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13#include <linux/capability.h>
14#include <linux/module.h>
15#include <linux/types.h>
16#include <linux/kernel.h>
17#include <linux/slab.h>
18#include <linux/uaccess.h>
19#include <linux/skbuff.h>
20#include <linux/netdevice.h>
21#include <linux/lwtunnel.h>
22#include <linux/in.h>
23#include <linux/init.h>
24#include <linux/err.h>
25
26#include <net/lwtunnel.h>
27#include <net/rtnetlink.h>
28#include <net/ip6_fib.h>
29
30#ifdef CONFIG_MODULES
31
32static const char *lwtunnel_encap_str(enum lwtunnel_encap_types encap_type)
33{
34
35
36
37 switch (encap_type) {
38 case LWTUNNEL_ENCAP_MPLS:
39 return "MPLS";
40 case LWTUNNEL_ENCAP_ILA:
41 return "ILA";
42 case LWTUNNEL_ENCAP_IP6:
43 case LWTUNNEL_ENCAP_IP:
44 case LWTUNNEL_ENCAP_NONE:
45 case __LWTUNNEL_ENCAP_MAX:
46
47 WARN_ON(1);
48 break;
49 }
50 return NULL;
51}
52
53#endif
54
55struct lwtunnel_state *lwtunnel_state_alloc(int encap_len)
56{
57 struct lwtunnel_state *lws;
58
59 lws = kzalloc(sizeof(*lws) + encap_len, GFP_ATOMIC);
60
61 return lws;
62}
63EXPORT_SYMBOL(lwtunnel_state_alloc);
64
65static const struct lwtunnel_encap_ops __rcu *
66 lwtun_encaps[LWTUNNEL_ENCAP_MAX + 1] __read_mostly;
67
68int lwtunnel_encap_add_ops(const struct lwtunnel_encap_ops *ops,
69 unsigned int num)
70{
71 if (num > LWTUNNEL_ENCAP_MAX)
72 return -ERANGE;
73
74 return !cmpxchg((const struct lwtunnel_encap_ops **)
75 &lwtun_encaps[num],
76 NULL, ops) ? 0 : -1;
77}
78EXPORT_SYMBOL(lwtunnel_encap_add_ops);
79
80int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *ops,
81 unsigned int encap_type)
82{
83 int ret;
84
85 if (encap_type == LWTUNNEL_ENCAP_NONE ||
86 encap_type > LWTUNNEL_ENCAP_MAX)
87 return -ERANGE;
88
89 ret = (cmpxchg((const struct lwtunnel_encap_ops **)
90 &lwtun_encaps[encap_type],
91 ops, NULL) == ops) ? 0 : -1;
92
93 synchronize_net();
94
95 return ret;
96}
97EXPORT_SYMBOL(lwtunnel_encap_del_ops);
98
99int lwtunnel_build_state(struct net_device *dev, u16 encap_type,
100 struct nlattr *encap, unsigned int family,
101 const void *cfg, struct lwtunnel_state **lws)
102{
103 const struct lwtunnel_encap_ops *ops;
104 int ret = -EINVAL;
105
106 if (encap_type == LWTUNNEL_ENCAP_NONE ||
107 encap_type > LWTUNNEL_ENCAP_MAX)
108 return ret;
109
110 ret = -EOPNOTSUPP;
111 rcu_read_lock();
112 ops = rcu_dereference(lwtun_encaps[encap_type]);
113#ifdef CONFIG_MODULES
114 if (!ops) {
115 const char *encap_type_str = lwtunnel_encap_str(encap_type);
116
117 if (encap_type_str) {
118 rcu_read_unlock();
119 request_module("rtnl-lwt-%s", encap_type_str);
120 rcu_read_lock();
121 ops = rcu_dereference(lwtun_encaps[encap_type]);
122 }
123 }
124#endif
125 if (likely(ops && ops->build_state))
126 ret = ops->build_state(dev, encap, family, cfg, lws);
127 rcu_read_unlock();
128
129 return ret;
130}
131EXPORT_SYMBOL(lwtunnel_build_state);
132
133int lwtunnel_fill_encap(struct sk_buff *skb, struct lwtunnel_state *lwtstate)
134{
135 const struct lwtunnel_encap_ops *ops;
136 struct nlattr *nest;
137 int ret = -EINVAL;
138
139 if (!lwtstate)
140 return 0;
141
142 if (lwtstate->type == LWTUNNEL_ENCAP_NONE ||
143 lwtstate->type > LWTUNNEL_ENCAP_MAX)
144 return 0;
145
146 ret = -EOPNOTSUPP;
147 nest = nla_nest_start(skb, RTA_ENCAP);
148 rcu_read_lock();
149 ops = rcu_dereference(lwtun_encaps[lwtstate->type]);
150 if (likely(ops && ops->fill_encap))
151 ret = ops->fill_encap(skb, lwtstate);
152 rcu_read_unlock();
153
154 if (ret)
155 goto nla_put_failure;
156 nla_nest_end(skb, nest);
157 ret = nla_put_u16(skb, RTA_ENCAP_TYPE, lwtstate->type);
158 if (ret)
159 goto nla_put_failure;
160
161 return 0;
162
163nla_put_failure:
164 nla_nest_cancel(skb, nest);
165
166 return (ret == -EOPNOTSUPP ? 0 : ret);
167}
168EXPORT_SYMBOL(lwtunnel_fill_encap);
169
170int lwtunnel_get_encap_size(struct lwtunnel_state *lwtstate)
171{
172 const struct lwtunnel_encap_ops *ops;
173 int ret = 0;
174
175 if (!lwtstate)
176 return 0;
177
178 if (lwtstate->type == LWTUNNEL_ENCAP_NONE ||
179 lwtstate->type > LWTUNNEL_ENCAP_MAX)
180 return 0;
181
182 rcu_read_lock();
183 ops = rcu_dereference(lwtun_encaps[lwtstate->type]);
184 if (likely(ops && ops->get_encap_size))
185 ret = nla_total_size(ops->get_encap_size(lwtstate));
186 rcu_read_unlock();
187
188 return ret;
189}
190EXPORT_SYMBOL(lwtunnel_get_encap_size);
191
192int lwtunnel_cmp_encap(struct lwtunnel_state *a, struct lwtunnel_state *b)
193{
194 const struct lwtunnel_encap_ops *ops;
195 int ret = 0;
196
197 if (!a && !b)
198 return 0;
199
200 if (!a || !b)
201 return 1;
202
203 if (a->type != b->type)
204 return 1;
205
206 if (a->type == LWTUNNEL_ENCAP_NONE ||
207 a->type > LWTUNNEL_ENCAP_MAX)
208 return 0;
209
210 rcu_read_lock();
211 ops = rcu_dereference(lwtun_encaps[a->type]);
212 if (likely(ops && ops->cmp_encap))
213 ret = ops->cmp_encap(a, b);
214 rcu_read_unlock();
215
216 return ret;
217}
218EXPORT_SYMBOL(lwtunnel_cmp_encap);
219
220int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb)
221{
222 struct dst_entry *dst = skb_dst(skb);
223 const struct lwtunnel_encap_ops *ops;
224 struct lwtunnel_state *lwtstate;
225 int ret = -EINVAL;
226
227 if (!dst)
228 goto drop;
229 lwtstate = dst->lwtstate;
230
231 if (lwtstate->type == LWTUNNEL_ENCAP_NONE ||
232 lwtstate->type > LWTUNNEL_ENCAP_MAX)
233 return 0;
234
235 ret = -EOPNOTSUPP;
236 rcu_read_lock();
237 ops = rcu_dereference(lwtun_encaps[lwtstate->type]);
238 if (likely(ops && ops->output))
239 ret = ops->output(net, sk, skb);
240 rcu_read_unlock();
241
242 if (ret == -EOPNOTSUPP)
243 goto drop;
244
245 return ret;
246
247drop:
248 kfree_skb(skb);
249
250 return ret;
251}
252EXPORT_SYMBOL(lwtunnel_output);
253
254int lwtunnel_input(struct sk_buff *skb)
255{
256 struct dst_entry *dst = skb_dst(skb);
257 const struct lwtunnel_encap_ops *ops;
258 struct lwtunnel_state *lwtstate;
259 int ret = -EINVAL;
260
261 if (!dst)
262 goto drop;
263 lwtstate = dst->lwtstate;
264
265 if (lwtstate->type == LWTUNNEL_ENCAP_NONE ||
266 lwtstate->type > LWTUNNEL_ENCAP_MAX)
267 return 0;
268
269 ret = -EOPNOTSUPP;
270 rcu_read_lock();
271 ops = rcu_dereference(lwtun_encaps[lwtstate->type]);
272 if (likely(ops && ops->input))
273 ret = ops->input(skb);
274 rcu_read_unlock();
275
276 if (ret == -EOPNOTSUPP)
277 goto drop;
278
279 return ret;
280
281drop:
282 kfree_skb(skb);
283
284 return ret;
285}
286EXPORT_SYMBOL(lwtunnel_input);
287
