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Commit | Line | Data |
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499a2425 RP |
1 | /* |
2 | * lwtunnel Infrastructure for light weight tunnels like mpls | |
3 | * | |
4 | * Authors: Roopa Prabhu, <roopa@cumulusnetworks.com> | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or | |
7 | * modify it under the terms of the GNU General Public License | |
8 | * as published by the Free Software Foundation; either version | |
9 | * 2 of the License, or (at your option) any later version. | |
10 | * | |
11 | */ | |
12 | ||
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> | |
ffce4196 | 28 | #include <net/ip6_fib.h> |
9ed59592 | 29 | #include <net/nexthop.h> |
499a2425 | 30 | |
745041e2 RS |
31 | #ifdef CONFIG_MODULES |
32 | ||
33 | static const char *lwtunnel_encap_str(enum lwtunnel_encap_types encap_type) | |
34 | { | |
35 | /* Only lwt encaps implemented without using an interface for | |
36 | * the encap need to return a string here. | |
37 | */ | |
38 | switch (encap_type) { | |
39 | case LWTUNNEL_ENCAP_MPLS: | |
40 | return "MPLS"; | |
41 | case LWTUNNEL_ENCAP_ILA: | |
42 | return "ILA"; | |
6c8702c6 DL |
43 | case LWTUNNEL_ENCAP_SEG6: |
44 | return "SEG6"; | |
3a0af8fd TG |
45 | case LWTUNNEL_ENCAP_BPF: |
46 | return "BPF"; | |
745041e2 RS |
47 | case LWTUNNEL_ENCAP_IP6: |
48 | case LWTUNNEL_ENCAP_IP: | |
49 | case LWTUNNEL_ENCAP_NONE: | |
50 | case __LWTUNNEL_ENCAP_MAX: | |
51 | /* should not have got here */ | |
52 | WARN_ON(1); | |
53 | break; | |
54 | } | |
55 | return NULL; | |
56 | } | |
57 | ||
58 | #endif /* CONFIG_MODULES */ | |
59 | ||
499a2425 RP |
60 | struct 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 | } | |
68 | EXPORT_SYMBOL(lwtunnel_state_alloc); | |
69 | ||
92a99bf3 | 70 | static const struct lwtunnel_encap_ops __rcu * |
499a2425 RP |
71 | lwtun_encaps[LWTUNNEL_ENCAP_MAX + 1] __read_mostly; |
72 | ||
73 | int 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 | } | |
83 | EXPORT_SYMBOL(lwtunnel_encap_add_ops); | |
84 | ||
85 | int 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 | } | |
102 | EXPORT_SYMBOL(lwtunnel_encap_del_ops); | |
103 | ||
30357d7d | 104 | int lwtunnel_build_state(u16 encap_type, |
127eb7cd | 105 | struct nlattr *encap, unsigned int family, |
9ae28727 DA |
106 | const void *cfg, struct lwtunnel_state **lws, |
107 | struct netlink_ext_ack *extack) | |
499a2425 RP |
108 | { |
109 | const struct lwtunnel_encap_ops *ops; | |
9ae28727 | 110 | bool found = false; |
499a2425 RP |
111 | int ret = -EINVAL; |
112 | ||
113 | if (encap_type == LWTUNNEL_ENCAP_NONE || | |
9ae28727 DA |
114 | encap_type > LWTUNNEL_ENCAP_MAX) { |
115 | NL_SET_ERR_MSG_ATTR(extack, encap, | |
116 | "Unknown LWT encapsulation type"); | |
499a2425 | 117 | return ret; |
9ae28727 | 118 | } |
499a2425 RP |
119 | |
120 | ret = -EOPNOTSUPP; | |
121 | rcu_read_lock(); | |
122 | ops = rcu_dereference(lwtun_encaps[encap_type]); | |
85c81401 | 123 | if (likely(ops && ops->build_state && try_module_get(ops->owner))) { |
9ae28727 DA |
124 | found = true; |
125 | ret = ops->build_state(encap, family, cfg, lws, extack); | |
85c81401 RS |
126 | if (ret) |
127 | module_put(ops->owner); | |
128 | } | |
9ed59592 DA |
129 | rcu_read_unlock(); |
130 | ||
9ae28727 DA |
131 | /* don't rely on -EOPNOTSUPP to detect match as build_state |
132 | * handlers could return it | |
133 | */ | |
134 | if (!found) { | |
135 | NL_SET_ERR_MSG_ATTR(extack, encap, | |
136 | "LWT encapsulation type not supported"); | |
137 | } | |
138 | ||
9ed59592 DA |
139 | return ret; |
140 | } | |
141 | EXPORT_SYMBOL(lwtunnel_build_state); | |
142 | ||
c255bd68 | 143 | int lwtunnel_valid_encap_type(u16 encap_type, struct netlink_ext_ack *extack) |
9ed59592 DA |
144 | { |
145 | const struct lwtunnel_encap_ops *ops; | |
146 | int ret = -EINVAL; | |
147 | ||
148 | if (encap_type == LWTUNNEL_ENCAP_NONE || | |
c255bd68 DA |
149 | encap_type > LWTUNNEL_ENCAP_MAX) { |
150 | NL_SET_ERR_MSG(extack, "Unknown lwt encapsulation type"); | |
9ed59592 | 151 | return ret; |
c255bd68 | 152 | } |
9ed59592 DA |
153 | |
154 | rcu_read_lock(); | |
155 | ops = rcu_dereference(lwtun_encaps[encap_type]); | |
156 | rcu_read_unlock(); | |
745041e2 RS |
157 | #ifdef CONFIG_MODULES |
158 | if (!ops) { | |
159 | const char *encap_type_str = lwtunnel_encap_str(encap_type); | |
160 | ||
161 | if (encap_type_str) { | |
9ed59592 | 162 | __rtnl_unlock(); |
745041e2 | 163 | request_module("rtnl-lwt-%s", encap_type_str); |
9ed59592 DA |
164 | rtnl_lock(); |
165 | ||
745041e2 RS |
166 | rcu_read_lock(); |
167 | ops = rcu_dereference(lwtun_encaps[encap_type]); | |
9ed59592 | 168 | rcu_read_unlock(); |
745041e2 RS |
169 | } |
170 | } | |
171 | #endif | |
c255bd68 DA |
172 | ret = ops ? 0 : -EOPNOTSUPP; |
173 | if (ret < 0) | |
174 | NL_SET_ERR_MSG(extack, "lwt encapsulation type not supported"); | |
175 | ||
176 | return ret; | |
9ed59592 DA |
177 | } |
178 | EXPORT_SYMBOL(lwtunnel_valid_encap_type); | |
499a2425 | 179 | |
c255bd68 DA |
180 | int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int remaining, |
181 | struct netlink_ext_ack *extack) | |
9ed59592 DA |
182 | { |
183 | struct rtnexthop *rtnh = (struct rtnexthop *)attr; | |
184 | struct nlattr *nla_entype; | |
185 | struct nlattr *attrs; | |
9ed59592 DA |
186 | u16 encap_type; |
187 | int attrlen; | |
188 | ||
189 | while (rtnh_ok(rtnh, remaining)) { | |
190 | attrlen = rtnh_attrlen(rtnh); | |
191 | if (attrlen > 0) { | |
192 | attrs = rtnh_attrs(rtnh); | |
9ed59592 DA |
193 | nla_entype = nla_find(attrs, attrlen, RTA_ENCAP_TYPE); |
194 | ||
195 | if (nla_entype) { | |
196 | encap_type = nla_get_u16(nla_entype); | |
197 | ||
c255bd68 DA |
198 | if (lwtunnel_valid_encap_type(encap_type, |
199 | extack) != 0) | |
9ed59592 DA |
200 | return -EOPNOTSUPP; |
201 | } | |
202 | } | |
203 | rtnh = rtnh_next(rtnh, &remaining); | |
204 | } | |
205 | ||
206 | return 0; | |
499a2425 | 207 | } |
9ed59592 | 208 | EXPORT_SYMBOL(lwtunnel_valid_encap_type_attr); |
499a2425 | 209 | |
1104d9ba TH |
210 | void lwtstate_free(struct lwtunnel_state *lws) |
211 | { | |
212 | const struct lwtunnel_encap_ops *ops = lwtun_encaps[lws->type]; | |
213 | ||
214 | if (ops->destroy_state) { | |
215 | ops->destroy_state(lws); | |
216 | kfree_rcu(lws, rcu); | |
217 | } else { | |
218 | kfree(lws); | |
219 | } | |
85c81401 | 220 | module_put(ops->owner); |
1104d9ba TH |
221 | } |
222 | EXPORT_SYMBOL(lwtstate_free); | |
223 | ||
499a2425 RP |
224 | int lwtunnel_fill_encap(struct sk_buff *skb, struct lwtunnel_state *lwtstate) |
225 | { | |
226 | const struct lwtunnel_encap_ops *ops; | |
227 | struct nlattr *nest; | |
39f37095 | 228 | int ret; |
499a2425 RP |
229 | |
230 | if (!lwtstate) | |
231 | return 0; | |
232 | ||
233 | if (lwtstate->type == LWTUNNEL_ENCAP_NONE || | |
234 | lwtstate->type > LWTUNNEL_ENCAP_MAX) | |
235 | return 0; | |
236 | ||
499a2425 | 237 | nest = nla_nest_start(skb, RTA_ENCAP); |
a50fe0ff | 238 | if (!nest) |
39f37095 DC |
239 | return -EMSGSIZE; |
240 | ||
241 | ret = -EOPNOTSUPP; | |
499a2425 RP |
242 | rcu_read_lock(); |
243 | ops = rcu_dereference(lwtun_encaps[lwtstate->type]); | |
244 | if (likely(ops && ops->fill_encap)) | |
245 | ret = ops->fill_encap(skb, lwtstate); | |
246 | rcu_read_unlock(); | |
247 | ||
248 | if (ret) | |
249 | goto nla_put_failure; | |
250 | nla_nest_end(skb, nest); | |
251 | ret = nla_put_u16(skb, RTA_ENCAP_TYPE, lwtstate->type); | |
252 | if (ret) | |
253 | goto nla_put_failure; | |
254 | ||
255 | return 0; | |
256 | ||
257 | nla_put_failure: | |
258 | nla_nest_cancel(skb, nest); | |
259 | ||
260 | return (ret == -EOPNOTSUPP ? 0 : ret); | |
261 | } | |
262 | EXPORT_SYMBOL(lwtunnel_fill_encap); | |
263 | ||
264 | int lwtunnel_get_encap_size(struct lwtunnel_state *lwtstate) | |
265 | { | |
266 | const struct lwtunnel_encap_ops *ops; | |
267 | int ret = 0; | |
268 | ||
269 | if (!lwtstate) | |
270 | return 0; | |
271 | ||
272 | if (lwtstate->type == LWTUNNEL_ENCAP_NONE || | |
273 | lwtstate->type > LWTUNNEL_ENCAP_MAX) | |
274 | return 0; | |
275 | ||
276 | rcu_read_lock(); | |
277 | ops = rcu_dereference(lwtun_encaps[lwtstate->type]); | |
278 | if (likely(ops && ops->get_encap_size)) | |
279 | ret = nla_total_size(ops->get_encap_size(lwtstate)); | |
280 | rcu_read_unlock(); | |
281 | ||
282 | return ret; | |
283 | } | |
284 | EXPORT_SYMBOL(lwtunnel_get_encap_size); | |
285 | ||
286 | int lwtunnel_cmp_encap(struct lwtunnel_state *a, struct lwtunnel_state *b) | |
287 | { | |
288 | const struct lwtunnel_encap_ops *ops; | |
289 | int ret = 0; | |
290 | ||
291 | if (!a && !b) | |
292 | return 0; | |
293 | ||
294 | if (!a || !b) | |
295 | return 1; | |
296 | ||
297 | if (a->type != b->type) | |
298 | return 1; | |
299 | ||
300 | if (a->type == LWTUNNEL_ENCAP_NONE || | |
301 | a->type > LWTUNNEL_ENCAP_MAX) | |
302 | return 0; | |
303 | ||
304 | rcu_read_lock(); | |
305 | ops = rcu_dereference(lwtun_encaps[a->type]); | |
306 | if (likely(ops && ops->cmp_encap)) | |
307 | ret = ops->cmp_encap(a, b); | |
308 | rcu_read_unlock(); | |
309 | ||
310 | return ret; | |
311 | } | |
312 | EXPORT_SYMBOL(lwtunnel_cmp_encap); | |
ffce4196 | 313 | |
ede2059d | 314 | int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb) |
ffce4196 | 315 | { |
61adedf3 | 316 | struct dst_entry *dst = skb_dst(skb); |
ffce4196 | 317 | const struct lwtunnel_encap_ops *ops; |
61adedf3 | 318 | struct lwtunnel_state *lwtstate; |
ffce4196 RP |
319 | int ret = -EINVAL; |
320 | ||
61adedf3 | 321 | if (!dst) |
ffce4196 | 322 | goto drop; |
61adedf3 | 323 | lwtstate = dst->lwtstate; |
ffce4196 RP |
324 | |
325 | if (lwtstate->type == LWTUNNEL_ENCAP_NONE || | |
326 | lwtstate->type > LWTUNNEL_ENCAP_MAX) | |
327 | return 0; | |
328 | ||
329 | ret = -EOPNOTSUPP; | |
330 | rcu_read_lock(); | |
331 | ops = rcu_dereference(lwtun_encaps[lwtstate->type]); | |
332 | if (likely(ops && ops->output)) | |
ede2059d | 333 | ret = ops->output(net, sk, skb); |
ffce4196 RP |
334 | rcu_read_unlock(); |
335 | ||
336 | if (ret == -EOPNOTSUPP) | |
337 | goto drop; | |
338 | ||
339 | return ret; | |
340 | ||
341 | drop: | |
e11f40b9 | 342 | kfree_skb(skb); |
ffce4196 RP |
343 | |
344 | return ret; | |
345 | } | |
ffce4196 | 346 | EXPORT_SYMBOL(lwtunnel_output); |
25368623 | 347 | |
14972cbd RP |
348 | int lwtunnel_xmit(struct sk_buff *skb) |
349 | { | |
350 | struct dst_entry *dst = skb_dst(skb); | |
351 | const struct lwtunnel_encap_ops *ops; | |
352 | struct lwtunnel_state *lwtstate; | |
353 | int ret = -EINVAL; | |
354 | ||
355 | if (!dst) | |
356 | goto drop; | |
357 | ||
358 | lwtstate = dst->lwtstate; | |
359 | ||
360 | if (lwtstate->type == LWTUNNEL_ENCAP_NONE || | |
361 | lwtstate->type > LWTUNNEL_ENCAP_MAX) | |
362 | return 0; | |
363 | ||
364 | ret = -EOPNOTSUPP; | |
365 | rcu_read_lock(); | |
366 | ops = rcu_dereference(lwtun_encaps[lwtstate->type]); | |
367 | if (likely(ops && ops->xmit)) | |
368 | ret = ops->xmit(skb); | |
369 | rcu_read_unlock(); | |
370 | ||
371 | if (ret == -EOPNOTSUPP) | |
372 | goto drop; | |
373 | ||
374 | return ret; | |
375 | ||
376 | drop: | |
377 | kfree_skb(skb); | |
378 | ||
379 | return ret; | |
380 | } | |
381 | EXPORT_SYMBOL(lwtunnel_xmit); | |
382 | ||
61adedf3 | 383 | int lwtunnel_input(struct sk_buff *skb) |
25368623 | 384 | { |
61adedf3 | 385 | struct dst_entry *dst = skb_dst(skb); |
25368623 | 386 | const struct lwtunnel_encap_ops *ops; |
61adedf3 | 387 | struct lwtunnel_state *lwtstate; |
25368623 TH |
388 | int ret = -EINVAL; |
389 | ||
61adedf3 | 390 | if (!dst) |
25368623 | 391 | goto drop; |
61adedf3 | 392 | lwtstate = dst->lwtstate; |
25368623 TH |
393 | |
394 | if (lwtstate->type == LWTUNNEL_ENCAP_NONE || | |
395 | lwtstate->type > LWTUNNEL_ENCAP_MAX) | |
396 | return 0; | |
397 | ||
398 | ret = -EOPNOTSUPP; | |
399 | rcu_read_lock(); | |
400 | ops = rcu_dereference(lwtun_encaps[lwtstate->type]); | |
401 | if (likely(ops && ops->input)) | |
402 | ret = ops->input(skb); | |
403 | rcu_read_unlock(); | |
404 | ||
405 | if (ret == -EOPNOTSUPP) | |
406 | goto drop; | |
407 | ||
408 | return ret; | |
409 | ||
410 | drop: | |
411 | kfree_skb(skb); | |
412 | ||
413 | return ret; | |
414 | } | |
25368623 | 415 | EXPORT_SYMBOL(lwtunnel_input); |