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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>
10#include <net/gue.h>
11#include <net/fou.h>
12#include <net/ip.h>
13#include <net/protocol.h>
14#include <net/udp.h>
15#include <net/udp_tunnel.h>
16#include <net/xfrm.h>
17#include <uapi/linux/fou.h>
18#include <uapi/linux/genetlink.h>
19
20struct fou {
21 struct socket *sock;
22 u8 protocol;
23 u8 flags;
24 __be16 port;
25 u8 family;
26 u16 type;
27 struct list_head list;
28 struct rcu_head rcu;
29};
30
31#define FOU_F_REMCSUM_NOPARTIAL BIT(0)
32
33struct fou_cfg {
34 u16 type;
35 u8 protocol;
36 u8 flags;
37 struct udp_port_cfg udp_config;
38};
39
40static unsigned int fou_net_id;
41
42struct fou_net {
43 struct list_head fou_list;
44 struct mutex fou_lock;
45};
46
47static inline struct fou *fou_from_sock(struct sock *sk)
48{
49 return sk->sk_user_data;
50}
51
52static int fou_recv_pull(struct sk_buff *skb, struct fou *fou, size_t len)
53{
54 /* Remove 'len' bytes from the packet (UDP header and
55 * FOU header if present).
56 */
57 if (fou->family == AF_INET)
58 ip_hdr(skb)->tot_len = htons(ntohs(ip_hdr(skb)->tot_len) - len);
59 else
60 ipv6_hdr(skb)->payload_len =
61 htons(ntohs(ipv6_hdr(skb)->payload_len) - len);
62
63 __skb_pull(skb, len);
64 skb_postpull_rcsum(skb, udp_hdr(skb), len);
65 skb_reset_transport_header(skb);
66 return iptunnel_pull_offloads(skb);
67}
68
69static int fou_udp_recv(struct sock *sk, struct sk_buff *skb)
70{
71 struct fou *fou = fou_from_sock(sk);
72
73 if (!fou)
74 return 1;
75
76 if (fou_recv_pull(skb, fou, sizeof(struct udphdr)))
77 goto drop;
78
79 return -fou->protocol;
80
81drop:
82 kfree_skb(skb);
83 return 0;
84}
85
86static struct guehdr *gue_remcsum(struct sk_buff *skb, struct guehdr *guehdr,
87 void *data, size_t hdrlen, u8 ipproto,
88 bool nopartial)
89{
90 __be16 *pd = data;
91 size_t start = ntohs(pd[0]);
92 size_t offset = ntohs(pd[1]);
93 size_t plen = sizeof(struct udphdr) + hdrlen +
94 max_t(size_t, offset + sizeof(u16), start);
95
96 if (skb->remcsum_offload)
97 return guehdr;
98
99 if (!pskb_may_pull(skb, plen))
100 return NULL;
101 guehdr = (struct guehdr *)&udp_hdr(skb)[1];
102
103 skb_remcsum_process(skb, (void *)guehdr + hdrlen,
104 start, offset, nopartial);
105
106 return guehdr;
107}
108
109static int gue_control_message(struct sk_buff *skb, struct guehdr *guehdr)
110{
111 /* No support yet */
112 kfree_skb(skb);
113 return 0;
114}
115
116static int gue_udp_recv(struct sock *sk, struct sk_buff *skb)
117{
118 struct fou *fou = fou_from_sock(sk);
119 size_t len, optlen, hdrlen;
120 struct guehdr *guehdr;
121 void *data;
122 u16 doffset = 0;
123
124 if (!fou)
125 return 1;
126
127 len = sizeof(struct udphdr) + sizeof(struct guehdr);
128 if (!pskb_may_pull(skb, len))
129 goto drop;
130
131 guehdr = (struct guehdr *)&udp_hdr(skb)[1];
132
133 switch (guehdr->version) {
134 case 0: /* Full GUE header present */
135 break;
136
137 case 1: {
138 /* Direct encasulation of IPv4 or IPv6 */
139
140 int prot;
141
142 switch (((struct iphdr *)guehdr)->version) {
143 case 4:
144 prot = IPPROTO_IPIP;
145 break;
146 case 6:
147 prot = IPPROTO_IPV6;
148 break;
149 default:
150 goto drop;
151 }
152
153 if (fou_recv_pull(skb, fou, sizeof(struct udphdr)))
154 goto drop;
155
156 return -prot;
157 }
158
159 default: /* Undefined version */
160 goto drop;
161 }
162
163 optlen = guehdr->hlen << 2;
164 len += optlen;
165
166 if (!pskb_may_pull(skb, len))
167 goto drop;
168
169 /* guehdr may change after pull */
170 guehdr = (struct guehdr *)&udp_hdr(skb)[1];
171
172 hdrlen = sizeof(struct guehdr) + optlen;
173
174 if (guehdr->version != 0 || validate_gue_flags(guehdr, optlen))
175 goto drop;
176
177 hdrlen = sizeof(struct guehdr) + optlen;
178
179 if (fou->family == AF_INET)
180 ip_hdr(skb)->tot_len = htons(ntohs(ip_hdr(skb)->tot_len) - len);
181 else
182 ipv6_hdr(skb)->payload_len =
183 htons(ntohs(ipv6_hdr(skb)->payload_len) - len);
184
185 /* Pull csum through the guehdr now . This can be used if
186 * there is a remote checksum offload.
187 */
188 skb_postpull_rcsum(skb, udp_hdr(skb), len);
189
190 data = &guehdr[1];
191
192 if (guehdr->flags & GUE_FLAG_PRIV) {
193 __be32 flags = *(__be32 *)(data + doffset);
194
195 doffset += GUE_LEN_PRIV;
196
197 if (flags & GUE_PFLAG_REMCSUM) {
198 guehdr = gue_remcsum(skb, guehdr, data + doffset,
199 hdrlen, guehdr->proto_ctype,
200 !!(fou->flags &
201 FOU_F_REMCSUM_NOPARTIAL));
202 if (!guehdr)
203 goto drop;
204
205 data = &guehdr[1];
206
207 doffset += GUE_PLEN_REMCSUM;
208 }
209 }
210
211 if (unlikely(guehdr->control))
212 return gue_control_message(skb, guehdr);
213
214 __skb_pull(skb, sizeof(struct udphdr) + hdrlen);
215 skb_reset_transport_header(skb);
216
217 if (iptunnel_pull_offloads(skb))
218 goto drop;
219
220 return -guehdr->proto_ctype;
221
222drop:
223 kfree_skb(skb);
224 return 0;
225}
226
227static struct sk_buff **fou_gro_receive(struct sock *sk,
228 struct sk_buff **head,
229 struct sk_buff *skb)
230{
231 const struct net_offload *ops;
232 struct sk_buff **pp = NULL;
233 u8 proto = fou_from_sock(sk)->protocol;
234 const struct net_offload **offloads;
235
236 /* We can clear the encap_mark for FOU as we are essentially doing
237 * one of two possible things. We are either adding an L4 tunnel
238 * header to the outer L3 tunnel header, or we are are simply
239 * treating the GRE tunnel header as though it is a UDP protocol
240 * specific header such as VXLAN or GENEVE.
241 */
242 NAPI_GRO_CB(skb)->encap_mark = 0;
243
244 /* Flag this frame as already having an outer encap header */
245 NAPI_GRO_CB(skb)->is_fou = 1;
246
247 rcu_read_lock();
248 offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads;
249 ops = rcu_dereference(offloads[proto]);
250 if (!ops || !ops->callbacks.gro_receive)
251 goto out_unlock;
252
253 pp = call_gro_receive(ops->callbacks.gro_receive, head, skb);
254
255out_unlock:
256 rcu_read_unlock();
257
258 return pp;
259}
260
261static int fou_gro_complete(struct sock *sk, struct sk_buff *skb,
262 int nhoff)
263{
264 const struct net_offload *ops;
265 u8 proto = fou_from_sock(sk)->protocol;
266 int err = -ENOSYS;
267 const struct net_offload **offloads;
268
269 rcu_read_lock();
270 offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads;
271 ops = rcu_dereference(offloads[proto]);
272 if (WARN_ON(!ops || !ops->callbacks.gro_complete))
273 goto out_unlock;
274
275 err = ops->callbacks.gro_complete(skb, nhoff);
276
277 skb_set_inner_mac_header(skb, nhoff);
278
279out_unlock:
280 rcu_read_unlock();
281
282 return err;
283}
284
285static struct guehdr *gue_gro_remcsum(struct sk_buff *skb, unsigned int off,
286 struct guehdr *guehdr, void *data,
287 size_t hdrlen, struct gro_remcsum *grc,
288 bool nopartial)
289{
290 __be16 *pd = data;
291 size_t start = ntohs(pd[0]);
292 size_t offset = ntohs(pd[1]);
293
294 if (skb->remcsum_offload)
295 return guehdr;
296
297 if (!NAPI_GRO_CB(skb)->csum_valid)
298 return NULL;
299
300 guehdr = skb_gro_remcsum_process(skb, (void *)guehdr, off, hdrlen,
301 start, offset, grc, nopartial);
302
303 skb->remcsum_offload = 1;
304
305 return guehdr;
306}
307
308static struct sk_buff **gue_gro_receive(struct sock *sk,
309 struct sk_buff **head,
310 struct sk_buff *skb)
311{
312 const struct net_offload **offloads;
313 const struct net_offload *ops;
314 struct sk_buff **pp = NULL;
315 struct sk_buff *p;
316 struct guehdr *guehdr;
317 size_t len, optlen, hdrlen, off;
318 void *data;
319 u16 doffset = 0;
320 int flush = 1;
321 struct fou *fou = fou_from_sock(sk);
322 struct gro_remcsum grc;
323 u8 proto;
324
325 skb_gro_remcsum_init(&grc);
326
327 off = skb_gro_offset(skb);
328 len = off + sizeof(*guehdr);
329
330 guehdr = skb_gro_header_fast(skb, off);
331 if (skb_gro_header_hard(skb, len)) {
332 guehdr = skb_gro_header_slow(skb, len, off);
333 if (unlikely(!guehdr))
334 goto out;
335 }
336
337 switch (guehdr->version) {
338 case 0:
339 break;
340 case 1:
341 switch (((struct iphdr *)guehdr)->version) {
342 case 4:
343 proto = IPPROTO_IPIP;
344 break;
345 case 6:
346 proto = IPPROTO_IPV6;
347 break;
348 default:
349 goto out;
350 }
351 goto next_proto;
352 default:
353 goto out;
354 }
355
356 optlen = guehdr->hlen << 2;
357 len += optlen;
358
359 if (skb_gro_header_hard(skb, len)) {
360 guehdr = skb_gro_header_slow(skb, len, off);
361 if (unlikely(!guehdr))
362 goto out;
363 }
364
365 if (unlikely(guehdr->control) || guehdr->version != 0 ||
366 validate_gue_flags(guehdr, optlen))
367 goto out;
368
369 hdrlen = sizeof(*guehdr) + optlen;
370
371 /* Adjust NAPI_GRO_CB(skb)->csum to account for guehdr,
372 * this is needed if there is a remote checkcsum offload.
373 */
374 skb_gro_postpull_rcsum(skb, guehdr, hdrlen);
375
376 data = &guehdr[1];
377
378 if (guehdr->flags & GUE_FLAG_PRIV) {
379 __be32 flags = *(__be32 *)(data + doffset);
380
381 doffset += GUE_LEN_PRIV;
382
383 if (flags & GUE_PFLAG_REMCSUM) {
384 guehdr = gue_gro_remcsum(skb, off, guehdr,
385 data + doffset, hdrlen, &grc,
386 !!(fou->flags &
387 FOU_F_REMCSUM_NOPARTIAL));
388
389 if (!guehdr)
390 goto out;
391
392 data = &guehdr[1];
393
394 doffset += GUE_PLEN_REMCSUM;
395 }
396 }
397
398 skb_gro_pull(skb, hdrlen);
399
400 for (p = *head; p; p = p->next) {
401 const struct guehdr *guehdr2;
402
403 if (!NAPI_GRO_CB(p)->same_flow)
404 continue;
405
406 guehdr2 = (struct guehdr *)(p->data + off);
407
408 /* Compare base GUE header to be equal (covers
409 * hlen, version, proto_ctype, and flags.
410 */
411 if (guehdr->word != guehdr2->word) {
412 NAPI_GRO_CB(p)->same_flow = 0;
413 continue;
414 }
415
416 /* Compare optional fields are the same. */
417 if (guehdr->hlen && memcmp(&guehdr[1], &guehdr2[1],
418 guehdr->hlen << 2)) {
419 NAPI_GRO_CB(p)->same_flow = 0;
420 continue;
421 }
422 }
423
424 proto = guehdr->proto_ctype;
425
426next_proto:
427
428 /* We can clear the encap_mark for GUE as we are essentially doing
429 * one of two possible things. We are either adding an L4 tunnel
430 * header to the outer L3 tunnel header, or we are are simply
431 * treating the GRE tunnel header as though it is a UDP protocol
432 * specific header such as VXLAN or GENEVE.
433 */
434 NAPI_GRO_CB(skb)->encap_mark = 0;
435
436 /* Flag this frame as already having an outer encap header */
437 NAPI_GRO_CB(skb)->is_fou = 1;
438
439 rcu_read_lock();
440 offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads;
441 ops = rcu_dereference(offloads[proto]);
442 if (WARN_ON_ONCE(!ops || !ops->callbacks.gro_receive))
443 goto out_unlock;
444
445 pp = call_gro_receive(ops->callbacks.gro_receive, head, skb);
446 flush = 0;
447
448out_unlock:
449 rcu_read_unlock();
450out:
451 NAPI_GRO_CB(skb)->flush |= flush;
452 skb_gro_remcsum_cleanup(skb, &grc);
453 skb->remcsum_offload = 0;
454
455 return pp;
456}
457
458static int gue_gro_complete(struct sock *sk, struct sk_buff *skb, int nhoff)
459{
460 const struct net_offload **offloads;
461 struct guehdr *guehdr = (struct guehdr *)(skb->data + nhoff);
462 const struct net_offload *ops;
463 unsigned int guehlen = 0;
464 u8 proto;
465 int err = -ENOENT;
466
467 switch (guehdr->version) {
468 case 0:
469 proto = guehdr->proto_ctype;
470 guehlen = sizeof(*guehdr) + (guehdr->hlen << 2);
471 break;
472 case 1:
473 switch (((struct iphdr *)guehdr)->version) {
474 case 4:
475 proto = IPPROTO_IPIP;
476 break;
477 case 6:
478 proto = IPPROTO_IPV6;
479 break;
480 default:
481 return err;
482 }
483 break;
484 default:
485 return err;
486 }
487
488 rcu_read_lock();
489 offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads;
490 ops = rcu_dereference(offloads[proto]);
491 if (WARN_ON(!ops || !ops->callbacks.gro_complete))
492 goto out_unlock;
493
494 err = ops->callbacks.gro_complete(skb, nhoff + guehlen);
495
496 skb_set_inner_mac_header(skb, nhoff + guehlen);
497
498out_unlock:
499 rcu_read_unlock();
500 return err;
501}
502
503static int fou_add_to_port_list(struct net *net, struct fou *fou)
504{
505 struct fou_net *fn = net_generic(net, fou_net_id);
506 struct fou *fout;
507
508 mutex_lock(&fn->fou_lock);
509 list_for_each_entry(fout, &fn->fou_list, list) {
510 if (fou->port == fout->port &&
511 fou->family == fout->family) {
512 mutex_unlock(&fn->fou_lock);
513 return -EALREADY;
514 }
515 }
516
517 list_add(&fou->list, &fn->fou_list);
518 mutex_unlock(&fn->fou_lock);
519
520 return 0;
521}
522
523static void fou_release(struct fou *fou)
524{
525 struct socket *sock = fou->sock;
526
527 list_del(&fou->list);
528 udp_tunnel_sock_release(sock);
529
530 kfree_rcu(fou, rcu);
531}
532
533static int fou_create(struct net *net, struct fou_cfg *cfg,
534 struct socket **sockp)
535{
536 struct socket *sock = NULL;
537 struct fou *fou = NULL;
538 struct sock *sk;
539 struct udp_tunnel_sock_cfg tunnel_cfg;
540 int err;
541
542 /* Open UDP socket */
543 err = udp_sock_create(net, &cfg->udp_config, &sock);
544 if (err < 0)
545 goto error;
546
547 /* Allocate FOU port structure */
548 fou = kzalloc(sizeof(*fou), GFP_KERNEL);
549 if (!fou) {
550 err = -ENOMEM;
551 goto error;
552 }
553
554 sk = sock->sk;
555
556 fou->port = cfg->udp_config.local_udp_port;
557 fou->family = cfg->udp_config.family;
558 fou->flags = cfg->flags;
559 fou->type = cfg->type;
560 fou->sock = sock;
561
562 memset(&tunnel_cfg, 0, sizeof(tunnel_cfg));
563 tunnel_cfg.encap_type = 1;
564 tunnel_cfg.sk_user_data = fou;
565 tunnel_cfg.encap_destroy = NULL;
566
567 /* Initial for fou type */
568 switch (cfg->type) {
569 case FOU_ENCAP_DIRECT:
570 tunnel_cfg.encap_rcv = fou_udp_recv;
571 tunnel_cfg.gro_receive = fou_gro_receive;
572 tunnel_cfg.gro_complete = fou_gro_complete;
573 fou->protocol = cfg->protocol;
574 break;
575 case FOU_ENCAP_GUE:
576 tunnel_cfg.encap_rcv = gue_udp_recv;
577 tunnel_cfg.gro_receive = gue_gro_receive;
578 tunnel_cfg.gro_complete = gue_gro_complete;
579 break;
580 default:
581 err = -EINVAL;
582 goto error;
583 }
584
585 setup_udp_tunnel_sock(net, sock, &tunnel_cfg);
586
587 sk->sk_allocation = GFP_ATOMIC;
588
589 err = fou_add_to_port_list(net, fou);
590 if (err)
591 goto error;
592
593 if (sockp)
594 *sockp = sock;
595
596 return 0;
597
598error:
599 kfree(fou);
600 if (sock)
601 udp_tunnel_sock_release(sock);
602
603 return err;
604}
605
606static int fou_destroy(struct net *net, struct fou_cfg *cfg)
607{
608 struct fou_net *fn = net_generic(net, fou_net_id);
609 __be16 port = cfg->udp_config.local_udp_port;
610 u8 family = cfg->udp_config.family;
611 int err = -EINVAL;
612 struct fou *fou;
613
614 mutex_lock(&fn->fou_lock);
615 list_for_each_entry(fou, &fn->fou_list, list) {
616 if (fou->port == port && fou->family == family) {
617 fou_release(fou);
618 err = 0;
619 break;
620 }
621 }
622 mutex_unlock(&fn->fou_lock);
623
624 return err;
625}
626
627static struct genl_family fou_nl_family;
628
629static const struct nla_policy fou_nl_policy[FOU_ATTR_MAX + 1] = {
630 [FOU_ATTR_PORT] = { .type = NLA_U16, },
631 [FOU_ATTR_AF] = { .type = NLA_U8, },
632 [FOU_ATTR_IPPROTO] = { .type = NLA_U8, },
633 [FOU_ATTR_TYPE] = { .type = NLA_U8, },
634 [FOU_ATTR_REMCSUM_NOPARTIAL] = { .type = NLA_FLAG, },
635};
636
637static int parse_nl_config(struct genl_info *info,
638 struct fou_cfg *cfg)
639{
640 memset(cfg, 0, sizeof(*cfg));
641
642 cfg->udp_config.family = AF_INET;
643
644 if (info->attrs[FOU_ATTR_AF]) {
645 u8 family = nla_get_u8(info->attrs[FOU_ATTR_AF]);
646
647 switch (family) {
648 case AF_INET:
649 break;
650 case AF_INET6:
651 cfg->udp_config.ipv6_v6only = 1;
652 break;
653 default:
654 return -EAFNOSUPPORT;
655 }
656
657 cfg->udp_config.family = family;
658 }
659
660 if (info->attrs[FOU_ATTR_PORT]) {
661 __be16 port = nla_get_be16(info->attrs[FOU_ATTR_PORT]);
662
663 cfg->udp_config.local_udp_port = port;
664 }
665
666 if (info->attrs[FOU_ATTR_IPPROTO])
667 cfg->protocol = nla_get_u8(info->attrs[FOU_ATTR_IPPROTO]);
668
669 if (info->attrs[FOU_ATTR_TYPE])
670 cfg->type = nla_get_u8(info->attrs[FOU_ATTR_TYPE]);
671
672 if (info->attrs[FOU_ATTR_REMCSUM_NOPARTIAL])
673 cfg->flags |= FOU_F_REMCSUM_NOPARTIAL;
674
675 return 0;
676}
677
678static int fou_nl_cmd_add_port(struct sk_buff *skb, struct genl_info *info)
679{
680 struct net *net = genl_info_net(info);
681 struct fou_cfg cfg;
682 int err;
683
684 err = parse_nl_config(info, &cfg);
685 if (err)
686 return err;
687
688 return fou_create(net, &cfg, NULL);
689}
690
691static int fou_nl_cmd_rm_port(struct sk_buff *skb, struct genl_info *info)
692{
693 struct net *net = genl_info_net(info);
694 struct fou_cfg cfg;
695 int err;
696
697 err = parse_nl_config(info, &cfg);
698 if (err)
699 return err;
700
701 return fou_destroy(net, &cfg);
702}
703
704static int fou_fill_info(struct fou *fou, struct sk_buff *msg)
705{
706 if (nla_put_u8(msg, FOU_ATTR_AF, fou->sock->sk->sk_family) ||
707 nla_put_be16(msg, FOU_ATTR_PORT, fou->port) ||
708 nla_put_u8(msg, FOU_ATTR_IPPROTO, fou->protocol) ||
709 nla_put_u8(msg, FOU_ATTR_TYPE, fou->type))
710 return -1;
711
712 if (fou->flags & FOU_F_REMCSUM_NOPARTIAL)
713 if (nla_put_flag(msg, FOU_ATTR_REMCSUM_NOPARTIAL))
714 return -1;
715 return 0;
716}
717
718static int fou_dump_info(struct fou *fou, u32 portid, u32 seq,
719 u32 flags, struct sk_buff *skb, u8 cmd)
720{
721 void *hdr;
722
723 hdr = genlmsg_put(skb, portid, seq, &fou_nl_family, flags, cmd);
724 if (!hdr)
725 return -ENOMEM;
726
727 if (fou_fill_info(fou, skb) < 0)
728 goto nla_put_failure;
729
730 genlmsg_end(skb, hdr);
731 return 0;
732
733nla_put_failure:
734 genlmsg_cancel(skb, hdr);
735 return -EMSGSIZE;
736}
737
738static int fou_nl_cmd_get_port(struct sk_buff *skb, struct genl_info *info)
739{
740 struct net *net = genl_info_net(info);
741 struct fou_net *fn = net_generic(net, fou_net_id);
742 struct sk_buff *msg;
743 struct fou_cfg cfg;
744 struct fou *fout;
745 __be16 port;
746 u8 family;
747 int ret;
748
749 ret = parse_nl_config(info, &cfg);
750 if (ret)
751 return ret;
752 port = cfg.udp_config.local_udp_port;
753 if (port == 0)
754 return -EINVAL;
755
756 family = cfg.udp_config.family;
757 if (family != AF_INET && family != AF_INET6)
758 return -EINVAL;
759
760 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
761 if (!msg)
762 return -ENOMEM;
763
764 ret = -ESRCH;
765 mutex_lock(&fn->fou_lock);
766 list_for_each_entry(fout, &fn->fou_list, list) {
767 if (port == fout->port && family == fout->family) {
768 ret = fou_dump_info(fout, info->snd_portid,
769 info->snd_seq, 0, msg,
770 info->genlhdr->cmd);
771 break;
772 }
773 }
774 mutex_unlock(&fn->fou_lock);
775 if (ret < 0)
776 goto out_free;
777
778 return genlmsg_reply(msg, info);
779
780out_free:
781 nlmsg_free(msg);
782 return ret;
783}
784
785static int fou_nl_dump(struct sk_buff *skb, struct netlink_callback *cb)
786{
787 struct net *net = sock_net(skb->sk);
788 struct fou_net *fn = net_generic(net, fou_net_id);
789 struct fou *fout;
790 int idx = 0, ret;
791
792 mutex_lock(&fn->fou_lock);
793 list_for_each_entry(fout, &fn->fou_list, list) {
794 if (idx++ < cb->args[0])
795 continue;
796 ret = fou_dump_info(fout, NETLINK_CB(cb->skb).portid,
797 cb->nlh->nlmsg_seq, NLM_F_MULTI,
798 skb, FOU_CMD_GET);
799 if (ret)
800 break;
801 }
802 mutex_unlock(&fn->fou_lock);
803
804 cb->args[0] = idx;
805 return skb->len;
806}
807
808static const struct genl_ops fou_nl_ops[] = {
809 {
810 .cmd = FOU_CMD_ADD,
811 .doit = fou_nl_cmd_add_port,
812 .policy = fou_nl_policy,
813 .flags = GENL_ADMIN_PERM,
814 },
815 {
816 .cmd = FOU_CMD_DEL,
817 .doit = fou_nl_cmd_rm_port,
818 .policy = fou_nl_policy,
819 .flags = GENL_ADMIN_PERM,
820 },
821 {
822 .cmd = FOU_CMD_GET,
823 .doit = fou_nl_cmd_get_port,
824 .dumpit = fou_nl_dump,
825 .policy = fou_nl_policy,
826 },
827};
828
829static struct genl_family fou_nl_family __ro_after_init = {
830 .hdrsize = 0,
831 .name = FOU_GENL_NAME,
832 .version = FOU_GENL_VERSION,
833 .maxattr = FOU_ATTR_MAX,
834 .netnsok = true,
835 .module = THIS_MODULE,
836 .ops = fou_nl_ops,
837 .n_ops = ARRAY_SIZE(fou_nl_ops),
838};
839
840size_t fou_encap_hlen(struct ip_tunnel_encap *e)
841{
842 return sizeof(struct udphdr);
843}
844EXPORT_SYMBOL(fou_encap_hlen);
845
846size_t gue_encap_hlen(struct ip_tunnel_encap *e)
847{
848 size_t len;
849 bool need_priv = false;
850
851 len = sizeof(struct udphdr) + sizeof(struct guehdr);
852
853 if (e->flags & TUNNEL_ENCAP_FLAG_REMCSUM) {
854 len += GUE_PLEN_REMCSUM;
855 need_priv = true;
856 }
857
858 len += need_priv ? GUE_LEN_PRIV : 0;
859
860 return len;
861}
862EXPORT_SYMBOL(gue_encap_hlen);
863
864int __fou_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
865 u8 *protocol, __be16 *sport, int type)
866{
867 int err;
868
869 err = iptunnel_handle_offloads(skb, type);
870 if (err)
871 return err;
872
873 *sport = e->sport ? : udp_flow_src_port(dev_net(skb->dev),
874 skb, 0, 0, false);
875
876 return 0;
877}
878EXPORT_SYMBOL(__fou_build_header);
879
880int __gue_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
881 u8 *protocol, __be16 *sport, int type)
882{
883 struct guehdr *guehdr;
884 size_t hdrlen, optlen = 0;
885 void *data;
886 bool need_priv = false;
887 int err;
888
889 if ((e->flags & TUNNEL_ENCAP_FLAG_REMCSUM) &&
890 skb->ip_summed == CHECKSUM_PARTIAL) {
891 optlen += GUE_PLEN_REMCSUM;
892 type |= SKB_GSO_TUNNEL_REMCSUM;
893 need_priv = true;
894 }
895
896 optlen += need_priv ? GUE_LEN_PRIV : 0;
897
898 err = iptunnel_handle_offloads(skb, type);
899 if (err)
900 return err;
901
902 /* Get source port (based on flow hash) before skb_push */
903 *sport = e->sport ? : udp_flow_src_port(dev_net(skb->dev),
904 skb, 0, 0, false);
905
906 hdrlen = sizeof(struct guehdr) + optlen;
907
908 skb_push(skb, hdrlen);
909
910 guehdr = (struct guehdr *)skb->data;
911
912 guehdr->control = 0;
913 guehdr->version = 0;
914 guehdr->hlen = optlen >> 2;
915 guehdr->flags = 0;
916 guehdr->proto_ctype = *protocol;
917
918 data = &guehdr[1];
919
920 if (need_priv) {
921 __be32 *flags = data;
922
923 guehdr->flags |= GUE_FLAG_PRIV;
924 *flags = 0;
925 data += GUE_LEN_PRIV;
926
927 if (type & SKB_GSO_TUNNEL_REMCSUM) {
928 u16 csum_start = skb_checksum_start_offset(skb);
929 __be16 *pd = data;
930
931 if (csum_start < hdrlen)
932 return -EINVAL;
933
934 csum_start -= hdrlen;
935 pd[0] = htons(csum_start);
936 pd[1] = htons(csum_start + skb->csum_offset);
937
938 if (!skb_is_gso(skb)) {
939 skb->ip_summed = CHECKSUM_NONE;
940 skb->encapsulation = 0;
941 }
942
943 *flags |= GUE_PFLAG_REMCSUM;
944 data += GUE_PLEN_REMCSUM;
945 }
946
947 }
948
949 return 0;
950}
951EXPORT_SYMBOL(__gue_build_header);
952
953#ifdef CONFIG_NET_FOU_IP_TUNNELS
954
955static void fou_build_udp(struct sk_buff *skb, struct ip_tunnel_encap *e,
956 struct flowi4 *fl4, u8 *protocol, __be16 sport)
957{
958 struct udphdr *uh;
959
960 skb_push(skb, sizeof(struct udphdr));
961 skb_reset_transport_header(skb);
962
963 uh = udp_hdr(skb);
964
965 uh->dest = e->dport;
966 uh->source = sport;
967 uh->len = htons(skb->len);
968 udp_set_csum(!(e->flags & TUNNEL_ENCAP_FLAG_CSUM), skb,
969 fl4->saddr, fl4->daddr, skb->len);
970
971 *protocol = IPPROTO_UDP;
972}
973
974static int fou_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
975 u8 *protocol, struct flowi4 *fl4)
976{
977 int type = e->flags & TUNNEL_ENCAP_FLAG_CSUM ? SKB_GSO_UDP_TUNNEL_CSUM :
978 SKB_GSO_UDP_TUNNEL;
979 __be16 sport;
980 int err;
981
982 err = __fou_build_header(skb, e, protocol, &sport, type);
983 if (err)
984 return err;
985
986 fou_build_udp(skb, e, fl4, protocol, sport);
987
988 return 0;
989}
990
991static int gue_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
992 u8 *protocol, struct flowi4 *fl4)
993{
994 int type = e->flags & TUNNEL_ENCAP_FLAG_CSUM ? SKB_GSO_UDP_TUNNEL_CSUM :
995 SKB_GSO_UDP_TUNNEL;
996 __be16 sport;
997 int err;
998
999 err = __gue_build_header(skb, e, protocol, &sport, type);
1000 if (err)
1001 return err;
1002
1003 fou_build_udp(skb, e, fl4, protocol, sport);
1004
1005 return 0;
1006}
1007
1008
1009static const struct ip_tunnel_encap_ops fou_iptun_ops = {
1010 .encap_hlen = fou_encap_hlen,
1011 .build_header = fou_build_header,
1012};
1013
1014static const struct ip_tunnel_encap_ops gue_iptun_ops = {
1015 .encap_hlen = gue_encap_hlen,
1016 .build_header = gue_build_header,
1017};
1018
1019static int ip_tunnel_encap_add_fou_ops(void)
1020{
1021 int ret;
1022
1023 ret = ip_tunnel_encap_add_ops(&fou_iptun_ops, TUNNEL_ENCAP_FOU);
1024 if (ret < 0) {
1025 pr_err("can't add fou ops\n");
1026 return ret;
1027 }
1028
1029 ret = ip_tunnel_encap_add_ops(&gue_iptun_ops, TUNNEL_ENCAP_GUE);
1030 if (ret < 0) {
1031 pr_err("can't add gue ops\n");
1032 ip_tunnel_encap_del_ops(&fou_iptun_ops, TUNNEL_ENCAP_FOU);
1033 return ret;
1034 }
1035
1036 return 0;
1037}
1038
1039static void ip_tunnel_encap_del_fou_ops(void)
1040{
1041 ip_tunnel_encap_del_ops(&fou_iptun_ops, TUNNEL_ENCAP_FOU);
1042 ip_tunnel_encap_del_ops(&gue_iptun_ops, TUNNEL_ENCAP_GUE);
1043}
1044
1045#else
1046
1047static int ip_tunnel_encap_add_fou_ops(void)
1048{
1049 return 0;
1050}
1051
1052static void ip_tunnel_encap_del_fou_ops(void)
1053{
1054}
1055
1056#endif
1057
1058static __net_init int fou_init_net(struct net *net)
1059{
1060 struct fou_net *fn = net_generic(net, fou_net_id);
1061
1062 INIT_LIST_HEAD(&fn->fou_list);
1063 mutex_init(&fn->fou_lock);
1064 return 0;
1065}
1066
1067static __net_exit void fou_exit_net(struct net *net)
1068{
1069 struct fou_net *fn = net_generic(net, fou_net_id);
1070 struct fou *fou, *next;
1071
1072 /* Close all the FOU sockets */
1073 mutex_lock(&fn->fou_lock);
1074 list_for_each_entry_safe(fou, next, &fn->fou_list, list)
1075 fou_release(fou);
1076 mutex_unlock(&fn->fou_lock);
1077}
1078
1079static struct pernet_operations fou_net_ops = {
1080 .init = fou_init_net,
1081 .exit = fou_exit_net,
1082 .id = &fou_net_id,
1083 .size = sizeof(struct fou_net),
1084};
1085
1086static int __init fou_init(void)
1087{
1088 int ret;
1089
1090 ret = register_pernet_device(&fou_net_ops);
1091 if (ret)
1092 goto exit;
1093
1094 ret = genl_register_family(&fou_nl_family);
1095 if (ret < 0)
1096 goto unregister;
1097
1098 ret = ip_tunnel_encap_add_fou_ops();
1099 if (ret == 0)
1100 return 0;
1101
1102 genl_unregister_family(&fou_nl_family);
1103unregister:
1104 unregister_pernet_device(&fou_net_ops);
1105exit:
1106 return ret;
1107}
1108
1109static void __exit fou_fini(void)
1110{
1111 ip_tunnel_encap_del_fou_ops();
1112 genl_unregister_family(&fou_nl_family);
1113 unregister_pernet_device(&fou_net_ops);
1114}
1115
1116module_init(fou_init);
1117module_exit(fou_fini);
1118MODULE_AUTHOR("Tom Herbert <therbert@google.com>");
1119MODULE_LICENSE("GPL");
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>
10#include <net/gue.h>
11#include <net/ip.h>
12#include <net/protocol.h>
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
19struct fou {
20 struct socket *sock;
21 u8 protocol;
22 u8 flags;
23 __be16 port;
24 u16 type;
25 struct udp_offload udp_offloads;
26 struct list_head list;
27 struct rcu_head rcu;
28};
29
30#define FOU_F_REMCSUM_NOPARTIAL BIT(0)
31
32struct fou_cfg {
33 u16 type;
34 u8 protocol;
35 u8 flags;
36 struct udp_port_cfg udp_config;
37};
38
39static unsigned int fou_net_id;
40
41struct fou_net {
42 struct list_head fou_list;
43 struct mutex fou_lock;
44};
45
46static inline struct fou *fou_from_sock(struct sock *sk)
47{
48 return sk->sk_user_data;
49}
50
51static int fou_recv_pull(struct sk_buff *skb, size_t len)
52{
53 struct iphdr *iph = ip_hdr(skb);
54
55 /* Remove 'len' bytes from the packet (UDP header and
56 * FOU header if present).
57 */
58 iph->tot_len = htons(ntohs(iph->tot_len) - len);
59 __skb_pull(skb, len);
60 skb_postpull_rcsum(skb, udp_hdr(skb), len);
61 skb_reset_transport_header(skb);
62 return iptunnel_pull_offloads(skb);
63}
64
65static int fou_udp_recv(struct sock *sk, struct sk_buff *skb)
66{
67 struct fou *fou = fou_from_sock(sk);
68
69 if (!fou)
70 return 1;
71
72 if (fou_recv_pull(skb, sizeof(struct udphdr)))
73 goto drop;
74
75 return -fou->protocol;
76
77drop:
78 kfree_skb(skb);
79 return 0;
80}
81
82static struct guehdr *gue_remcsum(struct sk_buff *skb, struct guehdr *guehdr,
83 void *data, size_t hdrlen, u8 ipproto,
84 bool nopartial)
85{
86 __be16 *pd = data;
87 size_t start = ntohs(pd[0]);
88 size_t offset = ntohs(pd[1]);
89 size_t plen = sizeof(struct udphdr) + hdrlen +
90 max_t(size_t, offset + sizeof(u16), start);
91
92 if (skb->remcsum_offload)
93 return guehdr;
94
95 if (!pskb_may_pull(skb, plen))
96 return NULL;
97 guehdr = (struct guehdr *)&udp_hdr(skb)[1];
98
99 skb_remcsum_process(skb, (void *)guehdr + hdrlen,
100 start, offset, nopartial);
101
102 return guehdr;
103}
104
105static int gue_control_message(struct sk_buff *skb, struct guehdr *guehdr)
106{
107 /* No support yet */
108 kfree_skb(skb);
109 return 0;
110}
111
112static int gue_udp_recv(struct sock *sk, struct sk_buff *skb)
113{
114 struct fou *fou = fou_from_sock(sk);
115 size_t len, optlen, hdrlen;
116 struct guehdr *guehdr;
117 void *data;
118 u16 doffset = 0;
119
120 if (!fou)
121 return 1;
122
123 len = sizeof(struct udphdr) + sizeof(struct guehdr);
124 if (!pskb_may_pull(skb, len))
125 goto drop;
126
127 guehdr = (struct guehdr *)&udp_hdr(skb)[1];
128
129 optlen = guehdr->hlen << 2;
130 len += optlen;
131
132 if (!pskb_may_pull(skb, len))
133 goto drop;
134
135 /* guehdr may change after pull */
136 guehdr = (struct guehdr *)&udp_hdr(skb)[1];
137
138 hdrlen = sizeof(struct guehdr) + optlen;
139
140 if (guehdr->version != 0 || validate_gue_flags(guehdr, optlen))
141 goto drop;
142
143 hdrlen = sizeof(struct guehdr) + optlen;
144
145 ip_hdr(skb)->tot_len = htons(ntohs(ip_hdr(skb)->tot_len) - len);
146
147 /* Pull csum through the guehdr now . This can be used if
148 * there is a remote checksum offload.
149 */
150 skb_postpull_rcsum(skb, udp_hdr(skb), len);
151
152 data = &guehdr[1];
153
154 if (guehdr->flags & GUE_FLAG_PRIV) {
155 __be32 flags = *(__be32 *)(data + doffset);
156
157 doffset += GUE_LEN_PRIV;
158
159 if (flags & GUE_PFLAG_REMCSUM) {
160 guehdr = gue_remcsum(skb, guehdr, data + doffset,
161 hdrlen, guehdr->proto_ctype,
162 !!(fou->flags &
163 FOU_F_REMCSUM_NOPARTIAL));
164 if (!guehdr)
165 goto drop;
166
167 data = &guehdr[1];
168
169 doffset += GUE_PLEN_REMCSUM;
170 }
171 }
172
173 if (unlikely(guehdr->control))
174 return gue_control_message(skb, guehdr);
175
176 __skb_pull(skb, sizeof(struct udphdr) + hdrlen);
177 skb_reset_transport_header(skb);
178
179 if (iptunnel_pull_offloads(skb))
180 goto drop;
181
182 return -guehdr->proto_ctype;
183
184drop:
185 kfree_skb(skb);
186 return 0;
187}
188
189static struct sk_buff **fou_gro_receive(struct sk_buff **head,
190 struct sk_buff *skb,
191 struct udp_offload *uoff)
192{
193 const struct net_offload *ops;
194 struct sk_buff **pp = NULL;
195 u8 proto = NAPI_GRO_CB(skb)->proto;
196 const struct net_offload **offloads;
197
198 /* We can clear the encap_mark for FOU as we are essentially doing
199 * one of two possible things. We are either adding an L4 tunnel
200 * header to the outer L3 tunnel header, or we are are simply
201 * treating the GRE tunnel header as though it is a UDP protocol
202 * specific header such as VXLAN or GENEVE.
203 */
204 NAPI_GRO_CB(skb)->encap_mark = 0;
205
206 /* Flag this frame as already having an outer encap header */
207 NAPI_GRO_CB(skb)->is_fou = 1;
208
209 rcu_read_lock();
210 offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads;
211 ops = rcu_dereference(offloads[proto]);
212 if (!ops || !ops->callbacks.gro_receive)
213 goto out_unlock;
214
215 pp = ops->callbacks.gro_receive(head, skb);
216
217out_unlock:
218 rcu_read_unlock();
219
220 return pp;
221}
222
223static int fou_gro_complete(struct sk_buff *skb, int nhoff,
224 struct udp_offload *uoff)
225{
226 const struct net_offload *ops;
227 u8 proto = NAPI_GRO_CB(skb)->proto;
228 int err = -ENOSYS;
229 const struct net_offload **offloads;
230
231 rcu_read_lock();
232 offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads;
233 ops = rcu_dereference(offloads[proto]);
234 if (WARN_ON(!ops || !ops->callbacks.gro_complete))
235 goto out_unlock;
236
237 err = ops->callbacks.gro_complete(skb, nhoff);
238
239 skb_set_inner_mac_header(skb, nhoff);
240
241out_unlock:
242 rcu_read_unlock();
243
244 return err;
245}
246
247static struct guehdr *gue_gro_remcsum(struct sk_buff *skb, unsigned int off,
248 struct guehdr *guehdr, void *data,
249 size_t hdrlen, struct gro_remcsum *grc,
250 bool nopartial)
251{
252 __be16 *pd = data;
253 size_t start = ntohs(pd[0]);
254 size_t offset = ntohs(pd[1]);
255
256 if (skb->remcsum_offload)
257 return guehdr;
258
259 if (!NAPI_GRO_CB(skb)->csum_valid)
260 return NULL;
261
262 guehdr = skb_gro_remcsum_process(skb, (void *)guehdr, off, hdrlen,
263 start, offset, grc, nopartial);
264
265 skb->remcsum_offload = 1;
266
267 return guehdr;
268}
269
270static struct sk_buff **gue_gro_receive(struct sk_buff **head,
271 struct sk_buff *skb,
272 struct udp_offload *uoff)
273{
274 const struct net_offload **offloads;
275 const struct net_offload *ops;
276 struct sk_buff **pp = NULL;
277 struct sk_buff *p;
278 struct guehdr *guehdr;
279 size_t len, optlen, hdrlen, off;
280 void *data;
281 u16 doffset = 0;
282 int flush = 1;
283 struct fou *fou = container_of(uoff, struct fou, udp_offloads);
284 struct gro_remcsum grc;
285
286 skb_gro_remcsum_init(&grc);
287
288 off = skb_gro_offset(skb);
289 len = off + sizeof(*guehdr);
290
291 guehdr = skb_gro_header_fast(skb, off);
292 if (skb_gro_header_hard(skb, len)) {
293 guehdr = skb_gro_header_slow(skb, len, off);
294 if (unlikely(!guehdr))
295 goto out;
296 }
297
298 optlen = guehdr->hlen << 2;
299 len += optlen;
300
301 if (skb_gro_header_hard(skb, len)) {
302 guehdr = skb_gro_header_slow(skb, len, off);
303 if (unlikely(!guehdr))
304 goto out;
305 }
306
307 if (unlikely(guehdr->control) || guehdr->version != 0 ||
308 validate_gue_flags(guehdr, optlen))
309 goto out;
310
311 hdrlen = sizeof(*guehdr) + optlen;
312
313 /* Adjust NAPI_GRO_CB(skb)->csum to account for guehdr,
314 * this is needed if there is a remote checkcsum offload.
315 */
316 skb_gro_postpull_rcsum(skb, guehdr, hdrlen);
317
318 data = &guehdr[1];
319
320 if (guehdr->flags & GUE_FLAG_PRIV) {
321 __be32 flags = *(__be32 *)(data + doffset);
322
323 doffset += GUE_LEN_PRIV;
324
325 if (flags & GUE_PFLAG_REMCSUM) {
326 guehdr = gue_gro_remcsum(skb, off, guehdr,
327 data + doffset, hdrlen, &grc,
328 !!(fou->flags &
329 FOU_F_REMCSUM_NOPARTIAL));
330
331 if (!guehdr)
332 goto out;
333
334 data = &guehdr[1];
335
336 doffset += GUE_PLEN_REMCSUM;
337 }
338 }
339
340 skb_gro_pull(skb, hdrlen);
341
342 for (p = *head; p; p = p->next) {
343 const struct guehdr *guehdr2;
344
345 if (!NAPI_GRO_CB(p)->same_flow)
346 continue;
347
348 guehdr2 = (struct guehdr *)(p->data + off);
349
350 /* Compare base GUE header to be equal (covers
351 * hlen, version, proto_ctype, and flags.
352 */
353 if (guehdr->word != guehdr2->word) {
354 NAPI_GRO_CB(p)->same_flow = 0;
355 continue;
356 }
357
358 /* Compare optional fields are the same. */
359 if (guehdr->hlen && memcmp(&guehdr[1], &guehdr2[1],
360 guehdr->hlen << 2)) {
361 NAPI_GRO_CB(p)->same_flow = 0;
362 continue;
363 }
364 }
365
366 /* We can clear the encap_mark for GUE as we are essentially doing
367 * one of two possible things. We are either adding an L4 tunnel
368 * header to the outer L3 tunnel header, or we are are simply
369 * treating the GRE tunnel header as though it is a UDP protocol
370 * specific header such as VXLAN or GENEVE.
371 */
372 NAPI_GRO_CB(skb)->encap_mark = 0;
373
374 /* Flag this frame as already having an outer encap header */
375 NAPI_GRO_CB(skb)->is_fou = 1;
376
377 rcu_read_lock();
378 offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads;
379 ops = rcu_dereference(offloads[guehdr->proto_ctype]);
380 if (WARN_ON_ONCE(!ops || !ops->callbacks.gro_receive))
381 goto out_unlock;
382
383 pp = ops->callbacks.gro_receive(head, skb);
384 flush = 0;
385
386out_unlock:
387 rcu_read_unlock();
388out:
389 NAPI_GRO_CB(skb)->flush |= flush;
390 skb_gro_remcsum_cleanup(skb, &grc);
391
392 return pp;
393}
394
395static int gue_gro_complete(struct sk_buff *skb, int nhoff,
396 struct udp_offload *uoff)
397{
398 const struct net_offload **offloads;
399 struct guehdr *guehdr = (struct guehdr *)(skb->data + nhoff);
400 const struct net_offload *ops;
401 unsigned int guehlen;
402 u8 proto;
403 int err = -ENOENT;
404
405 proto = guehdr->proto_ctype;
406
407 guehlen = sizeof(*guehdr) + (guehdr->hlen << 2);
408
409 rcu_read_lock();
410 offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads;
411 ops = rcu_dereference(offloads[proto]);
412 if (WARN_ON(!ops || !ops->callbacks.gro_complete))
413 goto out_unlock;
414
415 err = ops->callbacks.gro_complete(skb, nhoff + guehlen);
416
417 skb_set_inner_mac_header(skb, nhoff + guehlen);
418
419out_unlock:
420 rcu_read_unlock();
421 return err;
422}
423
424static int fou_add_to_port_list(struct net *net, struct fou *fou)
425{
426 struct fou_net *fn = net_generic(net, fou_net_id);
427 struct fou *fout;
428
429 mutex_lock(&fn->fou_lock);
430 list_for_each_entry(fout, &fn->fou_list, list) {
431 if (fou->port == fout->port) {
432 mutex_unlock(&fn->fou_lock);
433 return -EALREADY;
434 }
435 }
436
437 list_add(&fou->list, &fn->fou_list);
438 mutex_unlock(&fn->fou_lock);
439
440 return 0;
441}
442
443static void fou_release(struct fou *fou)
444{
445 struct socket *sock = fou->sock;
446 struct sock *sk = sock->sk;
447
448 if (sk->sk_family == AF_INET)
449 udp_del_offload(&fou->udp_offloads);
450 list_del(&fou->list);
451 udp_tunnel_sock_release(sock);
452
453 kfree_rcu(fou, rcu);
454}
455
456static int fou_encap_init(struct sock *sk, struct fou *fou, struct fou_cfg *cfg)
457{
458 udp_sk(sk)->encap_rcv = fou_udp_recv;
459 fou->protocol = cfg->protocol;
460 fou->udp_offloads.callbacks.gro_receive = fou_gro_receive;
461 fou->udp_offloads.callbacks.gro_complete = fou_gro_complete;
462 fou->udp_offloads.port = cfg->udp_config.local_udp_port;
463 fou->udp_offloads.ipproto = cfg->protocol;
464
465 return 0;
466}
467
468static int gue_encap_init(struct sock *sk, struct fou *fou, struct fou_cfg *cfg)
469{
470 udp_sk(sk)->encap_rcv = gue_udp_recv;
471 fou->udp_offloads.callbacks.gro_receive = gue_gro_receive;
472 fou->udp_offloads.callbacks.gro_complete = gue_gro_complete;
473 fou->udp_offloads.port = cfg->udp_config.local_udp_port;
474
475 return 0;
476}
477
478static int fou_create(struct net *net, struct fou_cfg *cfg,
479 struct socket **sockp)
480{
481 struct socket *sock = NULL;
482 struct fou *fou = NULL;
483 struct sock *sk;
484 int err;
485
486 /* Open UDP socket */
487 err = udp_sock_create(net, &cfg->udp_config, &sock);
488 if (err < 0)
489 goto error;
490
491 /* Allocate FOU port structure */
492 fou = kzalloc(sizeof(*fou), GFP_KERNEL);
493 if (!fou) {
494 err = -ENOMEM;
495 goto error;
496 }
497
498 sk = sock->sk;
499
500 fou->flags = cfg->flags;
501 fou->port = cfg->udp_config.local_udp_port;
502
503 /* Initial for fou type */
504 switch (cfg->type) {
505 case FOU_ENCAP_DIRECT:
506 err = fou_encap_init(sk, fou, cfg);
507 if (err)
508 goto error;
509 break;
510 case FOU_ENCAP_GUE:
511 err = gue_encap_init(sk, fou, cfg);
512 if (err)
513 goto error;
514 break;
515 default:
516 err = -EINVAL;
517 goto error;
518 }
519
520 fou->type = cfg->type;
521
522 udp_sk(sk)->encap_type = 1;
523 udp_encap_enable();
524
525 sk->sk_user_data = fou;
526 fou->sock = sock;
527
528 inet_inc_convert_csum(sk);
529
530 sk->sk_allocation = GFP_ATOMIC;
531
532 if (cfg->udp_config.family == AF_INET) {
533 err = udp_add_offload(net, &fou->udp_offloads);
534 if (err)
535 goto error;
536 }
537
538 err = fou_add_to_port_list(net, fou);
539 if (err)
540 goto error;
541
542 if (sockp)
543 *sockp = sock;
544
545 return 0;
546
547error:
548 kfree(fou);
549 if (sock)
550 udp_tunnel_sock_release(sock);
551
552 return err;
553}
554
555static int fou_destroy(struct net *net, struct fou_cfg *cfg)
556{
557 struct fou_net *fn = net_generic(net, fou_net_id);
558 __be16 port = cfg->udp_config.local_udp_port;
559 int err = -EINVAL;
560 struct fou *fou;
561
562 mutex_lock(&fn->fou_lock);
563 list_for_each_entry(fou, &fn->fou_list, list) {
564 if (fou->port == port) {
565 fou_release(fou);
566 err = 0;
567 break;
568 }
569 }
570 mutex_unlock(&fn->fou_lock);
571
572 return err;
573}
574
575static struct genl_family fou_nl_family = {
576 .id = GENL_ID_GENERATE,
577 .hdrsize = 0,
578 .name = FOU_GENL_NAME,
579 .version = FOU_GENL_VERSION,
580 .maxattr = FOU_ATTR_MAX,
581 .netnsok = true,
582};
583
584static struct nla_policy fou_nl_policy[FOU_ATTR_MAX + 1] = {
585 [FOU_ATTR_PORT] = { .type = NLA_U16, },
586 [FOU_ATTR_AF] = { .type = NLA_U8, },
587 [FOU_ATTR_IPPROTO] = { .type = NLA_U8, },
588 [FOU_ATTR_TYPE] = { .type = NLA_U8, },
589 [FOU_ATTR_REMCSUM_NOPARTIAL] = { .type = NLA_FLAG, },
590};
591
592static int parse_nl_config(struct genl_info *info,
593 struct fou_cfg *cfg)
594{
595 memset(cfg, 0, sizeof(*cfg));
596
597 cfg->udp_config.family = AF_INET;
598
599 if (info->attrs[FOU_ATTR_AF]) {
600 u8 family = nla_get_u8(info->attrs[FOU_ATTR_AF]);
601
602 if (family != AF_INET)
603 return -EINVAL;
604
605 cfg->udp_config.family = family;
606 }
607
608 if (info->attrs[FOU_ATTR_PORT]) {
609 __be16 port = nla_get_be16(info->attrs[FOU_ATTR_PORT]);
610
611 cfg->udp_config.local_udp_port = port;
612 }
613
614 if (info->attrs[FOU_ATTR_IPPROTO])
615 cfg->protocol = nla_get_u8(info->attrs[FOU_ATTR_IPPROTO]);
616
617 if (info->attrs[FOU_ATTR_TYPE])
618 cfg->type = nla_get_u8(info->attrs[FOU_ATTR_TYPE]);
619
620 if (info->attrs[FOU_ATTR_REMCSUM_NOPARTIAL])
621 cfg->flags |= FOU_F_REMCSUM_NOPARTIAL;
622
623 return 0;
624}
625
626static int fou_nl_cmd_add_port(struct sk_buff *skb, struct genl_info *info)
627{
628 struct net *net = genl_info_net(info);
629 struct fou_cfg cfg;
630 int err;
631
632 err = parse_nl_config(info, &cfg);
633 if (err)
634 return err;
635
636 return fou_create(net, &cfg, NULL);
637}
638
639static int fou_nl_cmd_rm_port(struct sk_buff *skb, struct genl_info *info)
640{
641 struct net *net = genl_info_net(info);
642 struct fou_cfg cfg;
643 int err;
644
645 err = parse_nl_config(info, &cfg);
646 if (err)
647 return err;
648
649 return fou_destroy(net, &cfg);
650}
651
652static int fou_fill_info(struct fou *fou, struct sk_buff *msg)
653{
654 if (nla_put_u8(msg, FOU_ATTR_AF, fou->sock->sk->sk_family) ||
655 nla_put_be16(msg, FOU_ATTR_PORT, fou->port) ||
656 nla_put_u8(msg, FOU_ATTR_IPPROTO, fou->protocol) ||
657 nla_put_u8(msg, FOU_ATTR_TYPE, fou->type))
658 return -1;
659
660 if (fou->flags & FOU_F_REMCSUM_NOPARTIAL)
661 if (nla_put_flag(msg, FOU_ATTR_REMCSUM_NOPARTIAL))
662 return -1;
663 return 0;
664}
665
666static int fou_dump_info(struct fou *fou, u32 portid, u32 seq,
667 u32 flags, struct sk_buff *skb, u8 cmd)
668{
669 void *hdr;
670
671 hdr = genlmsg_put(skb, portid, seq, &fou_nl_family, flags, cmd);
672 if (!hdr)
673 return -ENOMEM;
674
675 if (fou_fill_info(fou, skb) < 0)
676 goto nla_put_failure;
677
678 genlmsg_end(skb, hdr);
679 return 0;
680
681nla_put_failure:
682 genlmsg_cancel(skb, hdr);
683 return -EMSGSIZE;
684}
685
686static int fou_nl_cmd_get_port(struct sk_buff *skb, struct genl_info *info)
687{
688 struct net *net = genl_info_net(info);
689 struct fou_net *fn = net_generic(net, fou_net_id);
690 struct sk_buff *msg;
691 struct fou_cfg cfg;
692 struct fou *fout;
693 __be16 port;
694 int ret;
695
696 ret = parse_nl_config(info, &cfg);
697 if (ret)
698 return ret;
699 port = cfg.udp_config.local_udp_port;
700 if (port == 0)
701 return -EINVAL;
702
703 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
704 if (!msg)
705 return -ENOMEM;
706
707 ret = -ESRCH;
708 mutex_lock(&fn->fou_lock);
709 list_for_each_entry(fout, &fn->fou_list, list) {
710 if (port == fout->port) {
711 ret = fou_dump_info(fout, info->snd_portid,
712 info->snd_seq, 0, msg,
713 info->genlhdr->cmd);
714 break;
715 }
716 }
717 mutex_unlock(&fn->fou_lock);
718 if (ret < 0)
719 goto out_free;
720
721 return genlmsg_reply(msg, info);
722
723out_free:
724 nlmsg_free(msg);
725 return ret;
726}
727
728static int fou_nl_dump(struct sk_buff *skb, struct netlink_callback *cb)
729{
730 struct net *net = sock_net(skb->sk);
731 struct fou_net *fn = net_generic(net, fou_net_id);
732 struct fou *fout;
733 int idx = 0, ret;
734
735 mutex_lock(&fn->fou_lock);
736 list_for_each_entry(fout, &fn->fou_list, list) {
737 if (idx++ < cb->args[0])
738 continue;
739 ret = fou_dump_info(fout, NETLINK_CB(cb->skb).portid,
740 cb->nlh->nlmsg_seq, NLM_F_MULTI,
741 skb, FOU_CMD_GET);
742 if (ret)
743 break;
744 }
745 mutex_unlock(&fn->fou_lock);
746
747 cb->args[0] = idx;
748 return skb->len;
749}
750
751static const struct genl_ops fou_nl_ops[] = {
752 {
753 .cmd = FOU_CMD_ADD,
754 .doit = fou_nl_cmd_add_port,
755 .policy = fou_nl_policy,
756 .flags = GENL_ADMIN_PERM,
757 },
758 {
759 .cmd = FOU_CMD_DEL,
760 .doit = fou_nl_cmd_rm_port,
761 .policy = fou_nl_policy,
762 .flags = GENL_ADMIN_PERM,
763 },
764 {
765 .cmd = FOU_CMD_GET,
766 .doit = fou_nl_cmd_get_port,
767 .dumpit = fou_nl_dump,
768 .policy = fou_nl_policy,
769 },
770};
771
772size_t fou_encap_hlen(struct ip_tunnel_encap *e)
773{
774 return sizeof(struct udphdr);
775}
776EXPORT_SYMBOL(fou_encap_hlen);
777
778size_t gue_encap_hlen(struct ip_tunnel_encap *e)
779{
780 size_t len;
781 bool need_priv = false;
782
783 len = sizeof(struct udphdr) + sizeof(struct guehdr);
784
785 if (e->flags & TUNNEL_ENCAP_FLAG_REMCSUM) {
786 len += GUE_PLEN_REMCSUM;
787 need_priv = true;
788 }
789
790 len += need_priv ? GUE_LEN_PRIV : 0;
791
792 return len;
793}
794EXPORT_SYMBOL(gue_encap_hlen);
795
796static void fou_build_udp(struct sk_buff *skb, struct ip_tunnel_encap *e,
797 struct flowi4 *fl4, u8 *protocol, __be16 sport)
798{
799 struct udphdr *uh;
800
801 skb_push(skb, sizeof(struct udphdr));
802 skb_reset_transport_header(skb);
803
804 uh = udp_hdr(skb);
805
806 uh->dest = e->dport;
807 uh->source = sport;
808 uh->len = htons(skb->len);
809 udp_set_csum(!(e->flags & TUNNEL_ENCAP_FLAG_CSUM), skb,
810 fl4->saddr, fl4->daddr, skb->len);
811
812 *protocol = IPPROTO_UDP;
813}
814
815int fou_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
816 u8 *protocol, struct flowi4 *fl4)
817{
818 int type = e->flags & TUNNEL_ENCAP_FLAG_CSUM ? SKB_GSO_UDP_TUNNEL_CSUM :
819 SKB_GSO_UDP_TUNNEL;
820 __be16 sport;
821
822 skb = iptunnel_handle_offloads(skb, type);
823
824 if (IS_ERR(skb))
825 return PTR_ERR(skb);
826
827 sport = e->sport ? : udp_flow_src_port(dev_net(skb->dev),
828 skb, 0, 0, false);
829 fou_build_udp(skb, e, fl4, protocol, sport);
830
831 return 0;
832}
833EXPORT_SYMBOL(fou_build_header);
834
835int gue_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
836 u8 *protocol, struct flowi4 *fl4)
837{
838 int type = e->flags & TUNNEL_ENCAP_FLAG_CSUM ? SKB_GSO_UDP_TUNNEL_CSUM :
839 SKB_GSO_UDP_TUNNEL;
840 struct guehdr *guehdr;
841 size_t hdrlen, optlen = 0;
842 __be16 sport;
843 void *data;
844 bool need_priv = false;
845
846 if ((e->flags & TUNNEL_ENCAP_FLAG_REMCSUM) &&
847 skb->ip_summed == CHECKSUM_PARTIAL) {
848 optlen += GUE_PLEN_REMCSUM;
849 type |= SKB_GSO_TUNNEL_REMCSUM;
850 need_priv = true;
851 }
852
853 optlen += need_priv ? GUE_LEN_PRIV : 0;
854
855 skb = iptunnel_handle_offloads(skb, type);
856
857 if (IS_ERR(skb))
858 return PTR_ERR(skb);
859
860 /* Get source port (based on flow hash) before skb_push */
861 sport = e->sport ? : udp_flow_src_port(dev_net(skb->dev),
862 skb, 0, 0, false);
863
864 hdrlen = sizeof(struct guehdr) + optlen;
865
866 skb_push(skb, hdrlen);
867
868 guehdr = (struct guehdr *)skb->data;
869
870 guehdr->control = 0;
871 guehdr->version = 0;
872 guehdr->hlen = optlen >> 2;
873 guehdr->flags = 0;
874 guehdr->proto_ctype = *protocol;
875
876 data = &guehdr[1];
877
878 if (need_priv) {
879 __be32 *flags = data;
880
881 guehdr->flags |= GUE_FLAG_PRIV;
882 *flags = 0;
883 data += GUE_LEN_PRIV;
884
885 if (type & SKB_GSO_TUNNEL_REMCSUM) {
886 u16 csum_start = skb_checksum_start_offset(skb);
887 __be16 *pd = data;
888
889 if (csum_start < hdrlen)
890 return -EINVAL;
891
892 csum_start -= hdrlen;
893 pd[0] = htons(csum_start);
894 pd[1] = htons(csum_start + skb->csum_offset);
895
896 if (!skb_is_gso(skb)) {
897 skb->ip_summed = CHECKSUM_NONE;
898 skb->encapsulation = 0;
899 }
900
901 *flags |= GUE_PFLAG_REMCSUM;
902 data += GUE_PLEN_REMCSUM;
903 }
904
905 }
906
907 fou_build_udp(skb, e, fl4, protocol, sport);
908
909 return 0;
910}
911EXPORT_SYMBOL(gue_build_header);
912
913#ifdef CONFIG_NET_FOU_IP_TUNNELS
914
915static const struct ip_tunnel_encap_ops fou_iptun_ops = {
916 .encap_hlen = fou_encap_hlen,
917 .build_header = fou_build_header,
918};
919
920static const struct ip_tunnel_encap_ops gue_iptun_ops = {
921 .encap_hlen = gue_encap_hlen,
922 .build_header = gue_build_header,
923};
924
925static int ip_tunnel_encap_add_fou_ops(void)
926{
927 int ret;
928
929 ret = ip_tunnel_encap_add_ops(&fou_iptun_ops, TUNNEL_ENCAP_FOU);
930 if (ret < 0) {
931 pr_err("can't add fou ops\n");
932 return ret;
933 }
934
935 ret = ip_tunnel_encap_add_ops(&gue_iptun_ops, TUNNEL_ENCAP_GUE);
936 if (ret < 0) {
937 pr_err("can't add gue ops\n");
938 ip_tunnel_encap_del_ops(&fou_iptun_ops, TUNNEL_ENCAP_FOU);
939 return ret;
940 }
941
942 return 0;
943}
944
945static void ip_tunnel_encap_del_fou_ops(void)
946{
947 ip_tunnel_encap_del_ops(&fou_iptun_ops, TUNNEL_ENCAP_FOU);
948 ip_tunnel_encap_del_ops(&gue_iptun_ops, TUNNEL_ENCAP_GUE);
949}
950
951#else
952
953static int ip_tunnel_encap_add_fou_ops(void)
954{
955 return 0;
956}
957
958static void ip_tunnel_encap_del_fou_ops(void)
959{
960}
961
962#endif
963
964static __net_init int fou_init_net(struct net *net)
965{
966 struct fou_net *fn = net_generic(net, fou_net_id);
967
968 INIT_LIST_HEAD(&fn->fou_list);
969 mutex_init(&fn->fou_lock);
970 return 0;
971}
972
973static __net_exit void fou_exit_net(struct net *net)
974{
975 struct fou_net *fn = net_generic(net, fou_net_id);
976 struct fou *fou, *next;
977
978 /* Close all the FOU sockets */
979 mutex_lock(&fn->fou_lock);
980 list_for_each_entry_safe(fou, next, &fn->fou_list, list)
981 fou_release(fou);
982 mutex_unlock(&fn->fou_lock);
983}
984
985static struct pernet_operations fou_net_ops = {
986 .init = fou_init_net,
987 .exit = fou_exit_net,
988 .id = &fou_net_id,
989 .size = sizeof(struct fou_net),
990};
991
992static int __init fou_init(void)
993{
994 int ret;
995
996 ret = register_pernet_device(&fou_net_ops);
997 if (ret)
998 goto exit;
999
1000 ret = genl_register_family_with_ops(&fou_nl_family,
1001 fou_nl_ops);
1002 if (ret < 0)
1003 goto unregister;
1004
1005 ret = ip_tunnel_encap_add_fou_ops();
1006 if (ret == 0)
1007 return 0;
1008
1009 genl_unregister_family(&fou_nl_family);
1010unregister:
1011 unregister_pernet_device(&fou_net_ops);
1012exit:
1013 return ret;
1014}
1015
1016static void __exit fou_fini(void)
1017{
1018 ip_tunnel_encap_del_fou_ops();
1019 genl_unregister_family(&fou_nl_family);
1020 unregister_pernet_device(&fou_net_ops);
1021}
1022
1023module_init(fou_init);
1024module_exit(fou_fini);
1025MODULE_AUTHOR("Tom Herbert <therbert@google.com>");
1026MODULE_LICENSE("GPL");