Commit | Line | Data |
---|---|---|
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; | |
45efccdb | 34 | int oif = info->priv ? info->priv->oif : 0; |
e281b198 | 35 | |
d9c7dbc1 | 36 | nf_dup_ipv4(par->net, skb, par->hooknum, &info->gw.in, oif); |
e281b198 | 37 | |
e281b198 JE |
38 | return XT_CONTINUE; |
39 | } | |
40 | ||
116984a3 | 41 | #if IS_ENABLED(CONFIG_NF_DUP_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 | |
d9c7dbc1 | 48 | nf_dup_ipv6(par->net, skb, par->hooknum, &info->gw.in6, oif); |
e281b198 | 49 | |
e281b198 JE |
50 | return XT_CONTINUE; |
51 | } | |
dfd56b8b | 52 | #endif |
e281b198 | 53 | |
22265a5c PM |
54 | static int tee_netdev_event(struct notifier_block *this, unsigned long event, |
55 | void *ptr) | |
56 | { | |
351638e7 | 57 | struct net_device *dev = netdev_notifier_info_to_dev(ptr); |
22265a5c PM |
58 | struct xt_tee_priv *priv; |
59 | ||
60 | priv = container_of(this, struct xt_tee_priv, notifier); | |
61 | switch (event) { | |
62 | case NETDEV_REGISTER: | |
63 | if (!strcmp(dev->name, priv->tginfo->oif)) | |
64 | priv->oif = dev->ifindex; | |
65 | break; | |
66 | case NETDEV_UNREGISTER: | |
67 | if (dev->ifindex == priv->oif) | |
68 | priv->oif = -1; | |
69 | break; | |
70 | case NETDEV_CHANGENAME: | |
71 | if (!strcmp(dev->name, priv->tginfo->oif)) | |
72 | priv->oif = dev->ifindex; | |
73 | else if (dev->ifindex == priv->oif) | |
74 | priv->oif = -1; | |
75 | break; | |
76 | } | |
77 | ||
78 | return NOTIFY_DONE; | |
79 | } | |
80 | ||
e281b198 JE |
81 | static int tee_tg_check(const struct xt_tgchk_param *par) |
82 | { | |
22265a5c PM |
83 | struct xt_tee_tginfo *info = par->targinfo; |
84 | struct xt_tee_priv *priv; | |
e281b198 | 85 | |
e281b198 | 86 | /* 0.0.0.0 and :: not allowed */ |
22265a5c PM |
87 | if (memcmp(&info->gw, &tee_zero_address, |
88 | sizeof(tee_zero_address)) == 0) | |
89 | return -EINVAL; | |
90 | ||
91 | if (info->oif[0]) { | |
92 | if (info->oif[sizeof(info->oif)-1] != '\0') | |
93 | return -EINVAL; | |
94 | ||
95 | priv = kzalloc(sizeof(*priv), GFP_KERNEL); | |
96 | if (priv == NULL) | |
97 | return -ENOMEM; | |
98 | ||
99 | priv->tginfo = info; | |
100 | priv->oif = -1; | |
101 | priv->notifier.notifier_call = tee_netdev_event; | |
102 | info->priv = priv; | |
103 | ||
104 | register_netdevice_notifier(&priv->notifier); | |
105 | } else | |
106 | info->priv = NULL; | |
107 | ||
dcebd315 | 108 | static_key_slow_inc(&xt_tee_enabled); |
22265a5c PM |
109 | return 0; |
110 | } | |
111 | ||
112 | static void tee_tg_destroy(const struct xt_tgdtor_param *par) | |
113 | { | |
114 | struct xt_tee_tginfo *info = par->targinfo; | |
115 | ||
116 | if (info->priv) { | |
117 | unregister_netdevice_notifier(&info->priv->notifier); | |
118 | kfree(info->priv); | |
119 | } | |
dcebd315 | 120 | static_key_slow_dec(&xt_tee_enabled); |
e281b198 JE |
121 | } |
122 | ||
123 | static struct xt_target tee_tg_reg[] __read_mostly = { | |
124 | { | |
125 | .name = "TEE", | |
126 | .revision = 1, | |
127 | .family = NFPROTO_IPV4, | |
128 | .target = tee_tg4, | |
129 | .targetsize = sizeof(struct xt_tee_tginfo), | |
130 | .checkentry = tee_tg_check, | |
22265a5c | 131 | .destroy = tee_tg_destroy, |
e281b198 JE |
132 | .me = THIS_MODULE, |
133 | }, | |
116984a3 | 134 | #if IS_ENABLED(CONFIG_NF_DUP_IPV6) |
e281b198 JE |
135 | { |
136 | .name = "TEE", | |
137 | .revision = 1, | |
138 | .family = NFPROTO_IPV6, | |
139 | .target = tee_tg6, | |
140 | .targetsize = sizeof(struct xt_tee_tginfo), | |
141 | .checkentry = tee_tg_check, | |
22265a5c | 142 | .destroy = tee_tg_destroy, |
e281b198 JE |
143 | .me = THIS_MODULE, |
144 | }, | |
145 | #endif | |
146 | }; | |
147 | ||
148 | static int __init tee_tg_init(void) | |
149 | { | |
150 | return xt_register_targets(tee_tg_reg, ARRAY_SIZE(tee_tg_reg)); | |
151 | } | |
152 | ||
153 | static void __exit tee_tg_exit(void) | |
154 | { | |
155 | xt_unregister_targets(tee_tg_reg, ARRAY_SIZE(tee_tg_reg)); | |
156 | } | |
157 | ||
158 | module_init(tee_tg_init); | |
159 | module_exit(tee_tg_exit); | |
160 | MODULE_AUTHOR("Sebastian Claßen <sebastian.classen@freenet.ag>"); | |
161 | MODULE_AUTHOR("Jan Engelhardt <jengelh@medozas.de>"); | |
162 | MODULE_DESCRIPTION("Xtables: Reroute packet copy"); | |
163 | MODULE_LICENSE("GPL"); | |
164 | MODULE_ALIAS("ipt_TEE"); | |
165 | MODULE_ALIAS("ip6t_TEE"); |