xref: /openbmc/linux/net/ipv6/seg6_local.c (revision 711aab1d) 
1 /*
2  *  SR-IPv6 implementation
3  *
4  *  Author:
5  *  David Lebrun <david.lebrun@uclouvain.be>
6  *
7  *
8  *  This program is free software; you can redistribute it and/or
9  *        modify it under the terms of the GNU General Public License
10  *        as published by the Free Software Foundation; either version
11  *        2 of the License, or (at your option) any later version.
12  */
13 
14 #include <linux/types.h>
15 #include <linux/skbuff.h>
16 #include <linux/net.h>
17 #include <linux/module.h>
18 #include <net/ip.h>
19 #include <net/lwtunnel.h>
20 #include <net/netevent.h>
21 #include <net/netns/generic.h>
22 #include <net/ip6_fib.h>
23 #include <net/route.h>
24 #include <net/seg6.h>
25 #include <linux/seg6.h>
26 #include <linux/seg6_local.h>
27 #include <net/addrconf.h>
28 #include <net/ip6_route.h>
29 #include <net/dst_cache.h>
30 #ifdef CONFIG_IPV6_SEG6_HMAC
31 #include <net/seg6_hmac.h>
32 #endif
33 #include <linux/etherdevice.h>
34 
35 struct seg6_local_lwt;
36 
37 struct seg6_action_desc {
38 	int action;
39 	unsigned long attrs;
40 	int (*input)(struct sk_buff *skb, struct seg6_local_lwt *slwt);
41 	int static_headroom;
42 };
43 
44 struct seg6_local_lwt {
45 	int action;
46 	struct ipv6_sr_hdr *srh;
47 	int table;
48 	struct in_addr nh4;
49 	struct in6_addr nh6;
50 	int iif;
51 	int oif;
52 
53 	int headroom;
54 	struct seg6_action_desc *desc;
55 };
56 
57 static struct seg6_local_lwt *seg6_local_lwtunnel(struct lwtunnel_state *lwt)
58 {
59 	return (struct seg6_local_lwt *)lwt->data;
60 }
61 
62 static struct ipv6_sr_hdr *get_srh(struct sk_buff *skb)
63 {
64 	struct ipv6_sr_hdr *srh;
65 	int len, srhoff = 0;
66 
67 	if (ipv6_find_hdr(skb, &srhoff, IPPROTO_ROUTING, NULL, NULL) < 0)
68 		return NULL;
69 
70 	if (!pskb_may_pull(skb, srhoff + sizeof(*srh)))
71 		return NULL;
72 
73 	srh = (struct ipv6_sr_hdr *)(skb->data + srhoff);
74 
75 	/* make sure it's a Segment Routing header (Routing Type 4) */
76 	if (srh->type != IPV6_SRCRT_TYPE_4)
77 		return NULL;
78 
79 	len = (srh->hdrlen + 1) << 3;
80 
81 	if (!pskb_may_pull(skb, srhoff + len))
82 		return NULL;
83 
84 	if (!seg6_validate_srh(srh, len))
85 		return NULL;
86 
87 	return srh;
88 }
89 
90 static struct ipv6_sr_hdr *get_and_validate_srh(struct sk_buff *skb)
91 {
92 	struct ipv6_sr_hdr *srh;
93 
94 	srh = get_srh(skb);
95 	if (!srh)
96 		return NULL;
97 
98 	if (srh->segments_left == 0)
99 		return NULL;
100 
101 #ifdef CONFIG_IPV6_SEG6_HMAC
102 	if (!seg6_hmac_validate_skb(skb))
103 		return NULL;
104 #endif
105 
106 	return srh;
107 }
108 
109 static bool decap_and_validate(struct sk_buff *skb, int proto)
110 {
111 	struct ipv6_sr_hdr *srh;
112 	unsigned int off = 0;
113 
114 	srh = get_srh(skb);
115 	if (srh && srh->segments_left > 0)
116 		return false;
117 
118 #ifdef CONFIG_IPV6_SEG6_HMAC
119 	if (srh && !seg6_hmac_validate_skb(skb))
120 		return false;
121 #endif
122 
123 	if (ipv6_find_hdr(skb, &off, proto, NULL, NULL) < 0)
124 		return false;
125 
126 	if (!pskb_pull(skb, off))
127 		return false;
128 
129 	skb_postpull_rcsum(skb, skb_network_header(skb), off);
130 
131 	skb_reset_network_header(skb);
132 	skb_reset_transport_header(skb);
133 	skb->encapsulation = 0;
134 
135 	return true;
136 }
137 
138 static void advance_nextseg(struct ipv6_sr_hdr *srh, struct in6_addr *daddr)
139 {
140 	struct in6_addr *addr;
141 
142 	srh->segments_left--;
143 	addr = srh->segments + srh->segments_left;
144 	*daddr = *addr;
145 }
146 
147 static void lookup_nexthop(struct sk_buff *skb, struct in6_addr *nhaddr,
148 			   u32 tbl_id)
149 {
150 	struct net *net = dev_net(skb->dev);
151 	struct ipv6hdr *hdr = ipv6_hdr(skb);
152 	int flags = RT6_LOOKUP_F_HAS_SADDR;
153 	struct dst_entry *dst = NULL;
154 	struct rt6_info *rt;
155 	struct flowi6 fl6;
156 
157 	fl6.flowi6_iif = skb->dev->ifindex;
158 	fl6.daddr = nhaddr ? *nhaddr : hdr->daddr;
159 	fl6.saddr = hdr->saddr;
160 	fl6.flowlabel = ip6_flowinfo(hdr);
161 	fl6.flowi6_mark = skb->mark;
162 	fl6.flowi6_proto = hdr->nexthdr;
163 
164 	if (nhaddr)
165 		fl6.flowi6_flags = FLOWI_FLAG_KNOWN_NH;
166 
167 	if (!tbl_id) {
168 		dst = ip6_route_input_lookup(net, skb->dev, &fl6, flags);
169 	} else {
170 		struct fib6_table *table;
171 
172 		table = fib6_get_table(net, tbl_id);
173 		if (!table)
174 			goto out;
175 
176 		rt = ip6_pol_route(net, table, 0, &fl6, flags);
177 		dst = &rt->dst;
178 	}
179 
180 	if (dst && dst->dev->flags & IFF_LOOPBACK && !dst->error) {
181 		dst_release(dst);
182 		dst = NULL;
183 	}
184 
185 out:
186 	if (!dst) {
187 		rt = net->ipv6.ip6_blk_hole_entry;
188 		dst = &rt->dst;
189 		dst_hold(dst);
190 	}
191 
192 	skb_dst_drop(skb);
193 	skb_dst_set(skb, dst);
194 }
195 
196 /* regular endpoint function */
197 static int input_action_end(struct sk_buff *skb, struct seg6_local_lwt *slwt)
198 {
199 	struct ipv6_sr_hdr *srh;
200 
201 	srh = get_and_validate_srh(skb);
202 	if (!srh)
203 		goto drop;
204 
205 	advance_nextseg(srh, &ipv6_hdr(skb)->daddr);
206 
207 	lookup_nexthop(skb, NULL, 0);
208 
209 	return dst_input(skb);
210 
211 drop:
212 	kfree_skb(skb);
213 	return -EINVAL;
214 }
215 
216 /* regular endpoint, and forward to specified nexthop */
217 static int input_action_end_x(struct sk_buff *skb, struct seg6_local_lwt *slwt)
218 {
219 	struct ipv6_sr_hdr *srh;
220 
221 	srh = get_and_validate_srh(skb);
222 	if (!srh)
223 		goto drop;
224 
225 	advance_nextseg(srh, &ipv6_hdr(skb)->daddr);
226 
227 	lookup_nexthop(skb, &slwt->nh6, 0);
228 
229 	return dst_input(skb);
230 
231 drop:
232 	kfree_skb(skb);
233 	return -EINVAL;
234 }
235 
236 static int input_action_end_t(struct sk_buff *skb, struct seg6_local_lwt *slwt)
237 {
238 	struct ipv6_sr_hdr *srh;
239 
240 	srh = get_and_validate_srh(skb);
241 	if (!srh)
242 		goto drop;
243 
244 	advance_nextseg(srh, &ipv6_hdr(skb)->daddr);
245 
246 	lookup_nexthop(skb, NULL, slwt->table);
247 
248 	return dst_input(skb);
249 
250 drop:
251 	kfree_skb(skb);
252 	return -EINVAL;
253 }
254 
255 /* decapsulate and forward inner L2 frame on specified interface */
256 static int input_action_end_dx2(struct sk_buff *skb,
257 				struct seg6_local_lwt *slwt)
258 {
259 	struct net *net = dev_net(skb->dev);
260 	struct net_device *odev;
261 	struct ethhdr *eth;
262 
263 	if (!decap_and_validate(skb, NEXTHDR_NONE))
264 		goto drop;
265 
266 	if (!pskb_may_pull(skb, ETH_HLEN))
267 		goto drop;
268 
269 	skb_reset_mac_header(skb);
270 	eth = (struct ethhdr *)skb->data;
271 
272 	/* To determine the frame's protocol, we assume it is 802.3. This avoids
273 	 * a call to eth_type_trans(), which is not really relevant for our
274 	 * use case.
275 	 */
276 	if (!eth_proto_is_802_3(eth->h_proto))
277 		goto drop;
278 
279 	odev = dev_get_by_index_rcu(net, slwt->oif);
280 	if (!odev)
281 		goto drop;
282 
283 	/* As we accept Ethernet frames, make sure the egress device is of
284 	 * the correct type.
285 	 */
286 	if (odev->type != ARPHRD_ETHER)
287 		goto drop;
288 
289 	if (!(odev->flags & IFF_UP) || !netif_carrier_ok(odev))
290 		goto drop;
291 
292 	skb_orphan(skb);
293 
294 	if (skb_warn_if_lro(skb))
295 		goto drop;
296 
297 	skb_forward_csum(skb);
298 
299 	if (skb->len - ETH_HLEN > odev->mtu)
300 		goto drop;
301 
302 	skb->dev = odev;
303 	skb->protocol = eth->h_proto;
304 
305 	return dev_queue_xmit(skb);
306 
307 drop:
308 	kfree_skb(skb);
309 	return -EINVAL;
310 }
311 
312 /* decapsulate and forward to specified nexthop */
313 static int input_action_end_dx6(struct sk_buff *skb,
314 				struct seg6_local_lwt *slwt)
315 {
316 	struct in6_addr *nhaddr = NULL;
317 
318 	/* this function accepts IPv6 encapsulated packets, with either
319 	 * an SRH with SL=0, or no SRH.
320 	 */
321 
322 	if (!decap_and_validate(skb, IPPROTO_IPV6))
323 		goto drop;
324 
325 	if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
326 		goto drop;
327 
328 	/* The inner packet is not associated to any local interface,
329 	 * so we do not call netif_rx().
330 	 *
331 	 * If slwt->nh6 is set to ::, then lookup the nexthop for the
332 	 * inner packet's DA. Otherwise, use the specified nexthop.
333 	 */
334 
335 	if (!ipv6_addr_any(&slwt->nh6))
336 		nhaddr = &slwt->nh6;
337 
338 	lookup_nexthop(skb, nhaddr, 0);
339 
340 	return dst_input(skb);
341 drop:
342 	kfree_skb(skb);
343 	return -EINVAL;
344 }
345 
346 static int input_action_end_dx4(struct sk_buff *skb,
347 				struct seg6_local_lwt *slwt)
348 {
349 	struct iphdr *iph;
350 	__be32 nhaddr;
351 	int err;
352 
353 	if (!decap_and_validate(skb, IPPROTO_IPIP))
354 		goto drop;
355 
356 	if (!pskb_may_pull(skb, sizeof(struct iphdr)))
357 		goto drop;
358 
359 	skb->protocol = htons(ETH_P_IP);
360 
361 	iph = ip_hdr(skb);
362 
363 	nhaddr = slwt->nh4.s_addr ?: iph->daddr;
364 
365 	skb_dst_drop(skb);
366 
367 	err = ip_route_input(skb, nhaddr, iph->saddr, 0, skb->dev);
368 	if (err)
369 		goto drop;
370 
371 	return dst_input(skb);
372 
373 drop:
374 	kfree_skb(skb);
375 	return -EINVAL;
376 }
377 
378 static int input_action_end_dt6(struct sk_buff *skb,
379 				struct seg6_local_lwt *slwt)
380 {
381 	if (!decap_and_validate(skb, IPPROTO_IPV6))
382 		goto drop;
383 
384 	if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
385 		goto drop;
386 
387 	lookup_nexthop(skb, NULL, slwt->table);
388 
389 	return dst_input(skb);
390 
391 drop:
392 	kfree_skb(skb);
393 	return -EINVAL;
394 }
395 
396 /* push an SRH on top of the current one */
397 static int input_action_end_b6(struct sk_buff *skb, struct seg6_local_lwt *slwt)
398 {
399 	struct ipv6_sr_hdr *srh;
400 	int err = -EINVAL;
401 
402 	srh = get_and_validate_srh(skb);
403 	if (!srh)
404 		goto drop;
405 
406 	err = seg6_do_srh_inline(skb, slwt->srh);
407 	if (err)
408 		goto drop;
409 
410 	ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
411 	skb_set_transport_header(skb, sizeof(struct ipv6hdr));
412 
413 	lookup_nexthop(skb, NULL, 0);
414 
415 	return dst_input(skb);
416 
417 drop:
418 	kfree_skb(skb);
419 	return err;
420 }
421 
422 /* encapsulate within an outer IPv6 header and a specified SRH */
423 static int input_action_end_b6_encap(struct sk_buff *skb,
424 				     struct seg6_local_lwt *slwt)
425 {
426 	struct ipv6_sr_hdr *srh;
427 	int err = -EINVAL;
428 
429 	srh = get_and_validate_srh(skb);
430 	if (!srh)
431 		goto drop;
432 
433 	advance_nextseg(srh, &ipv6_hdr(skb)->daddr);
434 
435 	skb_reset_inner_headers(skb);
436 	skb->encapsulation = 1;
437 
438 	err = seg6_do_srh_encap(skb, slwt->srh, IPPROTO_IPV6);
439 	if (err)
440 		goto drop;
441 
442 	ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
443 	skb_set_transport_header(skb, sizeof(struct ipv6hdr));
444 
445 	lookup_nexthop(skb, NULL, 0);
446 
447 	return dst_input(skb);
448 
449 drop:
450 	kfree_skb(skb);
451 	return err;
452 }
453 
454 static struct seg6_action_desc seg6_action_table[] = {
455 	{
456 		.action		= SEG6_LOCAL_ACTION_END,
457 		.attrs		= 0,
458 		.input		= input_action_end,
459 	},
460 	{
461 		.action		= SEG6_LOCAL_ACTION_END_X,
462 		.attrs		= (1 << SEG6_LOCAL_NH6),
463 		.input		= input_action_end_x,
464 	},
465 	{
466 		.action		= SEG6_LOCAL_ACTION_END_T,
467 		.attrs		= (1 << SEG6_LOCAL_TABLE),
468 		.input		= input_action_end_t,
469 	},
470 	{
471 		.action		= SEG6_LOCAL_ACTION_END_DX2,
472 		.attrs		= (1 << SEG6_LOCAL_OIF),
473 		.input		= input_action_end_dx2,
474 	},
475 	{
476 		.action		= SEG6_LOCAL_ACTION_END_DX6,
477 		.attrs		= (1 << SEG6_LOCAL_NH6),
478 		.input		= input_action_end_dx6,
479 	},
480 	{
481 		.action		= SEG6_LOCAL_ACTION_END_DX4,
482 		.attrs		= (1 << SEG6_LOCAL_NH4),
483 		.input		= input_action_end_dx4,
484 	},
485 	{
486 		.action		= SEG6_LOCAL_ACTION_END_DT6,
487 		.attrs		= (1 << SEG6_LOCAL_TABLE),
488 		.input		= input_action_end_dt6,
489 	},
490 	{
491 		.action		= SEG6_LOCAL_ACTION_END_B6,
492 		.attrs		= (1 << SEG6_LOCAL_SRH),
493 		.input		= input_action_end_b6,
494 	},
495 	{
496 		.action		= SEG6_LOCAL_ACTION_END_B6_ENCAP,
497 		.attrs		= (1 << SEG6_LOCAL_SRH),
498 		.input		= input_action_end_b6_encap,
499 		.static_headroom	= sizeof(struct ipv6hdr),
500 	}
501 };
502 
503 static struct seg6_action_desc *__get_action_desc(int action)
504 {
505 	struct seg6_action_desc *desc;
506 	int i, count;
507 
508 	count = sizeof(seg6_action_table) / sizeof(struct seg6_action_desc);
509 	for (i = 0; i < count; i++) {
510 		desc = &seg6_action_table[i];
511 		if (desc->action == action)
512 			return desc;
513 	}
514 
515 	return NULL;
516 }
517 
518 static int seg6_local_input(struct sk_buff *skb)
519 {
520 	struct dst_entry *orig_dst = skb_dst(skb);
521 	struct seg6_action_desc *desc;
522 	struct seg6_local_lwt *slwt;
523 
524 	if (skb->protocol != htons(ETH_P_IPV6)) {
525 		kfree_skb(skb);
526 		return -EINVAL;
527 	}
528 
529 	slwt = seg6_local_lwtunnel(orig_dst->lwtstate);
530 	desc = slwt->desc;
531 
532 	return desc->input(skb, slwt);
533 }
534 
535 static const struct nla_policy seg6_local_policy[SEG6_LOCAL_MAX + 1] = {
536 	[SEG6_LOCAL_ACTION]	= { .type = NLA_U32 },
537 	[SEG6_LOCAL_SRH]	= { .type = NLA_BINARY },
538 	[SEG6_LOCAL_TABLE]	= { .type = NLA_U32 },
539 	[SEG6_LOCAL_NH4]	= { .type = NLA_BINARY,
540 				    .len = sizeof(struct in_addr) },
541 	[SEG6_LOCAL_NH6]	= { .type = NLA_BINARY,
542 				    .len = sizeof(struct in6_addr) },
543 	[SEG6_LOCAL_IIF]	= { .type = NLA_U32 },
544 	[SEG6_LOCAL_OIF]	= { .type = NLA_U32 },
545 };
546 
547 static int parse_nla_srh(struct nlattr **attrs, struct seg6_local_lwt *slwt)
548 {
549 	struct ipv6_sr_hdr *srh;
550 	int len;
551 
552 	srh = nla_data(attrs[SEG6_LOCAL_SRH]);
553 	len = nla_len(attrs[SEG6_LOCAL_SRH]);
554 
555 	/* SRH must contain at least one segment */
556 	if (len < sizeof(*srh) + sizeof(struct in6_addr))
557 		return -EINVAL;
558 
559 	if (!seg6_validate_srh(srh, len))
560 		return -EINVAL;
561 
562 	slwt->srh = kmalloc(len, GFP_KERNEL);
563 	if (!slwt->srh)
564 		return -ENOMEM;
565 
566 	memcpy(slwt->srh, srh, len);
567 
568 	slwt->headroom += len;
569 
570 	return 0;
571 }
572 
573 static int put_nla_srh(struct sk_buff *skb, struct seg6_local_lwt *slwt)
574 {
575 	struct ipv6_sr_hdr *srh;
576 	struct nlattr *nla;
577 	int len;
578 
579 	srh = slwt->srh;
580 	len = (srh->hdrlen + 1) << 3;
581 
582 	nla = nla_reserve(skb, SEG6_LOCAL_SRH, len);
583 	if (!nla)
584 		return -EMSGSIZE;
585 
586 	memcpy(nla_data(nla), srh, len);
587 
588 	return 0;
589 }
590 
591 static int cmp_nla_srh(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
592 {
593 	int len = (a->srh->hdrlen + 1) << 3;
594 
595 	if (len != ((b->srh->hdrlen + 1) << 3))
596 		return 1;
597 
598 	return memcmp(a->srh, b->srh, len);
599 }
600 
601 static int parse_nla_table(struct nlattr **attrs, struct seg6_local_lwt *slwt)
602 {
603 	slwt->table = nla_get_u32(attrs[SEG6_LOCAL_TABLE]);
604 
605 	return 0;
606 }
607 
608 static int put_nla_table(struct sk_buff *skb, struct seg6_local_lwt *slwt)
609 {
610 	if (nla_put_u32(skb, SEG6_LOCAL_TABLE, slwt->table))
611 		return -EMSGSIZE;
612 
613 	return 0;
614 }
615 
616 static int cmp_nla_table(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
617 {
618 	if (a->table != b->table)
619 		return 1;
620 
621 	return 0;
622 }
623 
624 static int parse_nla_nh4(struct nlattr **attrs, struct seg6_local_lwt *slwt)
625 {
626 	memcpy(&slwt->nh4, nla_data(attrs[SEG6_LOCAL_NH4]),
627 	       sizeof(struct in_addr));
628 
629 	return 0;
630 }
631 
632 static int put_nla_nh4(struct sk_buff *skb, struct seg6_local_lwt *slwt)
633 {
634 	struct nlattr *nla;
635 
636 	nla = nla_reserve(skb, SEG6_LOCAL_NH4, sizeof(struct in_addr));
637 	if (!nla)
638 		return -EMSGSIZE;
639 
640 	memcpy(nla_data(nla), &slwt->nh4, sizeof(struct in_addr));
641 
642 	return 0;
643 }
644 
645 static int cmp_nla_nh4(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
646 {
647 	return memcmp(&a->nh4, &b->nh4, sizeof(struct in_addr));
648 }
649 
650 static int parse_nla_nh6(struct nlattr **attrs, struct seg6_local_lwt *slwt)
651 {
652 	memcpy(&slwt->nh6, nla_data(attrs[SEG6_LOCAL_NH6]),
653 	       sizeof(struct in6_addr));
654 
655 	return 0;
656 }
657 
658 static int put_nla_nh6(struct sk_buff *skb, struct seg6_local_lwt *slwt)
659 {
660 	struct nlattr *nla;
661 
662 	nla = nla_reserve(skb, SEG6_LOCAL_NH6, sizeof(struct in6_addr));
663 	if (!nla)
664 		return -EMSGSIZE;
665 
666 	memcpy(nla_data(nla), &slwt->nh6, sizeof(struct in6_addr));
667 
668 	return 0;
669 }
670 
671 static int cmp_nla_nh6(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
672 {
673 	return memcmp(&a->nh6, &b->nh6, sizeof(struct in6_addr));
674 }
675 
676 static int parse_nla_iif(struct nlattr **attrs, struct seg6_local_lwt *slwt)
677 {
678 	slwt->iif = nla_get_u32(attrs[SEG6_LOCAL_IIF]);
679 
680 	return 0;
681 }
682 
683 static int put_nla_iif(struct sk_buff *skb, struct seg6_local_lwt *slwt)
684 {
685 	if (nla_put_u32(skb, SEG6_LOCAL_IIF, slwt->iif))
686 		return -EMSGSIZE;
687 
688 	return 0;
689 }
690 
691 static int cmp_nla_iif(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
692 {
693 	if (a->iif != b->iif)
694 		return 1;
695 
696 	return 0;
697 }
698 
699 static int parse_nla_oif(struct nlattr **attrs, struct seg6_local_lwt *slwt)
700 {
701 	slwt->oif = nla_get_u32(attrs[SEG6_LOCAL_OIF]);
702 
703 	return 0;
704 }
705 
706 static int put_nla_oif(struct sk_buff *skb, struct seg6_local_lwt *slwt)
707 {
708 	if (nla_put_u32(skb, SEG6_LOCAL_OIF, slwt->oif))
709 		return -EMSGSIZE;
710 
711 	return 0;
712 }
713 
714 static int cmp_nla_oif(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
715 {
716 	if (a->oif != b->oif)
717 		return 1;
718 
719 	return 0;
720 }
721 
722 struct seg6_action_param {
723 	int (*parse)(struct nlattr **attrs, struct seg6_local_lwt *slwt);
724 	int (*put)(struct sk_buff *skb, struct seg6_local_lwt *slwt);
725 	int (*cmp)(struct seg6_local_lwt *a, struct seg6_local_lwt *b);
726 };
727 
728 static struct seg6_action_param seg6_action_params[SEG6_LOCAL_MAX + 1] = {
729 	[SEG6_LOCAL_SRH]	= { .parse = parse_nla_srh,
730 				    .put = put_nla_srh,
731 				    .cmp = cmp_nla_srh },
732 
733 	[SEG6_LOCAL_TABLE]	= { .parse = parse_nla_table,
734 				    .put = put_nla_table,
735 				    .cmp = cmp_nla_table },
736 
737 	[SEG6_LOCAL_NH4]	= { .parse = parse_nla_nh4,
738 				    .put = put_nla_nh4,
739 				    .cmp = cmp_nla_nh4 },
740 
741 	[SEG6_LOCAL_NH6]	= { .parse = parse_nla_nh6,
742 				    .put = put_nla_nh6,
743 				    .cmp = cmp_nla_nh6 },
744 
745 	[SEG6_LOCAL_IIF]	= { .parse = parse_nla_iif,
746 				    .put = put_nla_iif,
747 				    .cmp = cmp_nla_iif },
748 
749 	[SEG6_LOCAL_OIF]	= { .parse = parse_nla_oif,
750 				    .put = put_nla_oif,
751 				    .cmp = cmp_nla_oif },
752 };
753 
754 static int parse_nla_action(struct nlattr **attrs, struct seg6_local_lwt *slwt)
755 {
756 	struct seg6_action_param *param;
757 	struct seg6_action_desc *desc;
758 	int i, err;
759 
760 	desc = __get_action_desc(slwt->action);
761 	if (!desc)
762 		return -EINVAL;
763 
764 	if (!desc->input)
765 		return -EOPNOTSUPP;
766 
767 	slwt->desc = desc;
768 	slwt->headroom += desc->static_headroom;
769 
770 	for (i = 0; i < SEG6_LOCAL_MAX + 1; i++) {
771 		if (desc->attrs & (1 << i)) {
772 			if (!attrs[i])
773 				return -EINVAL;
774 
775 			param = &seg6_action_params[i];
776 
777 			err = param->parse(attrs, slwt);
778 			if (err < 0)
779 				return err;
780 		}
781 	}
782 
783 	return 0;
784 }
785 
786 static int seg6_local_build_state(struct nlattr *nla, unsigned int family,
787 				  const void *cfg, struct lwtunnel_state **ts,
788 				  struct netlink_ext_ack *extack)
789 {
790 	struct nlattr *tb[SEG6_LOCAL_MAX + 1];
791 	struct lwtunnel_state *newts;
792 	struct seg6_local_lwt *slwt;
793 	int err;
794 
795 	if (family != AF_INET6)
796 		return -EINVAL;
797 
798 	err = nla_parse_nested(tb, SEG6_LOCAL_MAX, nla, seg6_local_policy,
799 			       extack);
800 
801 	if (err < 0)
802 		return err;
803 
804 	if (!tb[SEG6_LOCAL_ACTION])
805 		return -EINVAL;
806 
807 	newts = lwtunnel_state_alloc(sizeof(*slwt));
808 	if (!newts)
809 		return -ENOMEM;
810 
811 	slwt = seg6_local_lwtunnel(newts);
812 	slwt->action = nla_get_u32(tb[SEG6_LOCAL_ACTION]);
813 
814 	err = parse_nla_action(tb, slwt);
815 	if (err < 0)
816 		goto out_free;
817 
818 	newts->type = LWTUNNEL_ENCAP_SEG6_LOCAL;
819 	newts->flags = LWTUNNEL_STATE_INPUT_REDIRECT;
820 	newts->headroom = slwt->headroom;
821 
822 	*ts = newts;
823 
824 	return 0;
825 
826 out_free:
827 	kfree(slwt->srh);
828 	kfree(newts);
829 	return err;
830 }
831 
832 static void seg6_local_destroy_state(struct lwtunnel_state *lwt)
833 {
834 	struct seg6_local_lwt *slwt = seg6_local_lwtunnel(lwt);
835 
836 	kfree(slwt->srh);
837 }
838 
839 static int seg6_local_fill_encap(struct sk_buff *skb,
840 				 struct lwtunnel_state *lwt)
841 {
842 	struct seg6_local_lwt *slwt = seg6_local_lwtunnel(lwt);
843 	struct seg6_action_param *param;
844 	int i, err;
845 
846 	if (nla_put_u32(skb, SEG6_LOCAL_ACTION, slwt->action))
847 		return -EMSGSIZE;
848 
849 	for (i = 0; i < SEG6_LOCAL_MAX + 1; i++) {
850 		if (slwt->desc->attrs & (1 << i)) {
851 			param = &seg6_action_params[i];
852 			err = param->put(skb, slwt);
853 			if (err < 0)
854 				return err;
855 		}
856 	}
857 
858 	return 0;
859 }
860 
861 static int seg6_local_get_encap_size(struct lwtunnel_state *lwt)
862 {
863 	struct seg6_local_lwt *slwt = seg6_local_lwtunnel(lwt);
864 	unsigned long attrs;
865 	int nlsize;
866 
867 	nlsize = nla_total_size(4); /* action */
868 
869 	attrs = slwt->desc->attrs;
870 
871 	if (attrs & (1 << SEG6_LOCAL_SRH))
872 		nlsize += nla_total_size((slwt->srh->hdrlen + 1) << 3);
873 
874 	if (attrs & (1 << SEG6_LOCAL_TABLE))
875 		nlsize += nla_total_size(4);
876 
877 	if (attrs & (1 << SEG6_LOCAL_NH4))
878 		nlsize += nla_total_size(4);
879 
880 	if (attrs & (1 << SEG6_LOCAL_NH6))
881 		nlsize += nla_total_size(16);
882 
883 	if (attrs & (1 << SEG6_LOCAL_IIF))
884 		nlsize += nla_total_size(4);
885 
886 	if (attrs & (1 << SEG6_LOCAL_OIF))
887 		nlsize += nla_total_size(4);
888 
889 	return nlsize;
890 }
891 
892 static int seg6_local_cmp_encap(struct lwtunnel_state *a,
893 				struct lwtunnel_state *b)
894 {
895 	struct seg6_local_lwt *slwt_a, *slwt_b;
896 	struct seg6_action_param *param;
897 	int i;
898 
899 	slwt_a = seg6_local_lwtunnel(a);
900 	slwt_b = seg6_local_lwtunnel(b);
901 
902 	if (slwt_a->action != slwt_b->action)
903 		return 1;
904 
905 	if (slwt_a->desc->attrs != slwt_b->desc->attrs)
906 		return 1;
907 
908 	for (i = 0; i < SEG6_LOCAL_MAX + 1; i++) {
909 		if (slwt_a->desc->attrs & (1 << i)) {
910 			param = &seg6_action_params[i];
911 			if (param->cmp(slwt_a, slwt_b))
912 				return 1;
913 		}
914 	}
915 
916 	return 0;
917 }
918 
919 static const struct lwtunnel_encap_ops seg6_local_ops = {
920 	.build_state	= seg6_local_build_state,
921 	.destroy_state	= seg6_local_destroy_state,
922 	.input		= seg6_local_input,
923 	.fill_encap	= seg6_local_fill_encap,
924 	.get_encap_size	= seg6_local_get_encap_size,
925 	.cmp_encap	= seg6_local_cmp_encap,
926 	.owner		= THIS_MODULE,
927 };
928 
929 int __init seg6_local_init(void)
930 {
931 	return lwtunnel_encap_add_ops(&seg6_local_ops,
932 				      LWTUNNEL_ENCAP_SEG6_LOCAL);
933 }
934 
935 void seg6_local_exit(void)
936 {
937 	lwtunnel_encap_del_ops(&seg6_local_ops, LWTUNNEL_ENCAP_SEG6_LOCAL);
938 }
939