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8#include <linux/capability.h>
9#include <linux/module.h>
10#include <linux/types.h>
11#include <linux/kernel.h>
12#include <linux/slab.h>
13#include <linux/uaccess.h>
14#include <linux/skbuff.h>
15#include <linux/netdevice.h>
16#include <linux/lwtunnel.h>
17#include <linux/in.h>
18#include <linux/init.h>
19#include <linux/err.h>
20
21#include <net/lwtunnel.h>
22#include <net/rtnetlink.h>
23#include <net/ip6_fib.h>
24#include <net/rtnh.h>
25
26#ifdef CONFIG_MODULES
27
28static const char *lwtunnel_encap_str(enum lwtunnel_encap_types encap_type)
29{
30
31
32
33 switch (encap_type) {
34 case LWTUNNEL_ENCAP_MPLS:
35 return "MPLS";
36 case LWTUNNEL_ENCAP_ILA:
37 return "ILA";
38 case LWTUNNEL_ENCAP_SEG6:
39 return "SEG6";
40 case LWTUNNEL_ENCAP_BPF:
41 return "BPF";
42 case LWTUNNEL_ENCAP_SEG6_LOCAL:
43 return "SEG6LOCAL";
44 case LWTUNNEL_ENCAP_IP6:
45 case LWTUNNEL_ENCAP_IP:
46 case LWTUNNEL_ENCAP_NONE:
47 case __LWTUNNEL_ENCAP_MAX:
48
49 WARN_ON(1);
50 break;
51 }
52 return NULL;
53}
54
55#endif
56
57struct lwtunnel_state *lwtunnel_state_alloc(int encap_len)
58{
59 struct lwtunnel_state *lws;
60
61 lws = kzalloc(sizeof(*lws) + encap_len, GFP_ATOMIC);
62
63 return lws;
64}
65EXPORT_SYMBOL_GPL(lwtunnel_state_alloc);
66
67static const struct lwtunnel_encap_ops __rcu *
68 lwtun_encaps[LWTUNNEL_ENCAP_MAX + 1] __read_mostly;
69
70int lwtunnel_encap_add_ops(const struct lwtunnel_encap_ops *ops,
71 unsigned int num)
72{
73 if (num > LWTUNNEL_ENCAP_MAX)
74 return -ERANGE;
75
76 return !cmpxchg((const struct lwtunnel_encap_ops **)
77 &lwtun_encaps[num],
78 NULL, ops) ? 0 : -1;
79}
80EXPORT_SYMBOL_GPL(lwtunnel_encap_add_ops);
81
82int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *ops,
83 unsigned int encap_type)
84{
85 int ret;
86
87 if (encap_type == LWTUNNEL_ENCAP_NONE ||
88 encap_type > LWTUNNEL_ENCAP_MAX)
89 return -ERANGE;
90
91 ret = (cmpxchg((const struct lwtunnel_encap_ops **)
92 &lwtun_encaps[encap_type],
93 ops, NULL) == ops) ? 0 : -1;
94
95 synchronize_net();
96
97 return ret;
98}
99EXPORT_SYMBOL_GPL(lwtunnel_encap_del_ops);
100
101int lwtunnel_build_state(u16 encap_type,
102 struct nlattr *encap, unsigned int family,
103 const void *cfg, struct lwtunnel_state **lws,
104 struct netlink_ext_ack *extack)
105{
106 const struct lwtunnel_encap_ops *ops;
107 bool found = false;
108 int ret = -EINVAL;
109
110 if (encap_type == LWTUNNEL_ENCAP_NONE ||
111 encap_type > LWTUNNEL_ENCAP_MAX) {
112 NL_SET_ERR_MSG_ATTR(extack, encap,
113 "Unknown LWT encapsulation type");
114 return ret;
115 }
116
117 ret = -EOPNOTSUPP;
118 rcu_read_lock();
119 ops = rcu_dereference(lwtun_encaps[encap_type]);
120 if (likely(ops && ops->build_state && try_module_get(ops->owner)))
121 found = true;
122 rcu_read_unlock();
123
124 if (found) {
125 ret = ops->build_state(encap, family, cfg, lws, extack);
126 if (ret)
127 module_put(ops->owner);
128 } else {
129
130
131
132 NL_SET_ERR_MSG_ATTR(extack, encap,
133 "LWT encapsulation type not supported");
134 }
135
136 return ret;
137}
138EXPORT_SYMBOL_GPL(lwtunnel_build_state);
139
140int lwtunnel_valid_encap_type(u16 encap_type, struct netlink_ext_ack *extack)
141{
142 const struct lwtunnel_encap_ops *ops;
143 int ret = -EINVAL;
144
145 if (encap_type == LWTUNNEL_ENCAP_NONE ||
146 encap_type > LWTUNNEL_ENCAP_MAX) {
147 NL_SET_ERR_MSG(extack, "Unknown lwt encapsulation type");
148 return ret;
149 }
150
151 rcu_read_lock();
152 ops = rcu_dereference(lwtun_encaps[encap_type]);
153 rcu_read_unlock();
154#ifdef CONFIG_MODULES
155 if (!ops) {
156 const char *encap_type_str = lwtunnel_encap_str(encap_type);
157
158 if (encap_type_str) {
159 __rtnl_unlock();
160 request_module("rtnl-lwt-%s", encap_type_str);
161 rtnl_lock();
162
163 rcu_read_lock();
164 ops = rcu_dereference(lwtun_encaps[encap_type]);
165 rcu_read_unlock();
166 }
167 }
168#endif
169 ret = ops ? 0 : -EOPNOTSUPP;
170 if (ret < 0)
171 NL_SET_ERR_MSG(extack, "lwt encapsulation type not supported");
172
173 return ret;
174}
175EXPORT_SYMBOL_GPL(lwtunnel_valid_encap_type);
176
177int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int remaining,
178 struct netlink_ext_ack *extack)
179{
180 struct rtnexthop *rtnh = (struct rtnexthop *)attr;
181 struct nlattr *nla_entype;
182 struct nlattr *attrs;
183 u16 encap_type;
184 int attrlen;
185
186 while (rtnh_ok(rtnh, remaining)) {
187 attrlen = rtnh_attrlen(rtnh);
188 if (attrlen > 0) {
189 attrs = rtnh_attrs(rtnh);
190 nla_entype = nla_find(attrs, attrlen, RTA_ENCAP_TYPE);
191
192 if (nla_entype) {
193 encap_type = nla_get_u16(nla_entype);
194
195 if (lwtunnel_valid_encap_type(encap_type,
196 extack) != 0)
197 return -EOPNOTSUPP;
198 }
199 }
200 rtnh = rtnh_next(rtnh, &remaining);
201 }
202
203 return 0;
204}
205EXPORT_SYMBOL_GPL(lwtunnel_valid_encap_type_attr);
206
207void lwtstate_free(struct lwtunnel_state *lws)
208{
209 const struct lwtunnel_encap_ops *ops = lwtun_encaps[lws->type];
210
211 if (ops->destroy_state) {
212 ops->destroy_state(lws);
213 kfree_rcu(lws, rcu);
214 } else {
215 kfree(lws);
216 }
217 module_put(ops->owner);
218}
219EXPORT_SYMBOL_GPL(lwtstate_free);
220
221int lwtunnel_fill_encap(struct sk_buff *skb, struct lwtunnel_state *lwtstate,
222 int encap_attr, int encap_type_attr)
223{
224 const struct lwtunnel_encap_ops *ops;
225 struct nlattr *nest;
226 int ret;
227
228 if (!lwtstate)
229 return 0;
230
231 if (lwtstate->type == LWTUNNEL_ENCAP_NONE ||
232 lwtstate->type > LWTUNNEL_ENCAP_MAX)
233 return 0;
234
235 nest = nla_nest_start_noflag(skb, encap_attr);
236 if (!nest)
237 return -EMSGSIZE;
238
239 ret = -EOPNOTSUPP;
240 rcu_read_lock();
241 ops = rcu_dereference(lwtun_encaps[lwtstate->type]);
242 if (likely(ops && ops->fill_encap))
243 ret = ops->fill_encap(skb, lwtstate);
244 rcu_read_unlock();
245
246 if (ret)
247 goto nla_put_failure;
248 nla_nest_end(skb, nest);
249 ret = nla_put_u16(skb, encap_type_attr, lwtstate->type);
250 if (ret)
251 goto nla_put_failure;
252
253 return 0;
254
255nla_put_failure:
256 nla_nest_cancel(skb, nest);
257
258 return (ret == -EOPNOTSUPP ? 0 : ret);
259}
260EXPORT_SYMBOL_GPL(lwtunnel_fill_encap);
261
262int lwtunnel_get_encap_size(struct lwtunnel_state *lwtstate)
263{
264 const struct lwtunnel_encap_ops *ops;
265 int ret = 0;
266
267 if (!lwtstate)
268 return 0;
269
270 if (lwtstate->type == LWTUNNEL_ENCAP_NONE ||
271 lwtstate->type > LWTUNNEL_ENCAP_MAX)
272 return 0;
273
274 rcu_read_lock();
275 ops = rcu_dereference(lwtun_encaps[lwtstate->type]);
276 if (likely(ops && ops->get_encap_size))
277 ret = nla_total_size(ops->get_encap_size(lwtstate));
278 rcu_read_unlock();
279
280 return ret;
281}
282EXPORT_SYMBOL_GPL(lwtunnel_get_encap_size);
283
284int lwtunnel_cmp_encap(struct lwtunnel_state *a, struct lwtunnel_state *b)
285{
286 const struct lwtunnel_encap_ops *ops;
287 int ret = 0;
288
289 if (!a && !b)
290 return 0;
291
292 if (!a || !b)
293 return 1;
294
295 if (a->type != b->type)
296 return 1;
297
298 if (a->type == LWTUNNEL_ENCAP_NONE ||
299 a->type > LWTUNNEL_ENCAP_MAX)
300 return 0;
301
302 rcu_read_lock();
303 ops = rcu_dereference(lwtun_encaps[a->type]);
304 if (likely(ops && ops->cmp_encap))
305 ret = ops->cmp_encap(a, b);
306 rcu_read_unlock();
307
308 return ret;
309}
310EXPORT_SYMBOL_GPL(lwtunnel_cmp_encap);
311
312int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb)
313{
314 struct dst_entry *dst = skb_dst(skb);
315 const struct lwtunnel_encap_ops *ops;
316 struct lwtunnel_state *lwtstate;
317 int ret = -EINVAL;
318
319 if (!dst)
320 goto drop;
321 lwtstate = dst->lwtstate;
322
323 if (lwtstate->type == LWTUNNEL_ENCAP_NONE ||
324 lwtstate->type > LWTUNNEL_ENCAP_MAX)
325 return 0;
326
327 ret = -EOPNOTSUPP;
328 rcu_read_lock();
329 ops = rcu_dereference(lwtun_encaps[lwtstate->type]);
330 if (likely(ops && ops->output))
331 ret = ops->output(net, sk, skb);
332 rcu_read_unlock();
333
334 if (ret == -EOPNOTSUPP)
335 goto drop;
336
337 return ret;
338
339drop:
340 kfree_skb(skb);
341
342 return ret;
343}
344EXPORT_SYMBOL_GPL(lwtunnel_output);
345
346int lwtunnel_xmit(struct sk_buff *skb)
347{
348 struct dst_entry *dst = skb_dst(skb);
349 const struct lwtunnel_encap_ops *ops;
350 struct lwtunnel_state *lwtstate;
351 int ret = -EINVAL;
352
353 if (!dst)
354 goto drop;
355
356 lwtstate = dst->lwtstate;
357
358 if (lwtstate->type == LWTUNNEL_ENCAP_NONE ||
359 lwtstate->type > LWTUNNEL_ENCAP_MAX)
360 return 0;
361
362 ret = -EOPNOTSUPP;
363 rcu_read_lock();
364 ops = rcu_dereference(lwtun_encaps[lwtstate->type]);
365 if (likely(ops && ops->xmit))
366 ret = ops->xmit(skb);
367 rcu_read_unlock();
368
369 if (ret == -EOPNOTSUPP)
370 goto drop;
371
372 return ret;
373
374drop:
375 kfree_skb(skb);
376
377 return ret;
378}
379EXPORT_SYMBOL_GPL(lwtunnel_xmit);
380
381int lwtunnel_input(struct sk_buff *skb)
382{
383 struct dst_entry *dst = skb_dst(skb);
384 const struct lwtunnel_encap_ops *ops;
385 struct lwtunnel_state *lwtstate;
386 int ret = -EINVAL;
387
388 if (!dst)
389 goto drop;
390 lwtstate = dst->lwtstate;
391
392 if (lwtstate->type == LWTUNNEL_ENCAP_NONE ||
393 lwtstate->type > LWTUNNEL_ENCAP_MAX)
394 return 0;
395
396 ret = -EOPNOTSUPP;
397 rcu_read_lock();
398 ops = rcu_dereference(lwtun_encaps[lwtstate->type]);
399 if (likely(ops && ops->input))
400 ret = ops->input(skb);
401 rcu_read_unlock();
402
403 if (ret == -EOPNOTSUPP)
404 goto drop;
405
406 return ret;
407
408drop:
409 kfree_skb(skb);
410
411 return ret;
412}
413EXPORT_SYMBOL_GPL(lwtunnel_input);
414
