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20
21#define pr_fmt(fmt) "IPv6: " fmt
22
23#include <linux/icmpv6.h>
24#include <linux/init.h>
25#include <linux/module.h>
26#include <linux/mutex.h>
27#include <linux/netdevice.h>
28#include <linux/skbuff.h>
29#include <linux/slab.h>
30#include <net/ipv6.h>
31#include <net/protocol.h>
32#include <net/xfrm.h>
33
34static struct xfrm6_tunnel __rcu *tunnel6_handlers __read_mostly;
35static struct xfrm6_tunnel __rcu *tunnel46_handlers __read_mostly;
36static DEFINE_MUTEX(tunnel6_mutex);
37
38int xfrm6_tunnel_register(struct xfrm6_tunnel *handler, unsigned short family)
39{
40 struct xfrm6_tunnel __rcu **pprev;
41 struct xfrm6_tunnel *t;
42 int ret = -EEXIST;
43 int priority = handler->priority;
44
45 mutex_lock(&tunnel6_mutex);
46
47 for (pprev = (family == AF_INET6) ? &tunnel6_handlers : &tunnel46_handlers;
48 (t = rcu_dereference_protected(*pprev,
49 lockdep_is_held(&tunnel6_mutex))) != NULL;
50 pprev = &t->next) {
51 if (t->priority > priority)
52 break;
53 if (t->priority == priority)
54 goto err;
55 }
56
57 handler->next = *pprev;
58 rcu_assign_pointer(*pprev, handler);
59
60 ret = 0;
61
62err:
63 mutex_unlock(&tunnel6_mutex);
64
65 return ret;
66}
67EXPORT_SYMBOL(xfrm6_tunnel_register);
68
69int xfrm6_tunnel_deregister(struct xfrm6_tunnel *handler, unsigned short family)
70{
71 struct xfrm6_tunnel __rcu **pprev;
72 struct xfrm6_tunnel *t;
73 int ret = -ENOENT;
74
75 mutex_lock(&tunnel6_mutex);
76
77 for (pprev = (family == AF_INET6) ? &tunnel6_handlers : &tunnel46_handlers;
78 (t = rcu_dereference_protected(*pprev,
79 lockdep_is_held(&tunnel6_mutex))) != NULL;
80 pprev = &t->next) {
81 if (t == handler) {
82 *pprev = handler->next;
83 ret = 0;
84 break;
85 }
86 }
87
88 mutex_unlock(&tunnel6_mutex);
89
90 synchronize_net();
91
92 return ret;
93}
94EXPORT_SYMBOL(xfrm6_tunnel_deregister);
95
96#define for_each_tunnel_rcu(head, handler) \
97 for (handler = rcu_dereference(head); \
98 handler != NULL; \
99 handler = rcu_dereference(handler->next)) \
100
101static int tunnel6_rcv(struct sk_buff *skb)
102{
103 struct xfrm6_tunnel *handler;
104
105 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
106 goto drop;
107
108 for_each_tunnel_rcu(tunnel6_handlers, handler)
109 if (!handler->handler(skb))
110 return 0;
111
112 icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
113
114drop:
115 kfree_skb(skb);
116 return 0;
117}
118
119static int tunnel46_rcv(struct sk_buff *skb)
120{
121 struct xfrm6_tunnel *handler;
122
123 if (!pskb_may_pull(skb, sizeof(struct iphdr)))
124 goto drop;
125
126 for_each_tunnel_rcu(tunnel46_handlers, handler)
127 if (!handler->handler(skb))
128 return 0;
129
130 icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
131
132drop:
133 kfree_skb(skb);
134 return 0;
135}
136
137static void tunnel6_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(tunnel6_handlers, handler)
143 if (!handler->err_handler(skb, opt, type, code, offset, info))
144 break;
145}
146
147static void tunnel46_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
148 u8 type, u8 code, int offset, __be32 info)
149{
150 struct xfrm6_tunnel *handler;
151
152 for_each_tunnel_rcu(tunnel46_handlers, handler)
153 if (!handler->err_handler(skb, opt, type, code, offset, info))
154 break;
155}
156
157static const struct inet6_protocol tunnel6_protocol = {
158 .handler = tunnel6_rcv,
159 .err_handler = tunnel6_err,
160 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
161};
162
163static const struct inet6_protocol tunnel46_protocol = {
164 .handler = tunnel46_rcv,
165 .err_handler = tunnel46_err,
166 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
167};
168
169static int __init tunnel6_init(void)
170{
171 if (inet6_add_protocol(&tunnel6_protocol, IPPROTO_IPV6)) {
172 pr_err("%s: can't add protocol\n", __func__);
173 return -EAGAIN;
174 }
175 if (inet6_add_protocol(&tunnel46_protocol, IPPROTO_IPIP)) {
176 pr_err("%s: can't add protocol\n", __func__);
177 inet6_del_protocol(&tunnel6_protocol, IPPROTO_IPV6);
178 return -EAGAIN;
179 }
180 return 0;
181}
182
183static void __exit tunnel6_fini(void)
184{
185 if (inet6_del_protocol(&tunnel46_protocol, IPPROTO_IPIP))
186 pr_err("%s: can't remove protocol\n", __func__);
187 if (inet6_del_protocol(&tunnel6_protocol, IPPROTO_IPV6))
188 pr_err("%s: can't remove protocol\n", __func__);
189}
190
191module_init(tunnel6_init);
192module_exit(tunnel6_fini);
193MODULE_LICENSE("GPL");
194
