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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#include <net/nexthop.h>
30
31#ifdef CONFIG_MODULES
32
33static const char *lwtunnel_encap_str(enum lwtunnel_encap_types encap_type)
34{
35
36
37
38 switch (encap_type) {
39 case LWTUNNEL_ENCAP_MPLS:
40 return "MPLS";
41 case LWTUNNEL_ENCAP_ILA:
42 return "ILA";
43 case LWTUNNEL_ENCAP_SEG6:
44 return "SEG6";
45 case LWTUNNEL_ENCAP_BPF:
46 return "BPF";
47 case LWTUNNEL_ENCAP_IP6:
48 case LWTUNNEL_ENCAP_IP:
49 case LWTUNNEL_ENCAP_NONE:
50 case __LWTUNNEL_ENCAP_MAX:
51
52 WARN_ON(1);
53 break;
54 }
55 return NULL;
56}
57
58#endif
59
60struct lwtunnel_state *lwtunnel_state_alloc(int encap_len)
61{
62 struct lwtunnel_state *lws;
63
64 lws = kzalloc(sizeof(*lws) + encap_len, GFP_ATOMIC);
65
66 return lws;
67}
68EXPORT_SYMBOL(lwtunnel_state_alloc);
69
70static const struct lwtunnel_encap_ops __rcu *
71 lwtun_encaps[LWTUNNEL_ENCAP_MAX + 1] __read_mostly;
72
73int lwtunnel_encap_add_ops(const struct lwtunnel_encap_ops *ops,
74 unsigned int num)
75{
76 if (num > LWTUNNEL_ENCAP_MAX)
77 return -ERANGE;
78
79 return !cmpxchg((const struct lwtunnel_encap_ops **)
80 &lwtun_encaps[num],
81 NULL, ops) ? 0 : -1;
82}
83EXPORT_SYMBOL(lwtunnel_encap_add_ops);
84
85int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *ops,
86 unsigned int encap_type)
87{
88 int ret;
89
90 if (encap_type == LWTUNNEL_ENCAP_NONE ||
91 encap_type > LWTUNNEL_ENCAP_MAX)
92 return -ERANGE;
93
94 ret = (cmpxchg((const struct lwtunnel_encap_ops **)
95 &lwtun_encaps[encap_type],
96 ops, NULL) == ops) ? 0 : -1;
97
98 synchronize_net();
99
100 return ret;
101}
102EXPORT_SYMBOL(lwtunnel_encap_del_ops);
103
104int lwtunnel_build_state(struct net_device *dev, u16 encap_type,
105 struct nlattr *encap, unsigned int family,
106 const void *cfg, struct lwtunnel_state **lws)
107{
108 const struct lwtunnel_encap_ops *ops;
109 int ret = -EINVAL;
110
111 if (encap_type == LWTUNNEL_ENCAP_NONE ||
112 encap_type > LWTUNNEL_ENCAP_MAX)
113 return ret;
114
115 ret = -EOPNOTSUPP;
116 rcu_read_lock();
117 ops = rcu_dereference(lwtun_encaps[encap_type]);
118 if (likely(ops && ops->build_state && try_module_get(ops->owner))) {
119 ret = ops->build_state(dev, encap, family, cfg, lws);
120 if (ret)
121 module_put(ops->owner);
122 }
123 rcu_read_unlock();
124
125 return ret;
126}
127EXPORT_SYMBOL(lwtunnel_build_state);
128
129int lwtunnel_valid_encap_type(u16 encap_type)
130{
131 const struct lwtunnel_encap_ops *ops;
132 int ret = -EINVAL;
133
134 if (encap_type == LWTUNNEL_ENCAP_NONE ||
135 encap_type > LWTUNNEL_ENCAP_MAX)
136 return ret;
137
138 rcu_read_lock();
139 ops = rcu_dereference(lwtun_encaps[encap_type]);
140 rcu_read_unlock();
141#ifdef CONFIG_MODULES
142 if (!ops) {
143 const char *encap_type_str = lwtunnel_encap_str(encap_type);
144
145 if (encap_type_str) {
146 __rtnl_unlock();
147 request_module("rtnl-lwt-%s", encap_type_str);
148 rtnl_lock();
149
150 rcu_read_lock();
151 ops = rcu_dereference(lwtun_encaps[encap_type]);
152 rcu_read_unlock();
153 }
154 }
155#endif
156 return ops ? 0 : -EOPNOTSUPP;
157}
158EXPORT_SYMBOL(lwtunnel_valid_encap_type);
159
160int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int remaining)
161{
162 struct rtnexthop *rtnh = (struct rtnexthop *)attr;
163 struct nlattr *nla_entype;
164 struct nlattr *attrs;
165 struct nlattr *nla;
166 u16 encap_type;
167 int attrlen;
168
169 while (rtnh_ok(rtnh, remaining)) {
170 attrlen = rtnh_attrlen(rtnh);
171 if (attrlen > 0) {
172 attrs = rtnh_attrs(rtnh);
173 nla = nla_find(attrs, attrlen, RTA_ENCAP);
174 nla_entype = nla_find(attrs, attrlen, RTA_ENCAP_TYPE);
175
176 if (nla_entype) {
177 encap_type = nla_get_u16(nla_entype);
178
179 if (lwtunnel_valid_encap_type(encap_type) != 0)
180 return -EOPNOTSUPP;
181 }
182 }
183 rtnh = rtnh_next(rtnh, &remaining);
184 }
185
186 return 0;
187}
188EXPORT_SYMBOL(lwtunnel_valid_encap_type_attr);
189
190void lwtstate_free(struct lwtunnel_state *lws)
191{
192 const struct lwtunnel_encap_ops *ops = lwtun_encaps[lws->type];
193
194 if (ops->destroy_state) {
195 ops->destroy_state(lws);
196 kfree_rcu(lws, rcu);
197 } else {
198 kfree(lws);
199 }
200 module_put(ops->owner);
201}
202EXPORT_SYMBOL(lwtstate_free);
203
204int lwtunnel_fill_encap(struct sk_buff *skb, struct lwtunnel_state *lwtstate)
205{
206 const struct lwtunnel_encap_ops *ops;
207 struct nlattr *nest;
208 int ret = -EINVAL;
209
210 if (!lwtstate)
211 return 0;
212
213 if (lwtstate->type == LWTUNNEL_ENCAP_NONE ||
214 lwtstate->type > LWTUNNEL_ENCAP_MAX)
215 return 0;
216
217 ret = -EOPNOTSUPP;
218 nest = nla_nest_start(skb, RTA_ENCAP);
219 rcu_read_lock();
220 ops = rcu_dereference(lwtun_encaps[lwtstate->type]);
221 if (likely(ops && ops->fill_encap))
222 ret = ops->fill_encap(skb, lwtstate);
223 rcu_read_unlock();
224
225 if (ret)
226 goto nla_put_failure;
227 nla_nest_end(skb, nest);
228 ret = nla_put_u16(skb, RTA_ENCAP_TYPE, lwtstate->type);
229 if (ret)
230 goto nla_put_failure;
231
232 return 0;
233
234nla_put_failure:
235 nla_nest_cancel(skb, nest);
236
237 return (ret == -EOPNOTSUPP ? 0 : ret);
238}
239EXPORT_SYMBOL(lwtunnel_fill_encap);
240
241int lwtunnel_get_encap_size(struct lwtunnel_state *lwtstate)
242{
243 const struct lwtunnel_encap_ops *ops;
244 int ret = 0;
245
246 if (!lwtstate)
247 return 0;
248
249 if (lwtstate->type == LWTUNNEL_ENCAP_NONE ||
250 lwtstate->type > LWTUNNEL_ENCAP_MAX)
251 return 0;
252
253 rcu_read_lock();
254 ops = rcu_dereference(lwtun_encaps[lwtstate->type]);
255 if (likely(ops && ops->get_encap_size))
256 ret = nla_total_size(ops->get_encap_size(lwtstate));
257 rcu_read_unlock();
258
259 return ret;
260}
261EXPORT_SYMBOL(lwtunnel_get_encap_size);
262
263int lwtunnel_cmp_encap(struct lwtunnel_state *a, struct lwtunnel_state *b)
264{
265 const struct lwtunnel_encap_ops *ops;
266 int ret = 0;
267
268 if (!a && !b)
269 return 0;
270
271 if (!a || !b)
272 return 1;
273
274 if (a->type != b->type)
275 return 1;
276
277 if (a->type == LWTUNNEL_ENCAP_NONE ||
278 a->type > LWTUNNEL_ENCAP_MAX)
279 return 0;
280
281 rcu_read_lock();
282 ops = rcu_dereference(lwtun_encaps[a->type]);
283 if (likely(ops && ops->cmp_encap))
284 ret = ops->cmp_encap(a, b);
285 rcu_read_unlock();
286
287 return ret;
288}
289EXPORT_SYMBOL(lwtunnel_cmp_encap);
290
291int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb)
292{
293 struct dst_entry *dst = skb_dst(skb);
294 const struct lwtunnel_encap_ops *ops;
295 struct lwtunnel_state *lwtstate;
296 int ret = -EINVAL;
297
298 if (!dst)
299 goto drop;
300 lwtstate = dst->lwtstate;
301
302 if (lwtstate->type == LWTUNNEL_ENCAP_NONE ||
303 lwtstate->type > LWTUNNEL_ENCAP_MAX)
304 return 0;
305
306 ret = -EOPNOTSUPP;
307 rcu_read_lock();
308 ops = rcu_dereference(lwtun_encaps[lwtstate->type]);
309 if (likely(ops && ops->output))
310 ret = ops->output(net, sk, skb);
311 rcu_read_unlock();
312
313 if (ret == -EOPNOTSUPP)
314 goto drop;
315
316 return ret;
317
318drop:
319 kfree_skb(skb);
320
321 return ret;
322}
323EXPORT_SYMBOL(lwtunnel_output);
324
325int lwtunnel_xmit(struct sk_buff *skb)
326{
327 struct dst_entry *dst = skb_dst(skb);
328 const struct lwtunnel_encap_ops *ops;
329 struct lwtunnel_state *lwtstate;
330 int ret = -EINVAL;
331
332 if (!dst)
333 goto drop;
334
335 lwtstate = dst->lwtstate;
336
337 if (lwtstate->type == LWTUNNEL_ENCAP_NONE ||
338 lwtstate->type > LWTUNNEL_ENCAP_MAX)
339 return 0;
340
341 ret = -EOPNOTSUPP;
342 rcu_read_lock();
343 ops = rcu_dereference(lwtun_encaps[lwtstate->type]);
344 if (likely(ops && ops->xmit))
345 ret = ops->xmit(skb);
346 rcu_read_unlock();
347
348 if (ret == -EOPNOTSUPP)
349 goto drop;
350
351 return ret;
352
353drop:
354 kfree_skb(skb);
355
356 return ret;
357}
358EXPORT_SYMBOL(lwtunnel_xmit);
359
360int lwtunnel_input(struct sk_buff *skb)
361{
362 struct dst_entry *dst = skb_dst(skb);
363 const struct lwtunnel_encap_ops *ops;
364 struct lwtunnel_state *lwtstate;
365 int ret = -EINVAL;
366
367 if (!dst)
368 goto drop;
369 lwtstate = dst->lwtstate;
370
371 if (lwtstate->type == LWTUNNEL_ENCAP_NONE ||
372 lwtstate->type > LWTUNNEL_ENCAP_MAX)
373 return 0;
374
375 ret = -EOPNOTSUPP;
376 rcu_read_lock();
377 ops = rcu_dereference(lwtun_encaps[lwtstate->type]);
378 if (likely(ops && ops->input))
379 ret = ops->input(skb);
380 rcu_read_unlock();
381
382 if (ret == -EOPNOTSUPP)
383 goto drop;
384
385 return ret;
386
387drop:
388 kfree_skb(skb);
389
390 return ret;
391}
392EXPORT_SYMBOL(lwtunnel_input);
393
