xref: /openbmc/linux/net/ipv6/seg6_local.c (revision 160b8e75) 
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 	len = (srh->hdrlen + 1) << 3;
76 
77 	if (!pskb_may_pull(skb, srhoff + len))
78 		return NULL;
79 
80 	if (!seg6_validate_srh(srh, len))
81 		return NULL;
82 
83 	return srh;
84 }
85 
86 static struct ipv6_sr_hdr *get_and_validate_srh(struct sk_buff *skb)
87 {
88 	struct ipv6_sr_hdr *srh;
89 
90 	srh = get_srh(skb);
91 	if (!srh)
92 		return NULL;
93 
94 	if (srh->segments_left == 0)
95 		return NULL;
96 
97 #ifdef CONFIG_IPV6_SEG6_HMAC
98 	if (!seg6_hmac_validate_skb(skb))
99 		return NULL;
100 #endif
101 
102 	return srh;
103 }
104 
105 static bool decap_and_validate(struct sk_buff *skb, int proto)
106 {
107 	struct ipv6_sr_hdr *srh;
108 	unsigned int off = 0;
109 
110 	srh = get_srh(skb);
111 	if (srh && srh->segments_left > 0)
112 		return false;
113 
114 #ifdef CONFIG_IPV6_SEG6_HMAC
115 	if (srh && !seg6_hmac_validate_skb(skb))
116 		return false;
117 #endif
118 
119 	if (ipv6_find_hdr(skb, &off, proto, NULL, NULL) < 0)
120 		return false;
121 
122 	if (!pskb_pull(skb, off))
123 		return false;
124 
125 	skb_postpull_rcsum(skb, skb_network_header(skb), off);
126 
127 	skb_reset_network_header(skb);
128 	skb_reset_transport_header(skb);
129 	skb->encapsulation = 0;
130 
131 	return true;
132 }
133 
134 static void advance_nextseg(struct ipv6_sr_hdr *srh, struct in6_addr *daddr)
135 {
136 	struct in6_addr *addr;
137 
138 	srh->segments_left--;
139 	addr = srh->segments + srh->segments_left;
140 	*daddr = *addr;
141 }
142 
143 static void lookup_nexthop(struct sk_buff *skb, struct in6_addr *nhaddr,
144 			   u32 tbl_id)
145 {
146 	struct net *net = dev_net(skb->dev);
147 	struct ipv6hdr *hdr = ipv6_hdr(skb);
148 	int flags = RT6_LOOKUP_F_HAS_SADDR;
149 	struct dst_entry *dst = NULL;
150 	struct rt6_info *rt;
151 	struct flowi6 fl6;
152 
153 	fl6.flowi6_iif = skb->dev->ifindex;
154 	fl6.daddr = nhaddr ? *nhaddr : hdr->daddr;
155 	fl6.saddr = hdr->saddr;
156 	fl6.flowlabel = ip6_flowinfo(hdr);
157 	fl6.flowi6_mark = skb->mark;
158 	fl6.flowi6_proto = hdr->nexthdr;
159 
160 	if (nhaddr)
161 		fl6.flowi6_flags = FLOWI_FLAG_KNOWN_NH;
162 
163 	if (!tbl_id) {
164 		dst = ip6_route_input_lookup(net, skb->dev, &fl6, flags);
165 	} else {
166 		struct fib6_table *table;
167 
168 		table = fib6_get_table(net, tbl_id);
169 		if (!table)
170 			goto out;
171 
172 		rt = ip6_pol_route(net, table, 0, &fl6, flags);
173 		dst = &rt->dst;
174 	}
175 
176 	if (dst && dst->dev->flags & IFF_LOOPBACK && !dst->error) {
177 		dst_release(dst);
178 		dst = NULL;
179 	}
180 
181 out:
182 	if (!dst) {
183 		rt = net->ipv6.ip6_blk_hole_entry;
184 		dst = &rt->dst;
185 		dst_hold(dst);
186 	}
187 
188 	skb_dst_drop(skb);
189 	skb_dst_set(skb, dst);
190 }
191 
192 /* regular endpoint function */
193 static int input_action_end(struct sk_buff *skb, struct seg6_local_lwt *slwt)
194 {
195 	struct ipv6_sr_hdr *srh;
196 
197 	srh = get_and_validate_srh(skb);
198 	if (!srh)
199 		goto drop;
200 
201 	advance_nextseg(srh, &ipv6_hdr(skb)->daddr);
202 
203 	lookup_nexthop(skb, NULL, 0);
204 
205 	return dst_input(skb);
206 
207 drop:
208 	kfree_skb(skb);
209 	return -EINVAL;
210 }
211 
212 /* regular endpoint, and forward to specified nexthop */
213 static int input_action_end_x(struct sk_buff *skb, struct seg6_local_lwt *slwt)
214 {
215 	struct ipv6_sr_hdr *srh;
216 
217 	srh = get_and_validate_srh(skb);
218 	if (!srh)
219 		goto drop;
220 
221 	advance_nextseg(srh, &ipv6_hdr(skb)->daddr);
222 
223 	lookup_nexthop(skb, &slwt->nh6, 0);
224 
225 	return dst_input(skb);
226 
227 drop:
228 	kfree_skb(skb);
229 	return -EINVAL;
230 }
231 
232 static int input_action_end_t(struct sk_buff *skb, struct seg6_local_lwt *slwt)
233 {
234 	struct ipv6_sr_hdr *srh;
235 
236 	srh = get_and_validate_srh(skb);
237 	if (!srh)
238 		goto drop;
239 
240 	advance_nextseg(srh, &ipv6_hdr(skb)->daddr);
241 
242 	lookup_nexthop(skb, NULL, slwt->table);
243 
244 	return dst_input(skb);
245 
246 drop:
247 	kfree_skb(skb);
248 	return -EINVAL;
249 }
250 
251 /* decapsulate and forward inner L2 frame on specified interface */
252 static int input_action_end_dx2(struct sk_buff *skb,
253 				struct seg6_local_lwt *slwt)
254 {
255 	struct net *net = dev_net(skb->dev);
256 	struct net_device *odev;
257 	struct ethhdr *eth;
258 
259 	if (!decap_and_validate(skb, NEXTHDR_NONE))
260 		goto drop;
261 
262 	if (!pskb_may_pull(skb, ETH_HLEN))
263 		goto drop;
264 
265 	skb_reset_mac_header(skb);
266 	eth = (struct ethhdr *)skb->data;
267 
268 	/* To determine the frame's protocol, we assume it is 802.3. This avoids
269 	 * a call to eth_type_trans(), which is not really relevant for our
270 	 * use case.
271 	 */
272 	if (!eth_proto_is_802_3(eth->h_proto))
273 		goto drop;
274 
275 	odev = dev_get_by_index_rcu(net, slwt->oif);
276 	if (!odev)
277 		goto drop;
278 
279 	/* As we accept Ethernet frames, make sure the egress device is of
280 	 * the correct type.
281 	 */
282 	if (odev->type != ARPHRD_ETHER)
283 		goto drop;
284 
285 	if (!(odev->flags & IFF_UP) || !netif_carrier_ok(odev))
286 		goto drop;
287 
288 	skb_orphan(skb);
289 
290 	if (skb_warn_if_lro(skb))
291 		goto drop;
292 
293 	skb_forward_csum(skb);
294 
295 	if (skb->len - ETH_HLEN > odev->mtu)
296 		goto drop;
297 
298 	skb->dev = odev;
299 	skb->protocol = eth->h_proto;
300 
301 	return dev_queue_xmit(skb);
302 
303 drop:
304 	kfree_skb(skb);
305 	return -EINVAL;
306 }
307 
308 /* decapsulate and forward to specified nexthop */
309 static int input_action_end_dx6(struct sk_buff *skb,
310 				struct seg6_local_lwt *slwt)
311 {
312 	struct in6_addr *nhaddr = NULL;
313 
314 	/* this function accepts IPv6 encapsulated packets, with either
315 	 * an SRH with SL=0, or no SRH.
316 	 */
317 
318 	if (!decap_and_validate(skb, IPPROTO_IPV6))
319 		goto drop;
320 
321 	if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
322 		goto drop;
323 
324 	/* The inner packet is not associated to any local interface,
325 	 * so we do not call netif_rx().
326 	 *
327 	 * If slwt->nh6 is set to ::, then lookup the nexthop for the
328 	 * inner packet's DA. Otherwise, use the specified nexthop.
329 	 */
330 
331 	if (!ipv6_addr_any(&slwt->nh6))
332 		nhaddr = &slwt->nh6;
333 
334 	lookup_nexthop(skb, nhaddr, 0);
335 
336 	return dst_input(skb);
337 drop:
338 	kfree_skb(skb);
339 	return -EINVAL;
340 }
341 
342 static int input_action_end_dx4(struct sk_buff *skb,
343 				struct seg6_local_lwt *slwt)
344 {
345 	struct iphdr *iph;
346 	__be32 nhaddr;
347 	int err;
348 
349 	if (!decap_and_validate(skb, IPPROTO_IPIP))
350 		goto drop;
351 
352 	if (!pskb_may_pull(skb, sizeof(struct iphdr)))
353 		goto drop;
354 
355 	skb->protocol = htons(ETH_P_IP);
356 
357 	iph = ip_hdr(skb);
358 
359 	nhaddr = slwt->nh4.s_addr ?: iph->daddr;
360 
361 	skb_dst_drop(skb);
362 
363 	err = ip_route_input(skb, nhaddr, iph->saddr, 0, skb->dev);
364 	if (err)
365 		goto drop;
366 
367 	return dst_input(skb);
368 
369 drop:
370 	kfree_skb(skb);
371 	return -EINVAL;
372 }
373 
374 static int input_action_end_dt6(struct sk_buff *skb,
375 				struct seg6_local_lwt *slwt)
376 {
377 	if (!decap_and_validate(skb, IPPROTO_IPV6))
378 		goto drop;
379 
380 	if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
381 		goto drop;
382 
383 	lookup_nexthop(skb, NULL, slwt->table);
384 
385 	return dst_input(skb);
386 
387 drop:
388 	kfree_skb(skb);
389 	return -EINVAL;
390 }
391 
392 /* push an SRH on top of the current one */
393 static int input_action_end_b6(struct sk_buff *skb, struct seg6_local_lwt *slwt)
394 {
395 	struct ipv6_sr_hdr *srh;
396 	int err = -EINVAL;
397 
398 	srh = get_and_validate_srh(skb);
399 	if (!srh)
400 		goto drop;
401 
402 	err = seg6_do_srh_inline(skb, slwt->srh);
403 	if (err)
404 		goto drop;
405 
406 	ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
407 	skb_set_transport_header(skb, sizeof(struct ipv6hdr));
408 
409 	lookup_nexthop(skb, NULL, 0);
410 
411 	return dst_input(skb);
412 
413 drop:
414 	kfree_skb(skb);
415 	return err;
416 }
417 
418 /* encapsulate within an outer IPv6 header and a specified SRH */
419 static int input_action_end_b6_encap(struct sk_buff *skb,
420 				     struct seg6_local_lwt *slwt)
421 {
422 	struct ipv6_sr_hdr *srh;
423 	int err = -EINVAL;
424 
425 	srh = get_and_validate_srh(skb);
426 	if (!srh)
427 		goto drop;
428 
429 	advance_nextseg(srh, &ipv6_hdr(skb)->daddr);
430 
431 	skb_reset_inner_headers(skb);
432 	skb->encapsulation = 1;
433 
434 	err = seg6_do_srh_encap(skb, slwt->srh, IPPROTO_IPV6);
435 	if (err)
436 		goto drop;
437 
438 	ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
439 	skb_set_transport_header(skb, sizeof(struct ipv6hdr));
440 
441 	lookup_nexthop(skb, NULL, 0);
442 
443 	return dst_input(skb);
444 
445 drop:
446 	kfree_skb(skb);
447 	return err;
448 }
449 
450 static struct seg6_action_desc seg6_action_table[] = {
451 	{
452 		.action		= SEG6_LOCAL_ACTION_END,
453 		.attrs		= 0,
454 		.input		= input_action_end,
455 	},
456 	{
457 		.action		= SEG6_LOCAL_ACTION_END_X,
458 		.attrs		= (1 << SEG6_LOCAL_NH6),
459 		.input		= input_action_end_x,
460 	},
461 	{
462 		.action		= SEG6_LOCAL_ACTION_END_T,
463 		.attrs		= (1 << SEG6_LOCAL_TABLE),
464 		.input		= input_action_end_t,
465 	},
466 	{
467 		.action		= SEG6_LOCAL_ACTION_END_DX2,
468 		.attrs		= (1 << SEG6_LOCAL_OIF),
469 		.input		= input_action_end_dx2,
470 	},
471 	{
472 		.action		= SEG6_LOCAL_ACTION_END_DX6,
473 		.attrs		= (1 << SEG6_LOCAL_NH6),
474 		.input		= input_action_end_dx6,
475 	},
476 	{
477 		.action		= SEG6_LOCAL_ACTION_END_DX4,
478 		.attrs		= (1 << SEG6_LOCAL_NH4),
479 		.input		= input_action_end_dx4,
480 	},
481 	{
482 		.action		= SEG6_LOCAL_ACTION_END_DT6,
483 		.attrs		= (1 << SEG6_LOCAL_TABLE),
484 		.input		= input_action_end_dt6,
485 	},
486 	{
487 		.action		= SEG6_LOCAL_ACTION_END_B6,
488 		.attrs		= (1 << SEG6_LOCAL_SRH),
489 		.input		= input_action_end_b6,
490 	},
491 	{
492 		.action		= SEG6_LOCAL_ACTION_END_B6_ENCAP,
493 		.attrs		= (1 << SEG6_LOCAL_SRH),
494 		.input		= input_action_end_b6_encap,
495 		.static_headroom	= sizeof(struct ipv6hdr),
496 	}
497 };
498 
499 static struct seg6_action_desc *__get_action_desc(int action)
500 {
501 	struct seg6_action_desc *desc;
502 	int i, count;
503 
504 	count = ARRAY_SIZE(seg6_action_table);
505 	for (i = 0; i < count; i++) {
506 		desc = &seg6_action_table[i];
507 		if (desc->action == action)
508 			return desc;
509 	}
510 
511 	return NULL;
512 }
513 
514 static int seg6_local_input(struct sk_buff *skb)
515 {
516 	struct dst_entry *orig_dst = skb_dst(skb);
517 	struct seg6_action_desc *desc;
518 	struct seg6_local_lwt *slwt;
519 
520 	if (skb->protocol != htons(ETH_P_IPV6)) {
521 		kfree_skb(skb);
522 		return -EINVAL;
523 	}
524 
525 	slwt = seg6_local_lwtunnel(orig_dst->lwtstate);
526 	desc = slwt->desc;
527 
528 	return desc->input(skb, slwt);
529 }
530 
531 static const struct nla_policy seg6_local_policy[SEG6_LOCAL_MAX + 1] = {
532 	[SEG6_LOCAL_ACTION]	= { .type = NLA_U32 },
533 	[SEG6_LOCAL_SRH]	= { .type = NLA_BINARY },
534 	[SEG6_LOCAL_TABLE]	= { .type = NLA_U32 },
535 	[SEG6_LOCAL_NH4]	= { .type = NLA_BINARY,
536 				    .len = sizeof(struct in_addr) },
537 	[SEG6_LOCAL_NH6]	= { .type = NLA_BINARY,
538 				    .len = sizeof(struct in6_addr) },
539 	[SEG6_LOCAL_IIF]	= { .type = NLA_U32 },
540 	[SEG6_LOCAL_OIF]	= { .type = NLA_U32 },
541 };
542 
543 static int parse_nla_srh(struct nlattr **attrs, struct seg6_local_lwt *slwt)
544 {
545 	struct ipv6_sr_hdr *srh;
546 	int len;
547 
548 	srh = nla_data(attrs[SEG6_LOCAL_SRH]);
549 	len = nla_len(attrs[SEG6_LOCAL_SRH]);
550 
551 	/* SRH must contain at least one segment */
552 	if (len < sizeof(*srh) + sizeof(struct in6_addr))
553 		return -EINVAL;
554 
555 	if (!seg6_validate_srh(srh, len))
556 		return -EINVAL;
557 
558 	slwt->srh = kmalloc(len, GFP_KERNEL);
559 	if (!slwt->srh)
560 		return -ENOMEM;
561 
562 	memcpy(slwt->srh, srh, len);
563 
564 	slwt->headroom += len;
565 
566 	return 0;
567 }
568 
569 static int put_nla_srh(struct sk_buff *skb, struct seg6_local_lwt *slwt)
570 {
571 	struct ipv6_sr_hdr *srh;
572 	struct nlattr *nla;
573 	int len;
574 
575 	srh = slwt->srh;
576 	len = (srh->hdrlen + 1) << 3;
577 
578 	nla = nla_reserve(skb, SEG6_LOCAL_SRH, len);
579 	if (!nla)
580 		return -EMSGSIZE;
581 
582 	memcpy(nla_data(nla), srh, len);
583 
584 	return 0;
585 }
586 
587 static int cmp_nla_srh(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
588 {
589 	int len = (a->srh->hdrlen + 1) << 3;
590 
591 	if (len != ((b->srh->hdrlen + 1) << 3))
592 		return 1;
593 
594 	return memcmp(a->srh, b->srh, len);
595 }
596 
597 static int parse_nla_table(struct nlattr **attrs, struct seg6_local_lwt *slwt)
598 {
599 	slwt->table = nla_get_u32(attrs[SEG6_LOCAL_TABLE]);
600 
601 	return 0;
602 }
603 
604 static int put_nla_table(struct sk_buff *skb, struct seg6_local_lwt *slwt)
605 {
606 	if (nla_put_u32(skb, SEG6_LOCAL_TABLE, slwt->table))
607 		return -EMSGSIZE;
608 
609 	return 0;
610 }
611 
612 static int cmp_nla_table(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
613 {
614 	if (a->table != b->table)
615 		return 1;
616 
617 	return 0;
618 }
619 
620 static int parse_nla_nh4(struct nlattr **attrs, struct seg6_local_lwt *slwt)
621 {
622 	memcpy(&slwt->nh4, nla_data(attrs[SEG6_LOCAL_NH4]),
623 	       sizeof(struct in_addr));
624 
625 	return 0;
626 }
627 
628 static int put_nla_nh4(struct sk_buff *skb, struct seg6_local_lwt *slwt)
629 {
630 	struct nlattr *nla;
631 
632 	nla = nla_reserve(skb, SEG6_LOCAL_NH4, sizeof(struct in_addr));
633 	if (!nla)
634 		return -EMSGSIZE;
635 
636 	memcpy(nla_data(nla), &slwt->nh4, sizeof(struct in_addr));
637 
638 	return 0;
639 }
640 
641 static int cmp_nla_nh4(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
642 {
643 	return memcmp(&a->nh4, &b->nh4, sizeof(struct in_addr));
644 }
645 
646 static int parse_nla_nh6(struct nlattr **attrs, struct seg6_local_lwt *slwt)
647 {
648 	memcpy(&slwt->nh6, nla_data(attrs[SEG6_LOCAL_NH6]),
649 	       sizeof(struct in6_addr));
650 
651 	return 0;
652 }
653 
654 static int put_nla_nh6(struct sk_buff *skb, struct seg6_local_lwt *slwt)
655 {
656 	struct nlattr *nla;
657 
658 	nla = nla_reserve(skb, SEG6_LOCAL_NH6, sizeof(struct in6_addr));
659 	if (!nla)
660 		return -EMSGSIZE;
661 
662 	memcpy(nla_data(nla), &slwt->nh6, sizeof(struct in6_addr));
663 
664 	return 0;
665 }
666 
667 static int cmp_nla_nh6(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
668 {
669 	return memcmp(&a->nh6, &b->nh6, sizeof(struct in6_addr));
670 }
671 
672 static int parse_nla_iif(struct nlattr **attrs, struct seg6_local_lwt *slwt)
673 {
674 	slwt->iif = nla_get_u32(attrs[SEG6_LOCAL_IIF]);
675 
676 	return 0;
677 }
678 
679 static int put_nla_iif(struct sk_buff *skb, struct seg6_local_lwt *slwt)
680 {
681 	if (nla_put_u32(skb, SEG6_LOCAL_IIF, slwt->iif))
682 		return -EMSGSIZE;
683 
684 	return 0;
685 }
686 
687 static int cmp_nla_iif(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
688 {
689 	if (a->iif != b->iif)
690 		return 1;
691 
692 	return 0;
693 }
694 
695 static int parse_nla_oif(struct nlattr **attrs, struct seg6_local_lwt *slwt)
696 {
697 	slwt->oif = nla_get_u32(attrs[SEG6_LOCAL_OIF]);
698 
699 	return 0;
700 }
701 
702 static int put_nla_oif(struct sk_buff *skb, struct seg6_local_lwt *slwt)
703 {
704 	if (nla_put_u32(skb, SEG6_LOCAL_OIF, slwt->oif))
705 		return -EMSGSIZE;
706 
707 	return 0;
708 }
709 
710 static int cmp_nla_oif(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
711 {
712 	if (a->oif != b->oif)
713 		return 1;
714 
715 	return 0;
716 }
717 
718 struct seg6_action_param {
719 	int (*parse)(struct nlattr **attrs, struct seg6_local_lwt *slwt);
720 	int (*put)(struct sk_buff *skb, struct seg6_local_lwt *slwt);
721 	int (*cmp)(struct seg6_local_lwt *a, struct seg6_local_lwt *b);
722 };
723 
724 static struct seg6_action_param seg6_action_params[SEG6_LOCAL_MAX + 1] = {
725 	[SEG6_LOCAL_SRH]	= { .parse = parse_nla_srh,
726 				    .put = put_nla_srh,
727 				    .cmp = cmp_nla_srh },
728 
729 	[SEG6_LOCAL_TABLE]	= { .parse = parse_nla_table,
730 				    .put = put_nla_table,
731 				    .cmp = cmp_nla_table },
732 
733 	[SEG6_LOCAL_NH4]	= { .parse = parse_nla_nh4,
734 				    .put = put_nla_nh4,
735 				    .cmp = cmp_nla_nh4 },
736 
737 	[SEG6_LOCAL_NH6]	= { .parse = parse_nla_nh6,
738 				    .put = put_nla_nh6,
739 				    .cmp = cmp_nla_nh6 },
740 
741 	[SEG6_LOCAL_IIF]	= { .parse = parse_nla_iif,
742 				    .put = put_nla_iif,
743 				    .cmp = cmp_nla_iif },
744 
745 	[SEG6_LOCAL_OIF]	= { .parse = parse_nla_oif,
746 				    .put = put_nla_oif,
747 				    .cmp = cmp_nla_oif },
748 };
749 
750 static int parse_nla_action(struct nlattr **attrs, struct seg6_local_lwt *slwt)
751 {
752 	struct seg6_action_param *param;
753 	struct seg6_action_desc *desc;
754 	int i, err;
755 
756 	desc = __get_action_desc(slwt->action);
757 	if (!desc)
758 		return -EINVAL;
759 
760 	if (!desc->input)
761 		return -EOPNOTSUPP;
762 
763 	slwt->desc = desc;
764 	slwt->headroom += desc->static_headroom;
765 
766 	for (i = 0; i < SEG6_LOCAL_MAX + 1; i++) {
767 		if (desc->attrs & (1 << i)) {
768 			if (!attrs[i])
769 				return -EINVAL;
770 
771 			param = &seg6_action_params[i];
772 
773 			err = param->parse(attrs, slwt);
774 			if (err < 0)
775 				return err;
776 		}
777 	}
778 
779 	return 0;
780 }
781 
782 static int seg6_local_build_state(struct nlattr *nla, unsigned int family,
783 				  const void *cfg, struct lwtunnel_state **ts,
784 				  struct netlink_ext_ack *extack)
785 {
786 	struct nlattr *tb[SEG6_LOCAL_MAX + 1];
787 	struct lwtunnel_state *newts;
788 	struct seg6_local_lwt *slwt;
789 	int err;
790 
791 	if (family != AF_INET6)
792 		return -EINVAL;
793 
794 	err = nla_parse_nested(tb, SEG6_LOCAL_MAX, nla, seg6_local_policy,
795 			       extack);
796 
797 	if (err < 0)
798 		return err;
799 
800 	if (!tb[SEG6_LOCAL_ACTION])
801 		return -EINVAL;
802 
803 	newts = lwtunnel_state_alloc(sizeof(*slwt));
804 	if (!newts)
805 		return -ENOMEM;
806 
807 	slwt = seg6_local_lwtunnel(newts);
808 	slwt->action = nla_get_u32(tb[SEG6_LOCAL_ACTION]);
809 
810 	err = parse_nla_action(tb, slwt);
811 	if (err < 0)
812 		goto out_free;
813 
814 	newts->type = LWTUNNEL_ENCAP_SEG6_LOCAL;
815 	newts->flags = LWTUNNEL_STATE_INPUT_REDIRECT;
816 	newts->headroom = slwt->headroom;
817 
818 	*ts = newts;
819 
820 	return 0;
821 
822 out_free:
823 	kfree(slwt->srh);
824 	kfree(newts);
825 	return err;
826 }
827 
828 static void seg6_local_destroy_state(struct lwtunnel_state *lwt)
829 {
830 	struct seg6_local_lwt *slwt = seg6_local_lwtunnel(lwt);
831 
832 	kfree(slwt->srh);
833 }
834 
835 static int seg6_local_fill_encap(struct sk_buff *skb,
836 				 struct lwtunnel_state *lwt)
837 {
838 	struct seg6_local_lwt *slwt = seg6_local_lwtunnel(lwt);
839 	struct seg6_action_param *param;
840 	int i, err;
841 
842 	if (nla_put_u32(skb, SEG6_LOCAL_ACTION, slwt->action))
843 		return -EMSGSIZE;
844 
845 	for (i = 0; i < SEG6_LOCAL_MAX + 1; i++) {
846 		if (slwt->desc->attrs & (1 << i)) {
847 			param = &seg6_action_params[i];
848 			err = param->put(skb, slwt);
849 			if (err < 0)
850 				return err;
851 		}
852 	}
853 
854 	return 0;
855 }
856 
857 static int seg6_local_get_encap_size(struct lwtunnel_state *lwt)
858 {
859 	struct seg6_local_lwt *slwt = seg6_local_lwtunnel(lwt);
860 	unsigned long attrs;
861 	int nlsize;
862 
863 	nlsize = nla_total_size(4); /* action */
864 
865 	attrs = slwt->desc->attrs;
866 
867 	if (attrs & (1 << SEG6_LOCAL_SRH))
868 		nlsize += nla_total_size((slwt->srh->hdrlen + 1) << 3);
869 
870 	if (attrs & (1 << SEG6_LOCAL_TABLE))
871 		nlsize += nla_total_size(4);
872 
873 	if (attrs & (1 << SEG6_LOCAL_NH4))
874 		nlsize += nla_total_size(4);
875 
876 	if (attrs & (1 << SEG6_LOCAL_NH6))
877 		nlsize += nla_total_size(16);
878 
879 	if (attrs & (1 << SEG6_LOCAL_IIF))
880 		nlsize += nla_total_size(4);
881 
882 	if (attrs & (1 << SEG6_LOCAL_OIF))
883 		nlsize += nla_total_size(4);
884 
885 	return nlsize;
886 }
887 
888 static int seg6_local_cmp_encap(struct lwtunnel_state *a,
889 				struct lwtunnel_state *b)
890 {
891 	struct seg6_local_lwt *slwt_a, *slwt_b;
892 	struct seg6_action_param *param;
893 	int i;
894 
895 	slwt_a = seg6_local_lwtunnel(a);
896 	slwt_b = seg6_local_lwtunnel(b);
897 
898 	if (slwt_a->action != slwt_b->action)
899 		return 1;
900 
901 	if (slwt_a->desc->attrs != slwt_b->desc->attrs)
902 		return 1;
903 
904 	for (i = 0; i < SEG6_LOCAL_MAX + 1; i++) {
905 		if (slwt_a->desc->attrs & (1 << i)) {
906 			param = &seg6_action_params[i];
907 			if (param->cmp(slwt_a, slwt_b))
908 				return 1;
909 		}
910 	}
911 
912 	return 0;
913 }
914 
915 static const struct lwtunnel_encap_ops seg6_local_ops = {
916 	.build_state	= seg6_local_build_state,
917 	.destroy_state	= seg6_local_destroy_state,
918 	.input		= seg6_local_input,
919 	.fill_encap	= seg6_local_fill_encap,
920 	.get_encap_size	= seg6_local_get_encap_size,
921 	.cmp_encap	= seg6_local_cmp_encap,
922 	.owner		= THIS_MODULE,
923 };
924 
925 int __init seg6_local_init(void)
926 {
927 	return lwtunnel_encap_add_ops(&seg6_local_ops,
928 				      LWTUNNEL_ENCAP_SEG6_LOCAL);
929 }
930 
931 void seg6_local_exit(void)
932 {
933 	lwtunnel_encap_del_ops(&seg6_local_ops, LWTUNNEL_ENCAP_SEG6_LOCAL);
934 }
935