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22#define pr_fmt(fmt) "IPv6: " fmt
23
24#include <linux/icmpv6.h>
25#include <linux/init.h>
26#include <linux/module.h>
27#include <linux/mutex.h>
28#include <linux/netdevice.h>
29#include <linux/skbuff.h>
30#include <linux/slab.h>
31#include <net/ipv6.h>
32#include <net/protocol.h>
33#include <net/xfrm.h>
34
35static struct xfrm6_tunnel __rcu *tunnel6_handlers __read_mostly;
36static struct xfrm6_tunnel __rcu *tunnel46_handlers __read_mostly;
37static DEFINE_MUTEX(tunnel6_mutex);
38
39int xfrm6_tunnel_register(struct xfrm6_tunnel *handler, unsigned short family)
40{
41 struct xfrm6_tunnel __rcu **pprev;
42 struct xfrm6_tunnel *t;
43 int ret = -EEXIST;
44 int priority = handler->priority;
45
46 mutex_lock(&tunnel6_mutex);
47
48 for (pprev = (family == AF_INET6) ? &tunnel6_handlers : &tunnel46_handlers;
49 (t = rcu_dereference_protected(*pprev,
50 lockdep_is_held(&tunnel6_mutex))) != NULL;
51 pprev = &t->next) {
52 if (t->priority > priority)
53 break;
54 if (t->priority == priority)
55 goto err;
56 }
57
58 handler->next = *pprev;
59 rcu_assign_pointer(*pprev, handler);
60
61 ret = 0;
62
63err:
64 mutex_unlock(&tunnel6_mutex);
65
66 return ret;
67}
68
69EXPORT_SYMBOL(xfrm6_tunnel_register);
70
71int xfrm6_tunnel_deregister(struct xfrm6_tunnel *handler, unsigned short family)
72{
73 struct xfrm6_tunnel __rcu **pprev;
74 struct xfrm6_tunnel *t;
75 int ret = -ENOENT;
76
77 mutex_lock(&tunnel6_mutex);
78
79 for (pprev = (family == AF_INET6) ? &tunnel6_handlers : &tunnel46_handlers;
80 (t = rcu_dereference_protected(*pprev,
81 lockdep_is_held(&tunnel6_mutex))) != NULL;
82 pprev = &t->next) {
83 if (t == handler) {
84 *pprev = handler->next;
85 ret = 0;
86 break;
87 }
88 }
89
90 mutex_unlock(&tunnel6_mutex);
91
92 synchronize_net();
93
94 return ret;
95}
96
97EXPORT_SYMBOL(xfrm6_tunnel_deregister);
98
99#define for_each_tunnel_rcu(head, handler) \
100 for (handler = rcu_dereference(head); \
101 handler != NULL; \
102 handler = rcu_dereference(handler->next)) \
103
104static int tunnel6_rcv(struct sk_buff *skb)
105{
106 struct xfrm6_tunnel *handler;
107
108 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
109 goto drop;
110
111 for_each_tunnel_rcu(tunnel6_handlers, handler)
112 if (!handler->handler(skb))
113 return 0;
114
115 icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
116
117drop:
118 kfree_skb(skb);
119 return 0;
120}
121
122static int tunnel46_rcv(struct sk_buff *skb)
123{
124 struct xfrm6_tunnel *handler;
125
126 if (!pskb_may_pull(skb, sizeof(struct iphdr)))
127 goto drop;
128
129 for_each_tunnel_rcu(tunnel46_handlers, handler)
130 if (!handler->handler(skb))
131 return 0;
132
133 icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
134
135drop:
136 kfree_skb(skb);
137 return 0;
138}
139
140static void tunnel6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
141 u8 type, u8 code, int offset, __be32 info)
142{
143 struct xfrm6_tunnel *handler;
144
145 for_each_tunnel_rcu(tunnel6_handlers, handler)
146 if (!handler->err_handler(skb, opt, type, code, offset, info))
147 break;
148}
149
150static const struct inet6_protocol tunnel6_protocol = {
151 .handler = tunnel6_rcv,
152 .err_handler = tunnel6_err,
153 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
154};
155
156static const struct inet6_protocol tunnel46_protocol = {
157 .handler = tunnel46_rcv,
158 .err_handler = tunnel6_err,
159 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
160};
161
162static int __init tunnel6_init(void)
163{
164 if (inet6_add_protocol(&tunnel6_protocol, IPPROTO_IPV6)) {
165 pr_err("%s: can't add protocol\n", __func__);
166 return -EAGAIN;
167 }
168 if (inet6_add_protocol(&tunnel46_protocol, IPPROTO_IPIP)) {
169 pr_err("%s: can't add protocol\n", __func__);
170 inet6_del_protocol(&tunnel6_protocol, IPPROTO_IPV6);
171 return -EAGAIN;
172 }
173 return 0;
174}
175
176static void __exit tunnel6_fini(void)
177{
178 if (inet6_del_protocol(&tunnel46_protocol, IPPROTO_IPIP))
179 pr_err("%s: can't remove protocol\n", __func__);
180 if (inet6_del_protocol(&tunnel6_protocol, IPPROTO_IPV6))
181 pr_err("%s: can't remove protocol\n", __func__);
182}
183
184module_init(tunnel6_init);
185module_exit(tunnel6_fini);
186MODULE_LICENSE("GPL");
187
