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8
9#define pr_fmt(fmt) "IPv6: " fmt
10
11#include <linux/icmpv6.h>
12#include <linux/init.h>
13#include <linux/module.h>
14#include <linux/mutex.h>
15#include <linux/netdevice.h>
16#include <linux/skbuff.h>
17#include <linux/slab.h>
18#include <net/ipv6.h>
19#include <net/protocol.h>
20#include <net/xfrm.h>
21
22static struct xfrm6_tunnel __rcu *tunnel6_handlers __read_mostly;
23static struct xfrm6_tunnel __rcu *tunnel46_handlers __read_mostly;
24static DEFINE_MUTEX(tunnel6_mutex);
25
26int xfrm6_tunnel_register(struct xfrm6_tunnel *handler, unsigned short family)
27{
28 struct xfrm6_tunnel __rcu **pprev;
29 struct xfrm6_tunnel *t;
30 int ret = -EEXIST;
31 int priority = handler->priority;
32
33 mutex_lock(&tunnel6_mutex);
34
35 for (pprev = (family == AF_INET6) ? &tunnel6_handlers : &tunnel46_handlers;
36 (t = rcu_dereference_protected(*pprev,
37 lockdep_is_held(&tunnel6_mutex))) != NULL;
38 pprev = &t->next) {
39 if (t->priority > priority)
40 break;
41 if (t->priority == priority)
42 goto err;
43 }
44
45 handler->next = *pprev;
46 rcu_assign_pointer(*pprev, handler);
47
48 ret = 0;
49
50err:
51 mutex_unlock(&tunnel6_mutex);
52
53 return ret;
54}
55EXPORT_SYMBOL(xfrm6_tunnel_register);
56
57int xfrm6_tunnel_deregister(struct xfrm6_tunnel *handler, unsigned short family)
58{
59 struct xfrm6_tunnel __rcu **pprev;
60 struct xfrm6_tunnel *t;
61 int ret = -ENOENT;
62
63 mutex_lock(&tunnel6_mutex);
64
65 for (pprev = (family == AF_INET6) ? &tunnel6_handlers : &tunnel46_handlers;
66 (t = rcu_dereference_protected(*pprev,
67 lockdep_is_held(&tunnel6_mutex))) != NULL;
68 pprev = &t->next) {
69 if (t == handler) {
70 *pprev = handler->next;
71 ret = 0;
72 break;
73 }
74 }
75
76 mutex_unlock(&tunnel6_mutex);
77
78 synchronize_net();
79
80 return ret;
81}
82EXPORT_SYMBOL(xfrm6_tunnel_deregister);
83
84#define for_each_tunnel_rcu(head, handler) \
85 for (handler = rcu_dereference(head); \
86 handler != NULL; \
87 handler = rcu_dereference(handler->next)) \
88
89static int tunnel6_rcv(struct sk_buff *skb)
90{
91 struct xfrm6_tunnel *handler;
92
93 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
94 goto drop;
95
96 for_each_tunnel_rcu(tunnel6_handlers, handler)
97 if (!handler->handler(skb))
98 return 0;
99
100 icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
101
102drop:
103 kfree_skb(skb);
104 return 0;
105}
106
107static int tunnel46_rcv(struct sk_buff *skb)
108{
109 struct xfrm6_tunnel *handler;
110
111 if (!pskb_may_pull(skb, sizeof(struct iphdr)))
112 goto drop;
113
114 for_each_tunnel_rcu(tunnel46_handlers, handler)
115 if (!handler->handler(skb))
116 return 0;
117
118 icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
119
120drop:
121 kfree_skb(skb);
122 return 0;
123}
124
125static int tunnel6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
126 u8 type, u8 code, int offset, __be32 info)
127{
128 struct xfrm6_tunnel *handler;
129
130 for_each_tunnel_rcu(tunnel6_handlers, handler)
131 if (!handler->err_handler(skb, opt, type, code, offset, info))
132 return 0;
133
134 return -ENOENT;
135}
136
137static int tunnel46_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
138 u8 type, u8 code, int offset, __be32 info)
139{
140 struct xfrm6_tunnel *handler;
141
142 for_each_tunnel_rcu(tunnel46_handlers, handler)
143 if (!handler->err_handler(skb, opt, type, code, offset, info))
144 return 0;
145
146 return -ENOENT;
147}
148
149static const struct inet6_protocol tunnel6_protocol = {
150 .handler = tunnel6_rcv,
151 .err_handler = tunnel6_err,
152 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
153};
154
155static const struct inet6_protocol tunnel46_protocol = {
156 .handler = tunnel46_rcv,
157 .err_handler = tunnel46_err,
158 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
159};
160
161static int __init tunnel6_init(void)
162{
163 if (inet6_add_protocol(&tunnel6_protocol, IPPROTO_IPV6)) {
164 pr_err("%s: can't add protocol\n", __func__);
165 return -EAGAIN;
166 }
167 if (inet6_add_protocol(&tunnel46_protocol, IPPROTO_IPIP)) {
168 pr_err("%s: can't add protocol\n", __func__);
169 inet6_del_protocol(&tunnel6_protocol, IPPROTO_IPV6);
170 return -EAGAIN;
171 }
172 return 0;
173}
174
175static void __exit tunnel6_fini(void)
176{
177 if (inet6_del_protocol(&tunnel46_protocol, IPPROTO_IPIP))
178 pr_err("%s: can't remove protocol\n", __func__);
179 if (inet6_del_protocol(&tunnel6_protocol, IPPROTO_IPV6))
180 pr_err("%s: can't remove protocol\n", __func__);
181}
182
183module_init(tunnel6_init);
184module_exit(tunnel6_fini);
185MODULE_LICENSE("GPL");
186
