Commit | Line | Data |
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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 | |
745041e2 RS |
26 | #ifdef CONFIG_MODULES |
27 | ||
28 | static const char *lwtunnel_encap_str(enum lwtunnel_encap_types encap_type) | |
29 | { | |
30 | /* Only lwt encaps implemented without using an interface for | |
31 | * the encap need to return a string here. | |
32 | */ | |
33 | switch (encap_type) { | |
34 | case LWTUNNEL_ENCAP_MPLS: | |
35 | return "MPLS"; | |
36 | case LWTUNNEL_ENCAP_ILA: | |
37 | return "ILA"; | |
6c8702c6 DL |
38 | case LWTUNNEL_ENCAP_SEG6: |
39 | return "SEG6"; | |
3a0af8fd TG |
40 | case LWTUNNEL_ENCAP_BPF: |
41 | return "BPF"; | |
d1df6fd8 DL |
42 | case LWTUNNEL_ENCAP_SEG6_LOCAL: |
43 | return "SEG6LOCAL"; | |
a7a29f9c AA |
44 | case LWTUNNEL_ENCAP_RPL: |
45 | return "RPL"; | |
745041e2 RS |
46 | case LWTUNNEL_ENCAP_IP6: |
47 | case LWTUNNEL_ENCAP_IP: | |
48 | case LWTUNNEL_ENCAP_NONE: | |
49 | case __LWTUNNEL_ENCAP_MAX: | |
50 | /* should not have got here */ | |
51 | WARN_ON(1); | |
52 | break; | |
53 | } | |
54 | return NULL; | |
55 | } | |
56 | ||
57 | #endif /* CONFIG_MODULES */ | |
58 | ||
499a2425 RP |
59 | struct lwtunnel_state *lwtunnel_state_alloc(int encap_len) |
60 | { | |
61 | struct lwtunnel_state *lws; | |
62 | ||
63 | lws = kzalloc(sizeof(*lws) + encap_len, GFP_ATOMIC); | |
64 | ||
65 | return lws; | |
66 | } | |
08bd10ff | 67 | EXPORT_SYMBOL_GPL(lwtunnel_state_alloc); |
499a2425 | 68 | |
92a99bf3 | 69 | static const struct lwtunnel_encap_ops __rcu * |
499a2425 RP |
70 | lwtun_encaps[LWTUNNEL_ENCAP_MAX + 1] __read_mostly; |
71 | ||
72 | int lwtunnel_encap_add_ops(const struct lwtunnel_encap_ops *ops, | |
73 | unsigned int num) | |
74 | { | |
75 | if (num > LWTUNNEL_ENCAP_MAX) | |
76 | return -ERANGE; | |
77 | ||
78 | return !cmpxchg((const struct lwtunnel_encap_ops **) | |
79 | &lwtun_encaps[num], | |
80 | NULL, ops) ? 0 : -1; | |
81 | } | |
08bd10ff | 82 | EXPORT_SYMBOL_GPL(lwtunnel_encap_add_ops); |
499a2425 RP |
83 | |
84 | int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *ops, | |
85 | unsigned int encap_type) | |
86 | { | |
87 | int ret; | |
88 | ||
89 | if (encap_type == LWTUNNEL_ENCAP_NONE || | |
90 | encap_type > LWTUNNEL_ENCAP_MAX) | |
91 | return -ERANGE; | |
92 | ||
93 | ret = (cmpxchg((const struct lwtunnel_encap_ops **) | |
94 | &lwtun_encaps[encap_type], | |
95 | ops, NULL) == ops) ? 0 : -1; | |
96 | ||
97 | synchronize_net(); | |
98 | ||
99 | return ret; | |
100 | } | |
08bd10ff | 101 | EXPORT_SYMBOL_GPL(lwtunnel_encap_del_ops); |
499a2425 | 102 | |
faee6769 | 103 | int lwtunnel_build_state(struct net *net, u16 encap_type, |
127eb7cd | 104 | struct nlattr *encap, unsigned int family, |
9ae28727 DA |
105 | const void *cfg, struct lwtunnel_state **lws, |
106 | struct netlink_ext_ack *extack) | |
499a2425 RP |
107 | { |
108 | const struct lwtunnel_encap_ops *ops; | |
9ae28727 | 109 | bool found = false; |
499a2425 RP |
110 | int ret = -EINVAL; |
111 | ||
112 | if (encap_type == LWTUNNEL_ENCAP_NONE || | |
9ae28727 DA |
113 | encap_type > LWTUNNEL_ENCAP_MAX) { |
114 | NL_SET_ERR_MSG_ATTR(extack, encap, | |
115 | "Unknown LWT encapsulation type"); | |
499a2425 | 116 | return ret; |
9ae28727 | 117 | } |
499a2425 RP |
118 | |
119 | ret = -EOPNOTSUPP; | |
120 | rcu_read_lock(); | |
121 | ops = rcu_dereference(lwtun_encaps[encap_type]); | |
3d25eabb | 122 | if (likely(ops && ops->build_state && try_module_get(ops->owner))) |
9ae28727 | 123 | found = true; |
3d25eabb | 124 | rcu_read_unlock(); |
125 | ||
126 | if (found) { | |
faee6769 | 127 | ret = ops->build_state(net, encap, family, cfg, lws, extack); |
85c81401 RS |
128 | if (ret) |
129 | module_put(ops->owner); | |
3d25eabb | 130 | } else { |
131 | /* don't rely on -EOPNOTSUPP to detect match as build_state | |
132 | * handlers could return it | |
133 | */ | |
9ae28727 DA |
134 | NL_SET_ERR_MSG_ATTR(extack, encap, |
135 | "LWT encapsulation type not supported"); | |
136 | } | |
137 | ||
9ed59592 DA |
138 | return ret; |
139 | } | |
08bd10ff | 140 | EXPORT_SYMBOL_GPL(lwtunnel_build_state); |
9ed59592 | 141 | |
c255bd68 | 142 | int lwtunnel_valid_encap_type(u16 encap_type, struct netlink_ext_ack *extack) |
9ed59592 DA |
143 | { |
144 | const struct lwtunnel_encap_ops *ops; | |
145 | int ret = -EINVAL; | |
146 | ||
147 | if (encap_type == LWTUNNEL_ENCAP_NONE || | |
c255bd68 DA |
148 | encap_type > LWTUNNEL_ENCAP_MAX) { |
149 | NL_SET_ERR_MSG(extack, "Unknown lwt encapsulation type"); | |
9ed59592 | 150 | return ret; |
c255bd68 | 151 | } |
9ed59592 DA |
152 | |
153 | rcu_read_lock(); | |
154 | ops = rcu_dereference(lwtun_encaps[encap_type]); | |
155 | rcu_read_unlock(); | |
745041e2 RS |
156 | #ifdef CONFIG_MODULES |
157 | if (!ops) { | |
158 | const char *encap_type_str = lwtunnel_encap_str(encap_type); | |
159 | ||
160 | if (encap_type_str) { | |
9ed59592 | 161 | __rtnl_unlock(); |
745041e2 | 162 | request_module("rtnl-lwt-%s", encap_type_str); |
9ed59592 DA |
163 | rtnl_lock(); |
164 | ||
745041e2 RS |
165 | rcu_read_lock(); |
166 | ops = rcu_dereference(lwtun_encaps[encap_type]); | |
9ed59592 | 167 | rcu_read_unlock(); |
745041e2 RS |
168 | } |
169 | } | |
170 | #endif | |
c255bd68 DA |
171 | ret = ops ? 0 : -EOPNOTSUPP; |
172 | if (ret < 0) | |
173 | NL_SET_ERR_MSG(extack, "lwt encapsulation type not supported"); | |
174 | ||
175 | return ret; | |
9ed59592 | 176 | } |
08bd10ff | 177 | EXPORT_SYMBOL_GPL(lwtunnel_valid_encap_type); |
499a2425 | 178 | |
c255bd68 DA |
179 | int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int remaining, |
180 | struct netlink_ext_ack *extack) | |
9ed59592 DA |
181 | { |
182 | struct rtnexthop *rtnh = (struct rtnexthop *)attr; | |
183 | struct nlattr *nla_entype; | |
184 | struct nlattr *attrs; | |
9ed59592 DA |
185 | u16 encap_type; |
186 | int attrlen; | |
187 | ||
188 | while (rtnh_ok(rtnh, remaining)) { | |
189 | attrlen = rtnh_attrlen(rtnh); | |
190 | if (attrlen > 0) { | |
191 | attrs = rtnh_attrs(rtnh); | |
9ed59592 DA |
192 | nla_entype = nla_find(attrs, attrlen, RTA_ENCAP_TYPE); |
193 | ||
194 | if (nla_entype) { | |
195 | encap_type = nla_get_u16(nla_entype); | |
196 | ||
c255bd68 DA |
197 | if (lwtunnel_valid_encap_type(encap_type, |
198 | extack) != 0) | |
9ed59592 DA |
199 | return -EOPNOTSUPP; |
200 | } | |
201 | } | |
202 | rtnh = rtnh_next(rtnh, &remaining); | |
203 | } | |
204 | ||
205 | return 0; | |
499a2425 | 206 | } |
08bd10ff | 207 | EXPORT_SYMBOL_GPL(lwtunnel_valid_encap_type_attr); |
499a2425 | 208 | |
1104d9ba TH |
209 | void lwtstate_free(struct lwtunnel_state *lws) |
210 | { | |
211 | const struct lwtunnel_encap_ops *ops = lwtun_encaps[lws->type]; | |
212 | ||
213 | if (ops->destroy_state) { | |
214 | ops->destroy_state(lws); | |
215 | kfree_rcu(lws, rcu); | |
216 | } else { | |
217 | kfree(lws); | |
218 | } | |
85c81401 | 219 | module_put(ops->owner); |
1104d9ba | 220 | } |
08bd10ff | 221 | EXPORT_SYMBOL_GPL(lwtstate_free); |
1104d9ba | 222 | |
ffa8ce54 DA |
223 | int lwtunnel_fill_encap(struct sk_buff *skb, struct lwtunnel_state *lwtstate, |
224 | int encap_attr, int encap_type_attr) | |
499a2425 RP |
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 | ||
ae0be8de | 237 | nest = nla_nest_start_noflag(skb, encap_attr); |
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); | |
ffa8ce54 | 251 | ret = nla_put_u16(skb, encap_type_attr, lwtstate->type); |
499a2425 RP |
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 | } | |
08bd10ff | 262 | EXPORT_SYMBOL_GPL(lwtunnel_fill_encap); |
499a2425 RP |
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 | } | |
08bd10ff | 284 | EXPORT_SYMBOL_GPL(lwtunnel_get_encap_size); |
499a2425 RP |
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 | } | |
08bd10ff | 312 | EXPORT_SYMBOL_GPL(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 | } | |
08bd10ff | 346 | EXPORT_SYMBOL_GPL(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 | } | |
08bd10ff | 381 | EXPORT_SYMBOL_GPL(lwtunnel_xmit); |
14972cbd | 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 | } | |
08bd10ff | 415 | EXPORT_SYMBOL_GPL(lwtunnel_input); |