg_check, |
22265a5c | 153 | .destroy = tee_tg_destroy, |
e281b198 JE |
154 | .me = THIS_MODULE, |
155 | }, | |
156 | #endif | |
157 | }; | |
158 | ||
9e2f6c5d KT |
159 | static struct notifier_block tee_netdev_notifier = { |
160 | .notifier_call = tee_netdev_event, | |
161 | }; | |
162 | ||
e281b198 JE |
163 | static int __init tee_tg_init(void) |
164 | { | |
9e2f6c5d KT |
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; | |
e281b198 JE |
177 | } |
178 | ||
179 | static void __exit tee_tg_exit(void) | |
180 | { | |
9e2f6c5d | 181 | unregister_netdevice_notifier(&tee_netdev_notifier); |
e281b198 JE |
182 | xt_unregister_targets(tee_tg_reg, ARRAY_SIZE(tee_tg_reg)); |
183 | } | |
184 | ||
185 | module_init(tee_tg_init); | |
186 | module_exit(tee_tg_exit); | |
187 | MODULE_AUTHOR("Sebastian Claßen <sebastian.classen@freenet.ag>"); | |
188 | MODULE_AUTHOR("Jan Engelhardt <jengelh@medozas.de>"); | |
189 | MODULE_DESCRIPTION("Xtables: Reroute packet copy"); | |
190 | MODULE_LICENSE("GPL"); | |
191 | MODULE_ALIAS("ipt_TEE"); | |
192 | MODULE_ALIAS("ip6t_TEE"); |