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 PM |
22 | struct xt_tee_priv { |
23 | struct notifier_block notifier; | |
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; | |
e281b198 | 34 | |
bbde9fc1 | 35 | nf_dup_ipv4(skb, par->hooknum, &info->gw.in, info->priv->oif); |
e281b198 | 36 | |
e281b198 JE |
37 | return XT_CONTINUE; |
38 | } | |
39 | ||
116984a3 | 40 | #if IS_ENABLED(CONFIG_NF_DUP_IPV6) |
e281b198 | 41 | static unsigned int |
4b560b44 | 42 | tee_tg6(struct sk_buff *skb, const struct xt_action_param *par) |
e281b198 JE |
43 | { |
44 | const struct xt_tee_tginfo *info = par->targinfo; | |
45 | ||
bbde9fc1 | 46 | nf_dup_ipv6(skb, par->hooknum, &info->gw.in6, info->priv->oif); |
e281b198 | 47 | |
e281b198 JE |
48 | return XT_CONTINUE; |
49 | } | |
dfd56b8b | 50 | #endif |
e281b198 | 51 | |
22265a5c PM |
52 | static int tee_netdev_event(struct notifier_block *this, unsigned long event, |
53 | void *ptr) | |
54 | { | |
351638e7 | 55 | struct net_device *dev = netdev_notifier_info_to_dev(ptr); |
22265a5c PM |
56 | struct xt_tee_priv *priv; |
57 | ||
58 | priv = container_of(this, struct xt_tee_priv, notifier); | |
59 | switch (event) { | |
60 | case NETDEV_REGISTER: | |
61 | if (!strcmp(dev->name, priv->tginfo->oif)) | |
62 | priv->oif = dev->ifindex; | |
63 | break; | |
64 | case NETDEV_UNREGISTER: | |
65 | if (dev->ifindex == priv->oif) | |
66 | priv->oif = -1; | |
67 | break; | |
68 | case NETDEV_CHANGENAME: | |
69 | if (!strcmp(dev->name, priv->tginfo->oif)) | |
70 | priv->oif = dev->ifindex; | |
71 | else if (dev->ifindex == priv->oif) | |
72 | priv->oif = -1; | |
73 | break; | |
74 | } | |
75 | ||
76 | return NOTIFY_DONE; | |
77 | } | |
78 | ||
e281b198 JE |
79 | static int tee_tg_check(const struct xt_tgchk_param *par) |
80 | { | |
22265a5c PM |
81 | struct xt_tee_tginfo *info = par->targinfo; |
82 | struct xt_tee_priv *priv; | |
e281b198 | 83 | |
e281b198 | 84 | /* 0.0.0.0 and :: not allowed */ |
22265a5c PM |
85 | if (memcmp(&info->gw, &tee_zero_address, |
86 | sizeof(tee_zero_address)) == 0) | |
87 | return -EINVAL; | |
88 | ||
89 | if (info->oif[0]) { | |
90 | if (info->oif[sizeof(info->oif)-1] != '\0') | |
91 | return -EINVAL; | |
92 | ||
93 | priv = kzalloc(sizeof(*priv), GFP_KERNEL); | |
94 | if (priv == NULL) | |
95 | return -ENOMEM; | |
96 | ||
97 | priv->tginfo = info; | |
98 | priv->oif = -1; | |
99 | priv->notifier.notifier_call = tee_netdev_event; | |
100 | info->priv = priv; | |
101 | ||
102 | register_netdevice_notifier(&priv->notifier); | |
103 | } else | |
104 | info->priv = NULL; | |
105 | ||
dcebd315 | 106 | static_key_slow_inc(&xt_tee_enabled); |
22265a5c PM |
107 | return 0; |
108 | } | |
109 | ||
110 | static void tee_tg_destroy(const struct xt_tgdtor_param *par) | |
111 | { | |
112 | struct xt_tee_tginfo *info = par->targinfo; | |
113 | ||
114 | if (info->priv) { | |
115 | unregister_netdevice_notifier(&info->priv->notifier); | |
116 | kfree(info->priv); | |
117 | } | |
dcebd315 | 118 | static_key_slow_dec(&xt_tee_enabled); |
e281b198 JE |
119 | } |
120 | ||
121 | static struct xt_target tee_tg_reg[] __read_mostly = { | |
122 | { | |
123 | .name = "TEE", | |
124 | .revision = 1, | |
125 | .family = NFPROTO_IPV4, | |
126 | .target = tee_tg4, | |
127 | .targetsize = sizeof(struct xt_tee_tginfo), | |
128 | .checkentry = tee_tg_check, | |
22265a5c | 129 | .destroy = tee_tg_destroy, |
e281b198 JE |
130 | .me = THIS_MODULE, |
131 | }, | |
116984a3 | 132 | #if IS_ENABLED(CONFIG_NF_DUP_IPV6) |
e281b198 JE |
133 | { |
134 | .name = "TEE", | |
135 | .revision = 1, | |
136 | .family = NFPROTO_IPV6, | |
137 | .target = tee_tg6, | |
138 | .targetsize = sizeof(struct xt_tee_tginfo), | |
139 | .checkentry = tee_tg_check, | |
22265a5c | 140 | .destroy = tee_tg_destroy, |
e281b198 JE |
141 | .me = THIS_MODULE, |
142 | }, | |
143 | #endif | |
144 | }; | |
145 | ||
146 | static int __init tee_tg_init(void) | |
147 | { | |
148 | return xt_register_targets(tee_tg_reg, ARRAY_SIZE(tee_tg_reg)); | |
149 | } | |
150 | ||
151 | static void __exit tee_tg_exit(void) | |
152 | { | |
153 | xt_unregister_targets(tee_tg_reg, ARRAY_SIZE(tee_tg_reg)); | |
154 | } | |
155 | ||
156 | module_init(tee_tg_init); | |
157 | module_exit(tee_tg_exit); | |
158 | MODULE_AUTHOR("Sebastian Claßen <sebastian.classen@freenet.ag>"); | |
159 | MODULE_AUTHOR("Jan Engelhardt <jengelh@medozas.de>"); | |
160 | MODULE_DESCRIPTION("Xtables: Reroute packet copy"); | |
161 | MODULE_LICENSE("GPL"); | |
162 | MODULE_ALIAS("ipt_TEE"); | |
163 | MODULE_ALIAS("ip6t_TEE"); |