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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"; | |
d1df6fd8 DL |
47 | case LWTUNNEL_ENCAP_SEG6_LOCAL: |
48 | return "SEG6LOCAL"; | |
745041e2 RS |
49 | case LWTUNNEL_ENCAP_IP6: |
50 | case LWTUNNEL_ENCAP_IP: | |
51 | case LWTUNNEL_ENCAP_NONE: | |
52 | case __LWTUNNEL_ENCAP_MAX: | |
53 | /* should not have got here */ | |
54 | WARN_ON(1); | |
55 | break; | |
56 | } | |
57 | return NULL; | |
58 | } | |
59 | ||
60 | #endif /* CONFIG_MODULES */ | |
61 | ||
499a2425 RP |
62 | struct lwtunnel_state *lwtunnel_state_alloc(int encap_len) |
63 | { | |
64 | struct lwtunnel_state *lws; | |
65 | ||
66 | lws = kzalloc(sizeof(*lws) + encap_len, GFP_ATOMIC); | |
67 | ||
68 | return lws; | |
69 | } | |
08bd10ff | 70 | EXPORT_SYMBOL_GPL(lwtunnel_state_alloc); |
499a2425 | 71 | |
92a99bf3 | 72 | static const struct lwtunnel_encap_ops __rcu * |
499a2425 RP |
73 | lwtun_encaps[LWTUNNEL_ENCAP_MAX + 1] __read_mostly; |
74 | ||
75 | int lwtunnel_encap_add_ops(const struct lwtunnel_encap_ops *ops, | |
76 | unsigned int num) | |
77 | { | |
78 | if (num > LWTUNNEL_ENCAP_MAX) | |
79 | return -ERANGE; | |
80 | ||
81 | return !cmpxchg((const struct lwtunnel_encap_ops **) | |
82 | &lwtun_encaps[num], | |
83 | NULL, ops) ? 0 : -1; | |
84 | } | |
08bd10ff | 85 | EXPORT_SYMBOL_GPL(lwtunnel_encap_add_ops); |
499a2425 RP |
86 | |
87 | int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *ops, | |
88 | unsigned int encap_type) | |
89 | { | |
90 | int ret; | |
91 | ||
92 | if (encap_type == LWTUNNEL_ENCAP_NONE || | |
93 | encap_type > LWTUNNEL_ENCAP_MAX) | |
94 | return -ERANGE; | |
95 | ||
96 | ret = (cmpxchg((const struct lwtunnel_encap_ops **) | |
97 | &lwtun_encaps[encap_type], | |
98 | ops, NULL) == ops) ? 0 : -1; | |
99 | ||
100 | synchronize_net(); | |
101 | ||
102 | return ret; | |
103 | } | |
08bd10ff | 104 | EXPORT_SYMBOL_GPL(lwtunnel_encap_del_ops); |
499a2425 | 105 | |
30357d7d | 106 | int lwtunnel_build_state(u16 encap_type, |
127eb7cd | 107 | struct nlattr *encap, unsigned int family, |
9ae28727 DA |
108 | const void *cfg, struct lwtunnel_state **lws, |
109 | struct netlink_ext_ack *extack) | |
499a2425 RP |
110 | { |
111 | const struct lwtunnel_encap_ops *ops; | |
9ae28727 | 112 | bool found = false; |
499a2425 RP |
113 | int ret = -EINVAL; |
114 | ||
115 | if (encap_type == LWTUNNEL_ENCAP_NONE || | |
9ae28727 DA |
116 | encap_type > LWTUNNEL_ENCAP_MAX) { |
117 | NL_SET_ERR_MSG_ATTR(extack, encap, | |
118 | "Unknown LWT encapsulation type"); | |
499a2425 | 119 | return ret; |
9ae28727 | 120 | } |
499a2425 RP |
121 | |
122 | ret = -EOPNOTSUPP; | |
123 | rcu_read_lock(); | |
124 | ops = rcu_dereference(lwtun_encaps[encap_type]); | |
85c81401 | 125 | if (likely(ops && ops->build_state && try_module_get(ops->owner))) { |
9ae28727 DA |
126 | found = true; |
127 | ret = ops->build_state(encap, family, cfg, lws, extack); | |
85c81401 RS |
128 | if (ret) |
129 | module_put(ops->owner); | |
130 | } | |
9ed59592 DA |
131 | rcu_read_unlock(); |
132 | ||
9ae28727 DA |
133 | /* don't rely on -EOPNOTSUPP to detect match as build_state |
134 | * handlers could return it | |
135 | */ | |
136 | if (!found) { | |
137 | NL_SET_ERR_MSG_ATTR(extack, encap, | |
138 | "LWT encapsulation type not supported"); | |
139 | } | |
140 | ||
9ed59592 DA |
141 | return ret; |
142 | } | |
08bd10ff | 143 | EXPORT_SYMBOL_GPL(lwtunnel_build_state); |
9ed59592 | 144 | |
c255bd68 | 145 | int lwtunnel_valid_encap_type(u16 encap_type, struct netlink_ext_ack *extack) |
9ed59592 DA |
146 | { |
147 | const struct lwtunnel_encap_ops *ops; | |
148 | int ret = -EINVAL; | |
149 | ||
150 | if (encap_type == LWTUNNEL_ENCAP_NONE || | |
c255bd68 DA |
151 | encap_type > LWTUNNEL_ENCAP_MAX) { |
152 | NL_SET_ERR_MSG(extack, "Unknown lwt encapsulation type"); | |
9ed59592 | 153 | return ret; |
c255bd68 | 154 | } |
9ed59592 DA |
155 | |
156 | rcu_read_lock(); | |
157 | ops = rcu_dereference(lwtun_encaps[encap_type]); | |
158 | rcu_read_unlock(); | |
745041e2 RS |
159 | #ifdef CONFIG_MODULES |
160 | if (!ops) { | |
161 | const char *encap_type_str = lwtunnel_encap_str(encap_type); | |
162 | ||
163 | if (encap_type_str) { | |
9ed59592 | 164 | __rtnl_unlock(); |
745041e2 | 165 | request_module("rtnl-lwt-%s", encap_type_str); |
9ed59592 DA |
166 | rtnl_lock(); |
167 | ||
745041e2 RS |
168 | rcu_read_lock(); |
169 | ops = rcu_dereference(lwtun_encaps[encap_type]); | |
9ed59592 | 170 | rcu_read_unlock(); |
745041e2 RS |
171 | } |
172 | } | |
173 | #endif | |
c255bd68 DA |
174 | ret = ops ? 0 : -EOPNOTSUPP; |
175 | if (ret < 0) | |
176 | NL_SET_ERR_MSG(extack, "lwt encapsulation type not supported"); | |
177 | ||
178 | return ret; | |
9ed59592 | 179 | } |
08bd10ff | 180 | EXPORT_SYMBOL_GPL(lwtunnel_valid_encap_type); |
499a2425 | 181 | |
c255bd68 DA |
182 | int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int remaining, |
183 | struct netlink_ext_ack *extack) | |
9ed59592 DA |
184 | { |
185 | struct rtnexthop *rtnh = (struct rtnexthop *)attr; | |
186 | struct nlattr *nla_entype; | |
187 | struct nlattr *attrs; | |
9ed59592 DA |
188 | u16 encap_type; |
189 | int attrlen; | |
190 | ||
191 | while (rtnh_ok(rtnh, remaining)) { | |
192 | attrlen = rtnh_attrlen(rtnh); | |
193 | if (attrlen > 0) { | |
194 | attrs = rtnh_attrs(rtnh); | |
9ed59592 DA |
195 | nla_entype = nla_find(attrs, attrlen, RTA_ENCAP_TYPE); |
196 | ||
197 | if (nla_entype) { | |
198 | encap_type = nla_get_u16(nla_entype); | |
199 | ||
c255bd68 DA |
200 | if (lwtunnel_valid_encap_type(encap_type, |
201 | extack) != 0) | |
9ed59592 DA |
202 | return -EOPNOTSUPP; |
203 | } | |
204 | } | |
205 | rtnh = rtnh_next(rtnh, &remaining); | |
206 | } | |
207 | ||
208 | return 0; | |
499a2425 | 209 | } |
08bd10ff | 210 | EXPORT_SYMBOL_GPL(lwtunnel_valid_encap_type_attr); |
499a2425 | 211 | |
1104d9ba TH |
212 | void lwtstate_free(struct lwtunnel_state *lws) |
213 | { | |
214 | const struct lwtunnel_encap_ops *ops = lwtun_encaps[lws->type]; | |
215 | ||
216 | if (ops->destroy_state) { | |
217 | ops->destroy_state(lws); | |
218 | kfree_rcu(lws, rcu); | |
219 | } else { | |
220 | kfree(lws); | |
221 | } | |
85c81401 | 222 | module_put(ops->owner); |
1104d9ba | 223 | } |
08bd10ff | 224 | EXPORT_SYMBOL_GPL(lwtstate_free); |
1104d9ba | 225 | |
499a2425 RP |
226 | int lwtunnel_fill_encap(struct sk_buff *skb, struct lwtunnel_state *lwtstate) |
227 | { | |
228 | const struct lwtunnel_encap_ops *ops; | |
229 | struct nlattr *nest; | |
39f37095 | 230 | int ret; |
499a2425 RP |
231 | |
232 | if (!lwtstate) | |
233 | return 0; | |
234 | ||
235 | if (lwtstate->type == LWTUNNEL_ENCAP_NONE || | |
236 | lwtstate->type > LWTUNNEL_ENCAP_MAX) | |
237 | return 0; | |
238 | ||
499a2425 | 239 | nest = nla_nest_start(skb, RTA_ENCAP); |
a50fe0ff | 240 | if (!nest) |
39f37095 DC |
241 | return -EMSGSIZE; |
242 | ||
243 | ret = -EOPNOTSUPP; | |
499a2425 RP |
244 | rcu_read_lock(); |
245 | ops = rcu_dereference(lwtun_encaps[lwtstate->type]); | |
246 | if (likely(ops && ops->fill_encap)) | |
247 | ret = ops->fill_encap(skb, lwtstate); | |
248 | rcu_read_unlock(); | |
249 | ||
250 | if (ret) | |
251 | goto nla_put_failure; | |
252 | nla_nest_end(skb, nest); | |
253 | ret = nla_put_u16(skb, RTA_ENCAP_TYPE, lwtstate->type); | |
254 | if (ret) | |
255 | goto nla_put_failure; | |
256 | ||
257 | return 0; | |
258 | ||
259 | nla_put_failure: | |
260 | nla_nest_cancel(skb, nest); | |
261 | ||
262 | return (ret == -EOPNOTSUPP ? 0 : ret); | |
263 | } | |
08bd10ff | 264 | EXPORT_SYMBOL_GPL(lwtunnel_fill_encap); |
499a2425 RP |
265 | |
266 | int lwtunnel_get_encap_size(struct lwtunnel_state *lwtstate) | |
267 | { | |
268 | const struct lwtunnel_encap_ops *ops; | |
269 | int ret = 0; | |
270 | ||
271 | if (!lwtstate) | |
272 | return 0; | |
273 | ||
274 | if (lwtstate->type == LWTUNNEL_ENCAP_NONE || | |
275 | lwtstate->type > LWTUNNEL_ENCAP_MAX) | |
276 | return 0; | |
277 | ||
278 | rcu_read_lock(); | |
279 | ops = rcu_dereference(lwtun_encaps[lwtstate->type]); | |
280 | if (likely(ops && ops->get_encap_size)) | |
281 | ret = nla_total_size(ops->get_encap_size(lwtstate)); | |
282 | rcu_read_unlock(); | |
283 | ||
284 | return ret; | |
285 | } | |
08bd10ff | 286 | EXPORT_SYMBOL_GPL(lwtunnel_get_encap_size); |
499a2425 RP |
287 | |
288 | int lwtunnel_cmp_encap(struct lwtunnel_state *a, struct lwtunnel_state *b) | |
289 | { | |
290 | const struct lwtunnel_encap_ops *ops; | |
291 | int ret = 0; | |
292 | ||
293 | if (!a && !b) | |
294 | return 0; | |
295 | ||
296 | if (!a || !b) | |
297 | return 1; | |
298 | ||
299 | if (a->type != b->type) | |
300 | return 1; | |
301 | ||
302 | if (a->type == LWTUNNEL_ENCAP_NONE || | |
303 | a->type > LWTUNNEL_ENCAP_MAX) | |
304 | return 0; | |
305 | ||
306 | rcu_read_lock(); | |
307 | ops = rcu_dereference(lwtun_encaps[a->type]); | |
308 | if (likely(ops && ops->cmp_encap)) | |
309 | ret = ops->cmp_encap(a, b); | |
310 | rcu_read_unlock(); | |
311 | ||
312 | return ret; | |
313 | } | |
08bd10ff | 314 | EXPORT_SYMBOL_GPL(lwtunnel_cmp_encap); |
ffce4196 | 315 | |
ede2059d | 316 | int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb) |
ffce4196 | 317 | { |
61adedf3 | 318 | struct dst_entry *dst = skb_dst(skb); |
ffce4196 | 319 | const struct lwtunnel_encap_ops *ops; |
61adedf3 | 320 | struct lwtunnel_state *lwtstate; |
ffce4196 RP |
321 | int ret = -EINVAL; |
322 | ||
61adedf3 | 323 | if (!dst) |
ffce4196 | 324 | goto drop; |
61adedf3 | 325 | lwtstate = dst->lwtstate; |
ffce4196 RP |
326 | |
327 | if (lwtstate->type == LWTUNNEL_ENCAP_NONE || | |
328 | lwtstate->type > LWTUNNEL_ENCAP_MAX) | |
329 | return 0; | |
330 | ||
331 | ret = -EOPNOTSUPP; | |
332 | rcu_read_lock(); | |
333 | ops = rcu_dereference(lwtun_encaps[lwtstate->type]); | |
334 | if (likely(ops && ops->output)) | |
ede2059d | 335 | ret = ops->output(net, sk, skb); |
ffce4196 RP |
336 | rcu_read_unlock(); |
337 | ||
338 | if (ret == -EOPNOTSUPP) | |
339 | goto drop; | |
340 | ||
341 | return ret; | |
342 | ||
343 | drop: | |
e11f40b9 | 344 | kfree_skb(skb); |
ffce4196 RP |
345 | |
346 | return ret; | |
347 | } | |
08bd10ff | 348 | EXPORT_SYMBOL_GPL(lwtunnel_output); |
25368623 | 349 | |
14972cbd RP |
350 | int lwtunnel_xmit(struct sk_buff *skb) |
351 | { | |
352 | struct dst_entry *dst = skb_dst(skb); | |
353 | const struct lwtunnel_encap_ops *ops; | |
354 | struct lwtunnel_state *lwtstate; | |
355 | int ret = -EINVAL; | |
356 | ||
357 | if (!dst) | |
358 | goto drop; | |
359 | ||
360 | lwtstate = dst->lwtstate; | |
361 | ||
362 | if (lwtstate->type == LWTUNNEL_ENCAP_NONE || | |
363 | lwtstate->type > LWTUNNEL_ENCAP_MAX) | |
364 | return 0; | |
365 | ||
366 | ret = -EOPNOTSUPP; | |
367 | rcu_read_lock(); | |
368 | ops = rcu_dereference(lwtun_encaps[lwtstate->type]); | |
369 | if (likely(ops && ops->xmit)) | |
370 | ret = ops->xmit(skb); | |
371 | rcu_read_unlock(); | |
372 | ||
373 | if (ret == -EOPNOTSUPP) | |
374 | goto drop; | |
375 | ||
376 | return ret; | |
377 | ||
378 | drop: | |
379 | kfree_skb(skb); | |
380 | ||
381 | return ret; | |
382 | } | |
08bd10ff | 383 | EXPORT_SYMBOL_GPL(lwtunnel_xmit); |
14972cbd | 384 | |
61adedf3 | 385 | int lwtunnel_input(struct sk_buff *skb) |
25368623 | 386 | { |
61adedf3 | 387 | struct dst_entry *dst = skb_dst(skb); |
25368623 | 388 | const struct lwtunnel_encap_ops *ops; |
61adedf3 | 389 | struct lwtunnel_state *lwtstate; |
25368623 TH |
390 | int ret = -EINVAL; |
391 | ||
61adedf3 | 392 | if (!dst) |
25368623 | 393 | goto drop; |
61adedf3 | 394 | lwtstate = dst->lwtstate; |
25368623 TH |
395 | |
396 | if (lwtstate->type == LWTUNNEL_ENCAP_NONE || | |
397 | lwtstate->type > LWTUNNEL_ENCAP_MAX) | |
398 | return 0; | |
399 | ||
400 | ret = -EOPNOTSUPP; | |
401 | rcu_read_lock(); | |
402 | ops = rcu_dereference(lwtun_encaps[lwtstate->type]); | |
403 | if (likely(ops && ops->input)) | |
404 | ret = ops->input(skb); | |
405 | rcu_read_unlock(); | |
406 | ||
407 | if (ret == -EOPNOTSUPP) | |
408 | goto drop; | |
409 | ||
410 | return ret; | |
411 | ||
412 | drop: | |
413 | kfree_skb(skb); | |
414 | ||
415 | return ret; | |
416 | } | |
08bd10ff | 417 | EXPORT_SYMBOL_GPL(lwtunnel_input); |