Commit | Line | Data |
---|---|---|
2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
499a2425 RP |
2 | /* |
3 | * lwtunnel Infrastructure for light weight tunnels like mpls | |
4 | * | |
5 | * Authors: Roopa Prabhu, <roopa@cumulusnetworks.com> | |
499a2425 RP |
6 | */ |
7 | ||
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> | |
ffce4196 | 23 | #include <net/ip6_fib.h> |
3c618c1d | 24 | #include <net/rtnh.h> |
499a2425 | 25 | |
7a3f5b0d RS |
26 | DEFINE_STATIC_KEY_FALSE(nf_hooks_lwtunnel_enabled); |
27 | EXPORT_SYMBOL_GPL(nf_hooks_lwtunnel_enabled); | |
28 | ||
745041e2 RS |
29 | #ifdef CONFIG_MODULES |
30 | ||
31 | static const char *lwtunnel_encap_str(enum lwtunnel_encap_types encap_type) | |
32 | { | |
33 | /* Only lwt encaps implemented without using an interface for | |
34 | * the encap need to return a string here. | |
35 | */ | |
36 | switch (encap_type) { | |
37 | case LWTUNNEL_ENCAP_MPLS: | |
38 | return "MPLS"; | |
39 | case LWTUNNEL_ENCAP_ILA: | |
40 | return "ILA"; | |
6c8702c6 DL |
41 | case LWTUNNEL_ENCAP_SEG6: |
42 | return "SEG6"; | |
3a0af8fd TG |
43 | case LWTUNNEL_ENCAP_BPF: |
44 | return "BPF"; | |
d1df6fd8 DL |
45 | case LWTUNNEL_ENCAP_SEG6_LOCAL: |
46 | return "SEG6LOCAL"; | |
a7a29f9c AA |
47 | case LWTUNNEL_ENCAP_RPL: |
48 | return "RPL"; | |
3edede08 JI |
49 | case LWTUNNEL_ENCAP_IOAM6: |
50 | return "IOAM6"; | |
d83f7040 EB |
51 | case LWTUNNEL_ENCAP_XFRM: |
52 | /* module autoload not supported for encap type */ | |
53 | return NULL; | |
745041e2 RS |
54 | case LWTUNNEL_ENCAP_IP6: |
55 | case LWTUNNEL_ENCAP_IP: | |
56 | case LWTUNNEL_ENCAP_NONE: | |
57 | case __LWTUNNEL_ENCAP_MAX: | |
58 | /* should not have got here */ | |
59 | WARN_ON(1); | |
60 | break; | |
61 | } | |
62 | return NULL; | |
63 | } | |
64 | ||
65 | #endif /* CONFIG_MODULES */ | |
66 | ||
499a2425 RP |
67 | struct lwtunnel_state *lwtunnel_state_alloc(int encap_len) |
68 | { | |
69 | struct lwtunnel_state *lws; | |
70 | ||
71 | lws = kzalloc(sizeof(*lws) + encap_len, GFP_ATOMIC); | |
72 | ||
73 | return lws; | |
74 | } | |
08bd10ff | 75 | EXPORT_SYMBOL_GPL(lwtunnel_state_alloc); |
499a2425 | 76 | |
92a99bf3 | 77 | static const struct lwtunnel_encap_ops __rcu * |
499a2425 RP |
78 | lwtun_encaps[LWTUNNEL_ENCAP_MAX + 1] __read_mostly; |
79 | ||
80 | int lwtunnel_encap_add_ops(const struct lwtunnel_encap_ops *ops, | |
81 | unsigned int num) | |
82 | { | |
83 | if (num > LWTUNNEL_ENCAP_MAX) | |
84 | return -ERANGE; | |
85 | ||
86 | return !cmpxchg((const struct lwtunnel_encap_ops **) | |
87 | &lwtun_encaps[num], | |
88 | NULL, ops) ? 0 : -1; | |
89 | } | |
08bd10ff | 90 | EXPORT_SYMBOL_GPL(lwtunnel_encap_add_ops); |
499a2425 RP |
91 | |
92 | int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *ops, | |
93 | unsigned int encap_type) | |
94 | { | |
95 | int ret; | |
96 | ||
97 | if (encap_type == LWTUNNEL_ENCAP_NONE || | |
98 | encap_type > LWTUNNEL_ENCAP_MAX) | |
99 | return -ERANGE; | |
100 | ||
101 | ret = (cmpxchg((const struct lwtunnel_encap_ops **) | |
102 | &lwtun_encaps[encap_type], | |
103 | ops, NULL) == ops) ? 0 : -1; | |
104 | ||
105 | synchronize_net(); | |
106 | ||
107 | return ret; | |
108 | } | |
08bd10ff | 109 | EXPORT_SYMBOL_GPL(lwtunnel_encap_del_ops); |
499a2425 | 110 | |
faee6769 | 111 | int lwtunnel_build_state(struct net *net, u16 encap_type, |
127eb7cd | 112 | struct nlattr *encap, unsigned int family, |
9ae28727 DA |
113 | const void *cfg, struct lwtunnel_state **lws, |
114 | struct netlink_ext_ack *extack) | |
499a2425 RP |
115 | { |
116 | const struct lwtunnel_encap_ops *ops; | |
9ae28727 | 117 | bool found = false; |
499a2425 RP |
118 | int ret = -EINVAL; |
119 | ||
120 | if (encap_type == LWTUNNEL_ENCAP_NONE || | |
9ae28727 DA |
121 | encap_type > LWTUNNEL_ENCAP_MAX) { |
122 | NL_SET_ERR_MSG_ATTR(extack, encap, | |
123 | "Unknown LWT encapsulation type"); | |
499a2425 | 124 | return ret; |
9ae28727 | 125 | } |
499a2425 RP |
126 | |
127 | ret = -EOPNOTSUPP; | |
128 | rcu_read_lock(); | |
129 | ops = rcu_dereference(lwtun_encaps[encap_type]); | |
3d25eabb | 130 | if (likely(ops && ops->build_state && try_module_get(ops->owner))) |
9ae28727 | 131 | found = true; |
3d25eabb | 132 | rcu_read_unlock(); |
133 | ||
134 | if (found) { | |
faee6769 | 135 | ret = ops->build_state(net, encap, family, cfg, lws, extack); |
85c81401 RS |
136 | if (ret) |
137 | module_put(ops->owner); | |
3d25eabb | 138 | } else { |
139 | /* don't rely on -EOPNOTSUPP to detect match as build_state | |
140 | * handlers could return it | |
141 | */ | |
9ae28727 DA |
142 | NL_SET_ERR_MSG_ATTR(extack, encap, |
143 | "LWT encapsulation type not supported"); | |
144 | } | |
145 | ||
9ed59592 DA |
146 | return ret; |
147 | } | |
08bd10ff | 148 | EXPORT_SYMBOL_GPL(lwtunnel_build_state); |
9ed59592 | 149 | |
c255bd68 | 150 | int lwtunnel_valid_encap_type(u16 encap_type, struct netlink_ext_ack *extack) |
9ed59592 DA |
151 | { |
152 | const struct lwtunnel_encap_ops *ops; | |
153 | int ret = -EINVAL; | |
154 | ||
155 | if (encap_type == LWTUNNEL_ENCAP_NONE || | |
c255bd68 DA |
156 | encap_type > LWTUNNEL_ENCAP_MAX) { |
157 | NL_SET_ERR_MSG(extack, "Unknown lwt encapsulation type"); | |
9ed59592 | 158 | return ret; |
c255bd68 | 159 | } |
9ed59592 DA |
160 | |
161 | rcu_read_lock(); | |
162 | ops = rcu_dereference(lwtun_encaps[encap_type]); | |
163 | rcu_read_unlock(); | |
745041e2 RS |
164 | #ifdef CONFIG_MODULES |
165 | if (!ops) { | |
166 | const char *encap_type_str = lwtunnel_encap_str(encap_type); | |
167 | ||
168 | if (encap_type_str) { | |
9ed59592 | 169 | __rtnl_unlock(); |
745041e2 | 170 | request_module("rtnl-lwt-%s", encap_type_str); |
9ed59592 DA |
171 | rtnl_lock(); |
172 | ||
745041e2 RS |
173 | rcu_read_lock(); |
174 | ops = rcu_dereference(lwtun_encaps[encap_type]); | |
9ed59592 | 175 | rcu_read_unlock(); |
745041e2 RS |
176 | } |
177 | } | |
178 | #endif | |
c255bd68 DA |
179 | ret = ops ? 0 : -EOPNOTSUPP; |
180 | if (ret < 0) | |
181 | NL_SET_ERR_MSG(extack, "lwt encapsulation type not supported"); | |
182 | ||
183 | return ret; | |
9ed59592 | 184 | } |
08bd10ff | 185 | EXPORT_SYMBOL_GPL(lwtunnel_valid_encap_type); |
499a2425 | 186 | |
c255bd68 DA |
187 | int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int remaining, |
188 | struct netlink_ext_ack *extack) | |
9ed59592 DA |
189 | { |
190 | struct rtnexthop *rtnh = (struct rtnexthop *)attr; | |
191 | struct nlattr *nla_entype; | |
192 | struct nlattr *attrs; | |
9ed59592 DA |
193 | u16 encap_type; |
194 | int attrlen; | |
195 | ||
196 | while (rtnh_ok(rtnh, remaining)) { | |
197 | attrlen = rtnh_attrlen(rtnh); | |
198 | if (attrlen > 0) { | |
199 | attrs = rtnh_attrs(rtnh); | |
9ed59592 DA |
200 | nla_entype = nla_find(attrs, attrlen, RTA_ENCAP_TYPE); |
201 | ||
202 | if (nla_entype) { | |
8bda81a4 DA |
203 | if (nla_len(nla_entype) < sizeof(u16)) { |
204 | NL_SET_ERR_MSG(extack, "Invalid RTA_ENCAP_TYPE"); | |
205 | return -EINVAL; | |
206 | } | |
9ed59592 DA |
207 | encap_type = nla_get_u16(nla_entype); |
208 | ||
c255bd68 DA |
209 | if (lwtunnel_valid_encap_type(encap_type, |
210 | extack) != 0) | |
9ed59592 DA |
211 | return -EOPNOTSUPP; |
212 | } | |
213 | } | |
214 | rtnh = rtnh_next(rtnh, &remaining); | |
215 | } | |
216 | ||
217 | return 0; | |
499a2425 | 218 | } |
08bd10ff | 219 | EXPORT_SYMBOL_GPL(lwtunnel_valid_encap_type_attr); |
499a2425 | 220 | |
1104d9ba TH |
221 | void lwtstate_free(struct lwtunnel_state *lws) |
222 | { | |
223 | const struct lwtunnel_encap_ops *ops = lwtun_encaps[lws->type]; | |
224 | ||
225 | if (ops->destroy_state) { | |
226 | ops->destroy_state(lws); | |
227 | kfree_rcu(lws, rcu); | |
228 | } else { | |
229 | kfree(lws); | |
230 | } | |
85c81401 | 231 | module_put(ops->owner); |
1104d9ba | 232 | } |
08bd10ff | 233 | EXPORT_SYMBOL_GPL(lwtstate_free); |
1104d9ba | 234 | |
ffa8ce54 DA |
235 | int lwtunnel_fill_encap(struct sk_buff *skb, struct lwtunnel_state *lwtstate, |
236 | int encap_attr, int encap_type_attr) | |
499a2425 RP |
237 | { |
238 | const struct lwtunnel_encap_ops *ops; | |
239 | struct nlattr *nest; | |
39f37095 | 240 | int ret; |
499a2425 RP |
241 | |
242 | if (!lwtstate) | |
243 | return 0; | |
244 | ||
245 | if (lwtstate->type == LWTUNNEL_ENCAP_NONE || | |
246 | lwtstate->type > LWTUNNEL_ENCAP_MAX) | |
247 | return 0; | |
248 | ||
ae0be8de | 249 | nest = nla_nest_start_noflag(skb, encap_attr); |
a50fe0ff | 250 | if (!nest) |
39f37095 DC |
251 | return -EMSGSIZE; |
252 | ||
253 | ret = -EOPNOTSUPP; | |
499a2425 RP |
254 | rcu_read_lock(); |
255 | ops = rcu_dereference(lwtun_encaps[lwtstate->type]); | |
256 | if (likely(ops && ops->fill_encap)) | |
257 | ret = ops->fill_encap(skb, lwtstate); | |
258 | rcu_read_unlock(); | |
259 | ||
260 | if (ret) | |
261 | goto nla_put_failure; | |
262 | nla_nest_end(skb, nest); | |
ffa8ce54 | 263 | ret = nla_put_u16(skb, encap_type_attr, lwtstate->type); |
499a2425 RP |
264 | if (ret) |
265 | goto nla_put_failure; | |
266 | ||
267 | return 0; | |
268 | ||
269 | nla_put_failure: | |
270 | nla_nest_cancel(skb, nest); | |
271 | ||
272 | return (ret == -EOPNOTSUPP ? 0 : ret); | |
273 | } | |
08bd10ff | 274 | EXPORT_SYMBOL_GPL(lwtunnel_fill_encap); |
499a2425 RP |
275 | |
276 | int lwtunnel_get_encap_size(struct lwtunnel_state *lwtstate) | |
277 | { | |
278 | const struct lwtunnel_encap_ops *ops; | |
279 | int ret = 0; | |
280 | ||
281 | if (!lwtstate) | |
282 | return 0; | |
283 | ||
284 | if (lwtstate->type == LWTUNNEL_ENCAP_NONE || | |
285 | lwtstate->type > LWTUNNEL_ENCAP_MAX) | |
286 | return 0; | |
287 | ||
288 | rcu_read_lock(); | |
289 | ops = rcu_dereference(lwtun_encaps[lwtstate->type]); | |
290 | if (likely(ops && ops->get_encap_size)) | |
291 | ret = nla_total_size(ops->get_encap_size(lwtstate)); | |
292 | rcu_read_unlock(); | |
293 | ||
294 | return ret; | |
295 | } | |
08bd10ff | 296 | EXPORT_SYMBOL_GPL(lwtunnel_get_encap_size); |
499a2425 RP |
297 | |
298 | int lwtunnel_cmp_encap(struct lwtunnel_state *a, struct lwtunnel_state *b) | |
299 | { | |
300 | const struct lwtunnel_encap_ops *ops; | |
301 | int ret = 0; | |
302 | ||
303 | if (!a && !b) | |
304 | return 0; | |
305 | ||
306 | if (!a || !b) | |
307 | return 1; | |
308 | ||
309 | if (a->type != b->type) | |
310 | return 1; | |
311 | ||
312 | if (a->type == LWTUNNEL_ENCAP_NONE || | |
313 | a->type > LWTUNNEL_ENCAP_MAX) | |
314 | return 0; | |
315 | ||
316 | rcu_read_lock(); | |
317 | ops = rcu_dereference(lwtun_encaps[a->type]); | |
318 | if (likely(ops && ops->cmp_encap)) | |
319 | ret = ops->cmp_encap(a, b); | |
320 | rcu_read_unlock(); | |
321 | ||
322 | return ret; | |
323 | } | |
08bd10ff | 324 | EXPORT_SYMBOL_GPL(lwtunnel_cmp_encap); |
ffce4196 | 325 | |
ede2059d | 326 | int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb) |
ffce4196 | 327 | { |
61adedf3 | 328 | struct dst_entry *dst = skb_dst(skb); |
ffce4196 | 329 | const struct lwtunnel_encap_ops *ops; |
61adedf3 | 330 | struct lwtunnel_state *lwtstate; |
ffce4196 RP |
331 | int ret = -EINVAL; |
332 | ||
61adedf3 | 333 | if (!dst) |
ffce4196 | 334 | goto drop; |
61adedf3 | 335 | lwtstate = dst->lwtstate; |
ffce4196 RP |
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->output)) | |
ede2059d | 345 | ret = ops->output(net, sk, skb); |
ffce4196 RP |
346 | rcu_read_unlock(); |
347 | ||
348 | if (ret == -EOPNOTSUPP) | |
349 | goto drop; | |
350 | ||
351 | return ret; | |
352 | ||
353 | drop: | |
e11f40b9 | 354 | kfree_skb(skb); |
ffce4196 RP |
355 | |
356 | return ret; | |
357 | } | |
08bd10ff | 358 | EXPORT_SYMBOL_GPL(lwtunnel_output); |
25368623 | 359 | |
14972cbd RP |
360 | int lwtunnel_xmit(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 | ||
370 | lwtstate = dst->lwtstate; | |
371 | ||
372 | if (lwtstate->type == LWTUNNEL_ENCAP_NONE || | |
373 | lwtstate->type > LWTUNNEL_ENCAP_MAX) | |
374 | return 0; | |
375 | ||
376 | ret = -EOPNOTSUPP; | |
377 | rcu_read_lock(); | |
378 | ops = rcu_dereference(lwtun_encaps[lwtstate->type]); | |
379 | if (likely(ops && ops->xmit)) | |
380 | ret = ops->xmit(skb); | |
381 | rcu_read_unlock(); | |
382 | ||
383 | if (ret == -EOPNOTSUPP) | |
384 | goto drop; | |
385 | ||
386 | return ret; | |
387 | ||
388 | drop: | |
389 | kfree_skb(skb); | |
390 | ||
391 | return ret; | |
392 | } | |
08bd10ff | 393 | EXPORT_SYMBOL_GPL(lwtunnel_xmit); |
14972cbd | 394 | |
61adedf3 | 395 | int lwtunnel_input(struct sk_buff *skb) |
25368623 | 396 | { |
61adedf3 | 397 | struct dst_entry *dst = skb_dst(skb); |
25368623 | 398 | const struct lwtunnel_encap_ops *ops; |
61adedf3 | 399 | struct lwtunnel_state *lwtstate; |
25368623 TH |
400 | int ret = -EINVAL; |
401 | ||
61adedf3 | 402 | if (!dst) |
25368623 | 403 | goto drop; |
61adedf3 | 404 | lwtstate = dst->lwtstate; |
25368623 TH |
405 | |
406 | if (lwtstate->type == LWTUNNEL_ENCAP_NONE || | |
407 | lwtstate->type > LWTUNNEL_ENCAP_MAX) | |
408 | return 0; | |
409 | ||
410 | ret = -EOPNOTSUPP; | |
411 | rcu_read_lock(); | |
412 | ops = rcu_dereference(lwtun_encaps[lwtstate->type]); | |
413 | if (likely(ops && ops->input)) | |
414 | ret = ops->input(skb); | |
415 | rcu_read_unlock(); | |
416 | ||
417 | if (ret == -EOPNOTSUPP) | |
418 | goto drop; | |
419 | ||
420 | return ret; | |
421 | ||
422 | drop: | |
423 | kfree_skb(skb); | |
424 | ||
425 | return ret; | |
426 | } | |
08bd10ff | 427 | EXPORT_SYMBOL_GPL(lwtunnel_input); |