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23461551 TH |
1 | #include <linux/module.h> |
2 | #include <linux/errno.h> | |
3 | #include <linux/socket.h> | |
4 | #include <linux/skbuff.h> | |
5 | #include <linux/ip.h> | |
6 | #include <linux/udp.h> | |
7 | #include <linux/types.h> | |
8 | #include <linux/kernel.h> | |
9 | #include <net/genetlink.h> | |
37dd0247 | 10 | #include <net/gue.h> |
23461551 | 11 | #include <net/ip.h> |
afe93325 | 12 | #include <net/protocol.h> |
23461551 TH |
13 | #include <net/udp.h> |
14 | #include <net/udp_tunnel.h> | |
15 | #include <net/xfrm.h> | |
16 | #include <uapi/linux/fou.h> | |
17 | #include <uapi/linux/genetlink.h> | |
18 | ||
19 | static DEFINE_SPINLOCK(fou_lock); | |
20 | static LIST_HEAD(fou_list); | |
21 | ||
22 | struct fou { | |
23 | struct socket *sock; | |
24 | u8 protocol; | |
25 | u16 port; | |
afe93325 | 26 | struct udp_offload udp_offloads; |
23461551 TH |
27 | struct list_head list; |
28 | }; | |
29 | ||
30 | struct fou_cfg { | |
37dd0247 | 31 | u16 type; |
23461551 TH |
32 | u8 protocol; |
33 | struct udp_port_cfg udp_config; | |
34 | }; | |
35 | ||
36 | static inline struct fou *fou_from_sock(struct sock *sk) | |
37 | { | |
38 | return sk->sk_user_data; | |
39 | } | |
40 | ||
41 | static int fou_udp_encap_recv_deliver(struct sk_buff *skb, | |
42 | u8 protocol, size_t len) | |
43 | { | |
44 | struct iphdr *iph = ip_hdr(skb); | |
45 | ||
46 | /* Remove 'len' bytes from the packet (UDP header and | |
47 | * FOU header if present), modify the protocol to the one | |
48 | * we found, and then call rcv_encap. | |
49 | */ | |
50 | iph->tot_len = htons(ntohs(iph->tot_len) - len); | |
51 | __skb_pull(skb, len); | |
52 | skb_postpull_rcsum(skb, udp_hdr(skb), len); | |
53 | skb_reset_transport_header(skb); | |
54 | ||
55 | return -protocol; | |
56 | } | |
57 | ||
58 | static int fou_udp_recv(struct sock *sk, struct sk_buff *skb) | |
59 | { | |
60 | struct fou *fou = fou_from_sock(sk); | |
61 | ||
62 | if (!fou) | |
63 | return 1; | |
64 | ||
65 | return fou_udp_encap_recv_deliver(skb, fou->protocol, | |
66 | sizeof(struct udphdr)); | |
67 | } | |
68 | ||
37dd0247 TH |
69 | static int gue_udp_recv(struct sock *sk, struct sk_buff *skb) |
70 | { | |
71 | struct fou *fou = fou_from_sock(sk); | |
72 | size_t len; | |
73 | struct guehdr *guehdr; | |
74 | struct udphdr *uh; | |
75 | ||
76 | if (!fou) | |
77 | return 1; | |
78 | ||
79 | len = sizeof(struct udphdr) + sizeof(struct guehdr); | |
80 | if (!pskb_may_pull(skb, len)) | |
81 | goto drop; | |
82 | ||
83 | uh = udp_hdr(skb); | |
84 | guehdr = (struct guehdr *)&uh[1]; | |
85 | ||
86 | len += guehdr->hlen << 2; | |
87 | if (!pskb_may_pull(skb, len)) | |
88 | goto drop; | |
89 | ||
d8f00d27 LR |
90 | uh = udp_hdr(skb); |
91 | guehdr = (struct guehdr *)&uh[1]; | |
92 | ||
37dd0247 TH |
93 | if (guehdr->version != 0) |
94 | goto drop; | |
95 | ||
96 | if (guehdr->flags) { | |
97 | /* No support yet */ | |
98 | goto drop; | |
99 | } | |
100 | ||
101 | return fou_udp_encap_recv_deliver(skb, guehdr->next_hdr, len); | |
102 | drop: | |
103 | kfree_skb(skb); | |
104 | return 0; | |
105 | } | |
106 | ||
afe93325 | 107 | static struct sk_buff **fou_gro_receive(struct sk_buff **head, |
efc98d08 | 108 | struct sk_buff *skb) |
afe93325 TH |
109 | { |
110 | const struct net_offload *ops; | |
111 | struct sk_buff **pp = NULL; | |
112 | u8 proto = NAPI_GRO_CB(skb)->proto; | |
efc98d08 | 113 | const struct net_offload **offloads; |
afe93325 TH |
114 | |
115 | rcu_read_lock(); | |
efc98d08 | 116 | offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads; |
afe93325 TH |
117 | ops = rcu_dereference(offloads[proto]); |
118 | if (!ops || !ops->callbacks.gro_receive) | |
119 | goto out_unlock; | |
120 | ||
121 | pp = ops->callbacks.gro_receive(head, skb); | |
122 | ||
123 | out_unlock: | |
124 | rcu_read_unlock(); | |
125 | ||
126 | return pp; | |
127 | } | |
128 | ||
efc98d08 | 129 | static int fou_gro_complete(struct sk_buff *skb, int nhoff) |
afe93325 TH |
130 | { |
131 | const struct net_offload *ops; | |
132 | u8 proto = NAPI_GRO_CB(skb)->proto; | |
133 | int err = -ENOSYS; | |
efc98d08 | 134 | const struct net_offload **offloads; |
afe93325 TH |
135 | |
136 | rcu_read_lock(); | |
efc98d08 | 137 | offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads; |
afe93325 TH |
138 | ops = rcu_dereference(offloads[proto]); |
139 | if (WARN_ON(!ops || !ops->callbacks.gro_complete)) | |
140 | goto out_unlock; | |
141 | ||
142 | err = ops->callbacks.gro_complete(skb, nhoff); | |
143 | ||
144 | out_unlock: | |
145 | rcu_read_unlock(); | |
146 | ||
147 | return err; | |
148 | } | |
149 | ||
37dd0247 TH |
150 | static struct sk_buff **gue_gro_receive(struct sk_buff **head, |
151 | struct sk_buff *skb) | |
152 | { | |
153 | const struct net_offload **offloads; | |
154 | const struct net_offload *ops; | |
155 | struct sk_buff **pp = NULL; | |
156 | struct sk_buff *p; | |
157 | u8 proto; | |
158 | struct guehdr *guehdr; | |
159 | unsigned int hlen, guehlen; | |
160 | unsigned int off; | |
161 | int flush = 1; | |
162 | ||
163 | off = skb_gro_offset(skb); | |
164 | hlen = off + sizeof(*guehdr); | |
165 | guehdr = skb_gro_header_fast(skb, off); | |
166 | if (skb_gro_header_hard(skb, hlen)) { | |
167 | guehdr = skb_gro_header_slow(skb, hlen, off); | |
168 | if (unlikely(!guehdr)) | |
169 | goto out; | |
170 | } | |
171 | ||
172 | proto = guehdr->next_hdr; | |
173 | ||
174 | rcu_read_lock(); | |
175 | offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads; | |
176 | ops = rcu_dereference(offloads[proto]); | |
177 | if (WARN_ON(!ops || !ops->callbacks.gro_receive)) | |
178 | goto out_unlock; | |
179 | ||
180 | guehlen = sizeof(*guehdr) + (guehdr->hlen << 2); | |
181 | ||
182 | hlen = off + guehlen; | |
183 | if (skb_gro_header_hard(skb, hlen)) { | |
184 | guehdr = skb_gro_header_slow(skb, hlen, off); | |
185 | if (unlikely(!guehdr)) | |
186 | goto out_unlock; | |
187 | } | |
188 | ||
189 | flush = 0; | |
190 | ||
191 | for (p = *head; p; p = p->next) { | |
192 | const struct guehdr *guehdr2; | |
193 | ||
194 | if (!NAPI_GRO_CB(p)->same_flow) | |
195 | continue; | |
196 | ||
197 | guehdr2 = (struct guehdr *)(p->data + off); | |
198 | ||
199 | /* Compare base GUE header to be equal (covers | |
200 | * hlen, version, next_hdr, and flags. | |
201 | */ | |
202 | if (guehdr->word != guehdr2->word) { | |
203 | NAPI_GRO_CB(p)->same_flow = 0; | |
204 | continue; | |
205 | } | |
206 | ||
207 | /* Compare optional fields are the same. */ | |
208 | if (guehdr->hlen && memcmp(&guehdr[1], &guehdr2[1], | |
209 | guehdr->hlen << 2)) { | |
210 | NAPI_GRO_CB(p)->same_flow = 0; | |
211 | continue; | |
212 | } | |
213 | } | |
214 | ||
215 | skb_gro_pull(skb, guehlen); | |
216 | ||
217 | /* Adjusted NAPI_GRO_CB(skb)->csum after skb_gro_pull()*/ | |
218 | skb_gro_postpull_rcsum(skb, guehdr, guehlen); | |
219 | ||
220 | pp = ops->callbacks.gro_receive(head, skb); | |
221 | ||
222 | out_unlock: | |
223 | rcu_read_unlock(); | |
224 | out: | |
225 | NAPI_GRO_CB(skb)->flush |= flush; | |
226 | ||
227 | return pp; | |
228 | } | |
229 | ||
230 | static int gue_gro_complete(struct sk_buff *skb, int nhoff) | |
231 | { | |
232 | const struct net_offload **offloads; | |
233 | struct guehdr *guehdr = (struct guehdr *)(skb->data + nhoff); | |
234 | const struct net_offload *ops; | |
235 | unsigned int guehlen; | |
236 | u8 proto; | |
237 | int err = -ENOENT; | |
238 | ||
239 | proto = guehdr->next_hdr; | |
240 | ||
241 | guehlen = sizeof(*guehdr) + (guehdr->hlen << 2); | |
242 | ||
243 | rcu_read_lock(); | |
244 | offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads; | |
245 | ops = rcu_dereference(offloads[proto]); | |
246 | if (WARN_ON(!ops || !ops->callbacks.gro_complete)) | |
247 | goto out_unlock; | |
248 | ||
249 | err = ops->callbacks.gro_complete(skb, nhoff + guehlen); | |
250 | ||
251 | out_unlock: | |
252 | rcu_read_unlock(); | |
253 | return err; | |
254 | } | |
255 | ||
23461551 TH |
256 | static int fou_add_to_port_list(struct fou *fou) |
257 | { | |
258 | struct fou *fout; | |
259 | ||
260 | spin_lock(&fou_lock); | |
261 | list_for_each_entry(fout, &fou_list, list) { | |
262 | if (fou->port == fout->port) { | |
263 | spin_unlock(&fou_lock); | |
264 | return -EALREADY; | |
265 | } | |
266 | } | |
267 | ||
268 | list_add(&fou->list, &fou_list); | |
269 | spin_unlock(&fou_lock); | |
270 | ||
271 | return 0; | |
272 | } | |
273 | ||
274 | static void fou_release(struct fou *fou) | |
275 | { | |
276 | struct socket *sock = fou->sock; | |
277 | struct sock *sk = sock->sk; | |
278 | ||
279 | udp_del_offload(&fou->udp_offloads); | |
280 | ||
281 | list_del(&fou->list); | |
282 | ||
283 | /* Remove hooks into tunnel socket */ | |
284 | sk->sk_user_data = NULL; | |
285 | ||
286 | sock_release(sock); | |
287 | ||
288 | kfree(fou); | |
289 | } | |
290 | ||
37dd0247 TH |
291 | static int fou_encap_init(struct sock *sk, struct fou *fou, struct fou_cfg *cfg) |
292 | { | |
293 | udp_sk(sk)->encap_rcv = fou_udp_recv; | |
294 | fou->protocol = cfg->protocol; | |
295 | fou->udp_offloads.callbacks.gro_receive = fou_gro_receive; | |
296 | fou->udp_offloads.callbacks.gro_complete = fou_gro_complete; | |
297 | fou->udp_offloads.port = cfg->udp_config.local_udp_port; | |
298 | fou->udp_offloads.ipproto = cfg->protocol; | |
299 | ||
300 | return 0; | |
301 | } | |
302 | ||
303 | static int gue_encap_init(struct sock *sk, struct fou *fou, struct fou_cfg *cfg) | |
304 | { | |
305 | udp_sk(sk)->encap_rcv = gue_udp_recv; | |
306 | fou->udp_offloads.callbacks.gro_receive = gue_gro_receive; | |
307 | fou->udp_offloads.callbacks.gro_complete = gue_gro_complete; | |
308 | fou->udp_offloads.port = cfg->udp_config.local_udp_port; | |
309 | ||
310 | return 0; | |
311 | } | |
312 | ||
23461551 TH |
313 | static int fou_create(struct net *net, struct fou_cfg *cfg, |
314 | struct socket **sockp) | |
315 | { | |
316 | struct fou *fou = NULL; | |
317 | int err; | |
318 | struct socket *sock = NULL; | |
319 | struct sock *sk; | |
320 | ||
321 | /* Open UDP socket */ | |
322 | err = udp_sock_create(net, &cfg->udp_config, &sock); | |
323 | if (err < 0) | |
324 | goto error; | |
325 | ||
326 | /* Allocate FOU port structure */ | |
327 | fou = kzalloc(sizeof(*fou), GFP_KERNEL); | |
328 | if (!fou) { | |
329 | err = -ENOMEM; | |
330 | goto error; | |
331 | } | |
332 | ||
333 | sk = sock->sk; | |
334 | ||
37dd0247 TH |
335 | fou->port = cfg->udp_config.local_udp_port; |
336 | ||
337 | /* Initial for fou type */ | |
338 | switch (cfg->type) { | |
339 | case FOU_ENCAP_DIRECT: | |
340 | err = fou_encap_init(sk, fou, cfg); | |
341 | if (err) | |
342 | goto error; | |
343 | break; | |
344 | case FOU_ENCAP_GUE: | |
345 | err = gue_encap_init(sk, fou, cfg); | |
346 | if (err) | |
347 | goto error; | |
348 | break; | |
349 | default: | |
350 | err = -EINVAL; | |
351 | goto error; | |
352 | } | |
23461551 TH |
353 | |
354 | udp_sk(sk)->encap_type = 1; | |
355 | udp_encap_enable(); | |
356 | ||
357 | sk->sk_user_data = fou; | |
358 | fou->sock = sock; | |
359 | ||
360 | udp_set_convert_csum(sk, true); | |
361 | ||
362 | sk->sk_allocation = GFP_ATOMIC; | |
363 | ||
afe93325 TH |
364 | if (cfg->udp_config.family == AF_INET) { |
365 | err = udp_add_offload(&fou->udp_offloads); | |
366 | if (err) | |
367 | goto error; | |
368 | } | |
369 | ||
23461551 TH |
370 | err = fou_add_to_port_list(fou); |
371 | if (err) | |
372 | goto error; | |
373 | ||
374 | if (sockp) | |
375 | *sockp = sock; | |
376 | ||
377 | return 0; | |
378 | ||
379 | error: | |
380 | kfree(fou); | |
381 | if (sock) | |
382 | sock_release(sock); | |
383 | ||
384 | return err; | |
385 | } | |
386 | ||
387 | static int fou_destroy(struct net *net, struct fou_cfg *cfg) | |
388 | { | |
389 | struct fou *fou; | |
390 | u16 port = cfg->udp_config.local_udp_port; | |
391 | int err = -EINVAL; | |
392 | ||
393 | spin_lock(&fou_lock); | |
394 | list_for_each_entry(fou, &fou_list, list) { | |
395 | if (fou->port == port) { | |
afe93325 | 396 | udp_del_offload(&fou->udp_offloads); |
23461551 TH |
397 | fou_release(fou); |
398 | err = 0; | |
399 | break; | |
400 | } | |
401 | } | |
402 | spin_unlock(&fou_lock); | |
403 | ||
404 | return err; | |
405 | } | |
406 | ||
407 | static struct genl_family fou_nl_family = { | |
408 | .id = GENL_ID_GENERATE, | |
409 | .hdrsize = 0, | |
410 | .name = FOU_GENL_NAME, | |
411 | .version = FOU_GENL_VERSION, | |
412 | .maxattr = FOU_ATTR_MAX, | |
413 | .netnsok = true, | |
414 | }; | |
415 | ||
416 | static struct nla_policy fou_nl_policy[FOU_ATTR_MAX + 1] = { | |
417 | [FOU_ATTR_PORT] = { .type = NLA_U16, }, | |
418 | [FOU_ATTR_AF] = { .type = NLA_U8, }, | |
419 | [FOU_ATTR_IPPROTO] = { .type = NLA_U8, }, | |
37dd0247 | 420 | [FOU_ATTR_TYPE] = { .type = NLA_U8, }, |
23461551 TH |
421 | }; |
422 | ||
423 | static int parse_nl_config(struct genl_info *info, | |
424 | struct fou_cfg *cfg) | |
425 | { | |
426 | memset(cfg, 0, sizeof(*cfg)); | |
427 | ||
428 | cfg->udp_config.family = AF_INET; | |
429 | ||
430 | if (info->attrs[FOU_ATTR_AF]) { | |
431 | u8 family = nla_get_u8(info->attrs[FOU_ATTR_AF]); | |
432 | ||
433 | if (family != AF_INET && family != AF_INET6) | |
434 | return -EINVAL; | |
435 | ||
436 | cfg->udp_config.family = family; | |
437 | } | |
438 | ||
439 | if (info->attrs[FOU_ATTR_PORT]) { | |
440 | u16 port = nla_get_u16(info->attrs[FOU_ATTR_PORT]); | |
441 | ||
442 | cfg->udp_config.local_udp_port = port; | |
443 | } | |
444 | ||
445 | if (info->attrs[FOU_ATTR_IPPROTO]) | |
446 | cfg->protocol = nla_get_u8(info->attrs[FOU_ATTR_IPPROTO]); | |
447 | ||
37dd0247 TH |
448 | if (info->attrs[FOU_ATTR_TYPE]) |
449 | cfg->type = nla_get_u8(info->attrs[FOU_ATTR_TYPE]); | |
450 | ||
23461551 TH |
451 | return 0; |
452 | } | |
453 | ||
454 | static int fou_nl_cmd_add_port(struct sk_buff *skb, struct genl_info *info) | |
455 | { | |
456 | struct fou_cfg cfg; | |
457 | int err; | |
458 | ||
459 | err = parse_nl_config(info, &cfg); | |
460 | if (err) | |
461 | return err; | |
462 | ||
463 | return fou_create(&init_net, &cfg, NULL); | |
464 | } | |
465 | ||
466 | static int fou_nl_cmd_rm_port(struct sk_buff *skb, struct genl_info *info) | |
467 | { | |
468 | struct fou_cfg cfg; | |
469 | ||
470 | parse_nl_config(info, &cfg); | |
471 | ||
472 | return fou_destroy(&init_net, &cfg); | |
473 | } | |
474 | ||
475 | static const struct genl_ops fou_nl_ops[] = { | |
476 | { | |
477 | .cmd = FOU_CMD_ADD, | |
478 | .doit = fou_nl_cmd_add_port, | |
479 | .policy = fou_nl_policy, | |
480 | .flags = GENL_ADMIN_PERM, | |
481 | }, | |
482 | { | |
483 | .cmd = FOU_CMD_DEL, | |
484 | .doit = fou_nl_cmd_rm_port, | |
485 | .policy = fou_nl_policy, | |
486 | .flags = GENL_ADMIN_PERM, | |
487 | }, | |
488 | }; | |
489 | ||
490 | static int __init fou_init(void) | |
491 | { | |
492 | int ret; | |
493 | ||
494 | ret = genl_register_family_with_ops(&fou_nl_family, | |
495 | fou_nl_ops); | |
496 | ||
497 | return ret; | |
498 | } | |
499 | ||
500 | static void __exit fou_fini(void) | |
501 | { | |
502 | struct fou *fou, *next; | |
503 | ||
504 | genl_unregister_family(&fou_nl_family); | |
505 | ||
506 | /* Close all the FOU sockets */ | |
507 | ||
508 | spin_lock(&fou_lock); | |
509 | list_for_each_entry_safe(fou, next, &fou_list, list) | |
510 | fou_release(fou); | |
511 | spin_unlock(&fou_lock); | |
512 | } | |
513 | ||
514 | module_init(fou_init); | |
515 | module_exit(fou_fini); | |
516 | MODULE_AUTHOR("Tom Herbert <therbert@google.com>"); | |
517 | MODULE_LICENSE("GPL"); |