1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 *  SR-IPv6 implementation
  4 *
  5 *  Author:
  6 *  David Lebrun <david.lebrun@uclouvain.be>
  7 */
  8
  9#include <linux/types.h>
 10#include <linux/skbuff.h>
 11#include <linux/net.h>
 12#include <linux/module.h>
 13#include <net/ip.h>
 14#include <net/ip_tunnels.h>
 15#include <net/lwtunnel.h>
 16#include <net/netevent.h>
 17#include <net/netns/generic.h>
 18#include <net/ip6_fib.h>
 19#include <net/route.h>
 20#include <net/seg6.h>
 21#include <linux/seg6.h>
 22#include <linux/seg6_iptunnel.h>
 23#include <net/addrconf.h>
 24#include <net/ip6_route.h>
 25#include <net/dst_cache.h>
 26#ifdef CONFIG_IPV6_SEG6_HMAC
 27#include <net/seg6_hmac.h>
 28#endif
 29#include <linux/netfilter.h>
 30
 31static size_t seg6_lwt_headroom(struct seg6_iptunnel_encap *tuninfo)
 32{
 33	int head = 0;
 34
 35	switch (tuninfo->mode) {
 36	case SEG6_IPTUN_MODE_INLINE:
 37		break;
 38	case SEG6_IPTUN_MODE_ENCAP:
 39	case SEG6_IPTUN_MODE_ENCAP_RED:
 40		head = sizeof(struct ipv6hdr);
 41		break;
 42	case SEG6_IPTUN_MODE_L2ENCAP:
 43	case SEG6_IPTUN_MODE_L2ENCAP_RED:
 44		return 0;
 45	}
 46
 47	return ((tuninfo->srh->hdrlen + 1) << 3) + head;
 48}
 49
 50struct seg6_lwt {
 51	struct dst_cache cache;
 52	struct seg6_iptunnel_encap tuninfo[];
 53};
 54
 55static inline struct seg6_lwt *seg6_lwt_lwtunnel(struct lwtunnel_state *lwt)
 56{
 57	return (struct seg6_lwt *)lwt->data;
 58}
 59
 60static inline struct seg6_iptunnel_encap *
 61seg6_encap_lwtunnel(struct lwtunnel_state *lwt)
 62{
 63	return seg6_lwt_lwtunnel(lwt)->tuninfo;
 64}
 65
 66static const struct nla_policy seg6_iptunnel_policy[SEG6_IPTUNNEL_MAX + 1] = {
 67	[SEG6_IPTUNNEL_SRH]	= { .type = NLA_BINARY },
 68};
 69
 70static int nla_put_srh(struct sk_buff *skb, int attrtype,
 71		       struct seg6_iptunnel_encap *tuninfo)
 72{
 73	struct seg6_iptunnel_encap *data;
 74	struct nlattr *nla;
 75	int len;
 76
 77	len = SEG6_IPTUN_ENCAP_SIZE(tuninfo);
 78
 79	nla = nla_reserve(skb, attrtype, len);
 80	if (!nla)
 81		return -EMSGSIZE;
 82
 83	data = nla_data(nla);
 84	memcpy(data, tuninfo, len);
 85
 86	return 0;
 87}
 88
 89static void set_tun_src(struct net *net, struct net_device *dev,
 90			struct in6_addr *daddr, struct in6_addr *saddr)
 91{
 92	struct seg6_pernet_data *sdata = seg6_pernet(net);
 93	struct in6_addr *tun_src;
 94
 95	rcu_read_lock();
 96
 97	tun_src = rcu_dereference(sdata->tun_src);
 98
 99	if (!ipv6_addr_any(tun_src)) {
100		memcpy(saddr, tun_src, sizeof(struct in6_addr));
101	} else {
102		ipv6_dev_get_saddr(net, dev, daddr, IPV6_PREFER_SRC_PUBLIC,
103				   saddr);
104	}
105
106	rcu_read_unlock();
107}
108
109/* Compute flowlabel for outer IPv6 header */
110static __be32 seg6_make_flowlabel(struct net *net, struct sk_buff *skb,
111				  struct ipv6hdr *inner_hdr)
112{
113	int do_flowlabel = net->ipv6.sysctl.seg6_flowlabel;
114	__be32 flowlabel = 0;
115	u32 hash;
116
117	if (do_flowlabel > 0) {
118		hash = skb_get_hash(skb);
119		hash = rol32(hash, 16);
120		flowlabel = (__force __be32)hash & IPV6_FLOWLABEL_MASK;
121	} else if (!do_flowlabel && skb->protocol == htons(ETH_P_IPV6)) {
122		flowlabel = ip6_flowlabel(inner_hdr);
123	}
124	return flowlabel;
125}
126
127/* encapsulate an IPv6 packet within an outer IPv6 header with a given SRH */
128int seg6_do_srh_encap(struct sk_buff *skb, struct ipv6_sr_hdr *osrh, int proto)
129{
130	struct dst_entry *dst = skb_dst(skb);
131	struct net *net = dev_net(dst->dev);
132	struct ipv6hdr *hdr, *inner_hdr;
133	struct ipv6_sr_hdr *isrh;
134	int hdrlen, tot_len, err;
135	__be32 flowlabel;
136
137	hdrlen = (osrh->hdrlen + 1) << 3;
138	tot_len = hdrlen + sizeof(*hdr);
139
140	err = skb_cow_head(skb, tot_len + skb->mac_len);
141	if (unlikely(err))
142		return err;
143
144	inner_hdr = ipv6_hdr(skb);
145	flowlabel = seg6_make_flowlabel(net, skb, inner_hdr);
146
147	skb_push(skb, tot_len);
148	skb_reset_network_header(skb);
149	skb_mac_header_rebuild(skb);
150	hdr = ipv6_hdr(skb);
151
152	/* inherit tc, flowlabel and hlim
153	 * hlim will be decremented in ip6_forward() afterwards and
154	 * decapsulation will overwrite inner hlim with outer hlim
155	 */
156
157	if (skb->protocol == htons(ETH_P_IPV6)) {
158		ip6_flow_hdr(hdr, ip6_tclass(ip6_flowinfo(inner_hdr)),
159			     flowlabel);
160		hdr->hop_limit = inner_hdr->hop_limit;
161	} else {
162		ip6_flow_hdr(hdr, 0, flowlabel);
163		hdr->hop_limit = ip6_dst_hoplimit(skb_dst(skb));
164
165		memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
166
167		/* the control block has been erased, so we have to set the
168		 * iif once again.
169		 * We read the receiving interface index directly from the
170		 * skb->skb_iif as it is done in the IPv4 receiving path (i.e.:
171		 * ip_rcv_core(...)).
172		 */
173		IP6CB(skb)->iif = skb->skb_iif;
174	}
175
176	hdr->nexthdr = NEXTHDR_ROUTING;
177
178	isrh = (void *)hdr + sizeof(*hdr);
179	memcpy(isrh, osrh, hdrlen);
180
181	isrh->nexthdr = proto;
182
183	hdr->daddr = isrh->segments[isrh->first_segment];
184	set_tun_src(net, dst->dev, &hdr->daddr, &hdr->saddr);
185
186#ifdef CONFIG_IPV6_SEG6_HMAC
187	if (sr_has_hmac(isrh)) {
188		err = seg6_push_hmac(net, &hdr->saddr, isrh);
189		if (unlikely(err))
190			return err;
191	}
192#endif
193
194	hdr->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
195
196	skb_postpush_rcsum(skb, hdr, tot_len);
197
198	return 0;
199}
200EXPORT_SYMBOL_GPL(seg6_do_srh_encap);
201
202/* encapsulate an IPv6 packet within an outer IPv6 header with reduced SRH */
203static int seg6_do_srh_encap_red(struct sk_buff *skb,
204				 struct ipv6_sr_hdr *osrh, int proto)
205{
206	__u8 first_seg = osrh->first_segment;
207	struct dst_entry *dst = skb_dst(skb);
208	struct net *net = dev_net(dst->dev);
209	struct ipv6hdr *hdr, *inner_hdr;
210	int hdrlen = ipv6_optlen(osrh);
211	int red_tlv_offset, tlv_offset;
212	struct ipv6_sr_hdr *isrh;
213	bool skip_srh = false;
214	__be32 flowlabel;
215	int tot_len, err;
216	int red_hdrlen;
217	int tlvs_len;
218
219	if (first_seg > 0) {
220		red_hdrlen = hdrlen - sizeof(struct in6_addr);
221	} else {
222		/* NOTE: if tag/flags and/or other TLVs are introduced in the
223		 * seg6_iptunnel infrastructure, they should be considered when
224		 * deciding to skip the SRH.
225		 */
226		skip_srh = !sr_has_hmac(osrh);
227
228		red_hdrlen = skip_srh ? 0 : hdrlen;
229	}
230
231	tot_len = red_hdrlen + sizeof(struct ipv6hdr);
232
233	err = skb_cow_head(skb, tot_len + skb->mac_len);
234	if (unlikely(err))
235		return err;
236
237	inner_hdr = ipv6_hdr(skb);
238	flowlabel = seg6_make_flowlabel(net, skb, inner_hdr);
239
240	skb_push(skb, tot_len);
241	skb_reset_network_header(skb);
242	skb_mac_header_rebuild(skb);
243	hdr = ipv6_hdr(skb);
244
245	/* based on seg6_do_srh_encap() */
246	if (skb->protocol == htons(ETH_P_IPV6)) {
247		ip6_flow_hdr(hdr, ip6_tclass(ip6_flowinfo(inner_hdr)),
248			     flowlabel);
249		hdr->hop_limit = inner_hdr->hop_limit;
250	} else {
251		ip6_flow_hdr(hdr, 0, flowlabel);
252		hdr->hop_limit = ip6_dst_hoplimit(skb_dst(skb));
253
254		memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
255		IP6CB(skb)->iif = skb->skb_iif;
256	}
257
258	/* no matter if we have to skip the SRH or not, the first segment
259	 * always comes in the pushed IPv6 header.
260	 */
261	hdr->daddr = osrh->segments[first_seg];
262
263	if (skip_srh) {
264		hdr->nexthdr = proto;
265
266		set_tun_src(net, dst->dev, &hdr->daddr, &hdr->saddr);
267		goto out;
268	}
269
270	/* we cannot skip the SRH, slow path */
271
272	hdr->nexthdr = NEXTHDR_ROUTING;
273	isrh = (void *)hdr + sizeof(struct ipv6hdr);
274
275	if (unlikely(!first_seg)) {
276		/* this is a very rare case; we have only one SID but
277		 * we cannot skip the SRH since we are carrying some
278		 * other info.
279		 */
280		memcpy(isrh, osrh, hdrlen);
281		goto srcaddr;
282	}
283
284	tlv_offset = sizeof(*osrh) + (first_seg + 1) * sizeof(struct in6_addr);
285	red_tlv_offset = tlv_offset - sizeof(struct in6_addr);
286
287	memcpy(isrh, osrh, red_tlv_offset);
288
289	tlvs_len = hdrlen - tlv_offset;
290	if (unlikely(tlvs_len > 0)) {
291		const void *s = (const void *)osrh + tlv_offset;
292		void *d = (void *)isrh + red_tlv_offset;
293
294		memcpy(d, s, tlvs_len);
295	}
296
297	--isrh->first_segment;
298	isrh->hdrlen -= 2;
299
300srcaddr:
301	isrh->nexthdr = proto;
302	set_tun_src(net, dst->dev, &hdr->daddr, &hdr->saddr);
303
304#ifdef CONFIG_IPV6_SEG6_HMAC
305	if (unlikely(!skip_srh && sr_has_hmac(isrh))) {
306		err = seg6_push_hmac(net, &hdr->saddr, isrh);
307		if (unlikely(err))
308			return err;
309	}
310#endif
311
312out:
313	hdr->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
314
315	skb_postpush_rcsum(skb, hdr, tot_len);
316
317	return 0;
318}
319
320/* insert an SRH within an IPv6 packet, just after the IPv6 header */
321int seg6_do_srh_inline(struct sk_buff *skb, struct ipv6_sr_hdr *osrh)
322{
323	struct ipv6hdr *hdr, *oldhdr;
324	struct ipv6_sr_hdr *isrh;
325	int hdrlen, err;
326
327	hdrlen = (osrh->hdrlen + 1) << 3;
328
329	err = skb_cow_head(skb, hdrlen + skb->mac_len);
330	if (unlikely(err))
331		return err;
332
333	oldhdr = ipv6_hdr(skb);
334
335	skb_pull(skb, sizeof(struct ipv6hdr));
336	skb_postpull_rcsum(skb, skb_network_header(skb),
337			   sizeof(struct ipv6hdr));
338
339	skb_push(skb, sizeof(struct ipv6hdr) + hdrlen);
340	skb_reset_network_header(skb);
341	skb_mac_header_rebuild(skb);
342
343	hdr = ipv6_hdr(skb);
344
345	memmove(hdr, oldhdr, sizeof(*hdr));
346
347	isrh = (void *)hdr + sizeof(*hdr);
348	memcpy(isrh, osrh, hdrlen);
349
350	isrh->nexthdr = hdr->nexthdr;
351	hdr->nexthdr = NEXTHDR_ROUTING;
352
353	isrh->segments[0] = hdr->daddr;
354	hdr->daddr = isrh->segments[isrh->first_segment];
355
356#ifdef CONFIG_IPV6_SEG6_HMAC
357	if (sr_has_hmac(isrh)) {
358		struct net *net = dev_net(skb_dst(skb)->dev);
359
360		err = seg6_push_hmac(net, &hdr->saddr, isrh);
361		if (unlikely(err))
362			return err;
363	}
364#endif
365
366	hdr->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
367
368	skb_postpush_rcsum(skb, hdr, sizeof(struct ipv6hdr) + hdrlen);
369
370	return 0;
371}
372EXPORT_SYMBOL_GPL(seg6_do_srh_inline);
373
374static int seg6_do_srh(struct sk_buff *skb)
375{
376	struct dst_entry *dst = skb_dst(skb);
377	struct seg6_iptunnel_encap *tinfo;
378	int proto, err = 0;
379
380	tinfo = seg6_encap_lwtunnel(dst->lwtstate);
381
382	switch (tinfo->mode) {
383	case SEG6_IPTUN_MODE_INLINE:
384		if (skb->protocol != htons(ETH_P_IPV6))
385			return -EINVAL;
386
387		err = seg6_do_srh_inline(skb, tinfo->srh);
388		if (err)
389			return err;
390		break;
391	case SEG6_IPTUN_MODE_ENCAP:
392	case SEG6_IPTUN_MODE_ENCAP_RED:
393		err = iptunnel_handle_offloads(skb, SKB_GSO_IPXIP6);
394		if (err)
395			return err;
396
397		if (skb->protocol == htons(ETH_P_IPV6))
398			proto = IPPROTO_IPV6;
399		else if (skb->protocol == htons(ETH_P_IP))
400			proto = IPPROTO_IPIP;
401		else
402			return -EINVAL;
403
404		if (tinfo->mode == SEG6_IPTUN_MODE_ENCAP)
405			err = seg6_do_srh_encap(skb, tinfo->srh, proto);
406		else
407			err = seg6_do_srh_encap_red(skb, tinfo->srh, proto);
408
409		if (err)
410			return err;
411
412		skb_set_inner_transport_header(skb, skb_transport_offset(skb));
413		skb_set_inner_protocol(skb, skb->protocol);
414		skb->protocol = htons(ETH_P_IPV6);
415		break;
416	case SEG6_IPTUN_MODE_L2ENCAP:
417	case SEG6_IPTUN_MODE_L2ENCAP_RED:
418		if (!skb_mac_header_was_set(skb))
419			return -EINVAL;
420
421		if (pskb_expand_head(skb, skb->mac_len, 0, GFP_ATOMIC) < 0)
422			return -ENOMEM;
423
424		skb_mac_header_rebuild(skb);
425		skb_push(skb, skb->mac_len);
426
427		if (tinfo->mode == SEG6_IPTUN_MODE_L2ENCAP)
428			err = seg6_do_srh_encap(skb, tinfo->srh,
429						IPPROTO_ETHERNET);
430		else
431			err = seg6_do_srh_encap_red(skb, tinfo->srh,
432						    IPPROTO_ETHERNET);
433
434		if (err)
435			return err;
436
437		skb->protocol = htons(ETH_P_IPV6);
438		break;
439	}
440
 
441	skb_set_transport_header(skb, sizeof(struct ipv6hdr));
442	nf_reset_ct(skb);
443
444	return 0;
445}
446
447static int seg6_input_finish(struct net *net, struct sock *sk,
448			     struct sk_buff *skb)
449{
450	return dst_input(skb);
451}
452
453static int seg6_input_core(struct net *net, struct sock *sk,
454			   struct sk_buff *skb)
455{
456	struct dst_entry *orig_dst = skb_dst(skb);
457	struct dst_entry *dst = NULL;
458	struct seg6_lwt *slwt;
459	int err;
460
461	err = seg6_do_srh(skb);
462	if (unlikely(err)) {
463		kfree_skb(skb);
464		return err;
465	}
466
467	slwt = seg6_lwt_lwtunnel(orig_dst->lwtstate);
468
469	preempt_disable();
470	dst = dst_cache_get(&slwt->cache);
471	preempt_enable();
472
 
 
473	if (!dst) {
474		ip6_route_input(skb);
475		dst = skb_dst(skb);
476		if (!dst->error) {
477			preempt_disable();
478			dst_cache_set_ip6(&slwt->cache, dst,
479					  &ipv6_hdr(skb)->saddr);
480			preempt_enable();
481		}
482	} else {
483		skb_dst_drop(skb);
484		skb_dst_set(skb, dst);
485	}
486
487	err = skb_cow_head(skb, LL_RESERVED_SPACE(dst->dev));
488	if (unlikely(err))
489		return err;
490
491	if (static_branch_unlikely(&nf_hooks_lwtunnel_enabled))
492		return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
493			       dev_net(skb->dev), NULL, skb, NULL,
494			       skb_dst(skb)->dev, seg6_input_finish);
495
496	return seg6_input_finish(dev_net(skb->dev), NULL, skb);
497}
498
499static int seg6_input_nf(struct sk_buff *skb)
500{
501	struct net_device *dev = skb_dst(skb)->dev;
502	struct net *net = dev_net(skb->dev);
503
504	switch (skb->protocol) {
505	case htons(ETH_P_IP):
506		return NF_HOOK(NFPROTO_IPV4, NF_INET_POST_ROUTING, net, NULL,
507			       skb, NULL, dev, seg6_input_core);
508	case htons(ETH_P_IPV6):
509		return NF_HOOK(NFPROTO_IPV6, NF_INET_POST_ROUTING, net, NULL,
510			       skb, NULL, dev, seg6_input_core);
511	}
512
513	return -EINVAL;
514}
515
516static int seg6_input(struct sk_buff *skb)
517{
518	if (static_branch_unlikely(&nf_hooks_lwtunnel_enabled))
519		return seg6_input_nf(skb);
520
521	return seg6_input_core(dev_net(skb->dev), NULL, skb);
522}
523
524static int seg6_output_core(struct net *net, struct sock *sk,
525			    struct sk_buff *skb)
526{
527	struct dst_entry *orig_dst = skb_dst(skb);
528	struct dst_entry *dst = NULL;
529	struct seg6_lwt *slwt;
530	int err;
531
532	err = seg6_do_srh(skb);
533	if (unlikely(err))
534		goto drop;
535
536	slwt = seg6_lwt_lwtunnel(orig_dst->lwtstate);
537
538	preempt_disable();
539	dst = dst_cache_get(&slwt->cache);
540	preempt_enable();
541
542	if (unlikely(!dst)) {
543		struct ipv6hdr *hdr = ipv6_hdr(skb);
544		struct flowi6 fl6;
545
546		memset(&fl6, 0, sizeof(fl6));
547		fl6.daddr = hdr->daddr;
548		fl6.saddr = hdr->saddr;
549		fl6.flowlabel = ip6_flowinfo(hdr);
550		fl6.flowi6_mark = skb->mark;
551		fl6.flowi6_proto = hdr->nexthdr;
552
553		dst = ip6_route_output(net, NULL, &fl6);
554		if (dst->error) {
555			err = dst->error;
556			dst_release(dst);
557			goto drop;
558		}
559
560		preempt_disable();
561		dst_cache_set_ip6(&slwt->cache, dst, &fl6.saddr);
562		preempt_enable();
563	}
564
565	skb_dst_drop(skb);
566	skb_dst_set(skb, dst);
567
568	err = skb_cow_head(skb, LL_RESERVED_SPACE(dst->dev));
569	if (unlikely(err))
570		goto drop;
571
572	if (static_branch_unlikely(&nf_hooks_lwtunnel_enabled))
573		return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, net, sk, skb,
574			       NULL, skb_dst(skb)->dev, dst_output);
575
576	return dst_output(net, sk, skb);
577drop:
578	kfree_skb(skb);
579	return err;
580}
581
582static int seg6_output_nf(struct net *net, struct sock *sk, struct sk_buff *skb)
583{
584	struct net_device *dev = skb_dst(skb)->dev;
585
586	switch (skb->protocol) {
587	case htons(ETH_P_IP):
588		return NF_HOOK(NFPROTO_IPV4, NF_INET_POST_ROUTING, net, sk, skb,
589			       NULL, dev, seg6_output_core);
590	case htons(ETH_P_IPV6):
591		return NF_HOOK(NFPROTO_IPV6, NF_INET_POST_ROUTING, net, sk, skb,
592			       NULL, dev, seg6_output_core);
593	}
594
595	return -EINVAL;
596}
597
598static int seg6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
599{
600	if (static_branch_unlikely(&nf_hooks_lwtunnel_enabled))
601		return seg6_output_nf(net, sk, skb);
602
603	return seg6_output_core(net, sk, skb);
604}
605
606static int seg6_build_state(struct net *net, struct nlattr *nla,
607			    unsigned int family, const void *cfg,
608			    struct lwtunnel_state **ts,
609			    struct netlink_ext_ack *extack)
610{
611	struct nlattr *tb[SEG6_IPTUNNEL_MAX + 1];
612	struct seg6_iptunnel_encap *tuninfo;
613	struct lwtunnel_state *newts;
614	int tuninfo_len, min_size;
615	struct seg6_lwt *slwt;
616	int err;
617
618	if (family != AF_INET && family != AF_INET6)
619		return -EINVAL;
620
621	err = nla_parse_nested_deprecated(tb, SEG6_IPTUNNEL_MAX, nla,
622					  seg6_iptunnel_policy, extack);
623
624	if (err < 0)
625		return err;
626
627	if (!tb[SEG6_IPTUNNEL_SRH])
628		return -EINVAL;
629
630	tuninfo = nla_data(tb[SEG6_IPTUNNEL_SRH]);
631	tuninfo_len = nla_len(tb[SEG6_IPTUNNEL_SRH]);
632
633	/* tuninfo must contain at least the iptunnel encap structure,
634	 * the SRH and one segment
635	 */
636	min_size = sizeof(*tuninfo) + sizeof(struct ipv6_sr_hdr) +
637		   sizeof(struct in6_addr);
638	if (tuninfo_len < min_size)
639		return -EINVAL;
640
641	switch (tuninfo->mode) {
642	case SEG6_IPTUN_MODE_INLINE:
643		if (family != AF_INET6)
644			return -EINVAL;
645
646		break;
647	case SEG6_IPTUN_MODE_ENCAP:
648		break;
649	case SEG6_IPTUN_MODE_L2ENCAP:
650		break;
651	case SEG6_IPTUN_MODE_ENCAP_RED:
652		break;
653	case SEG6_IPTUN_MODE_L2ENCAP_RED:
654		break;
655	default:
656		return -EINVAL;
657	}
658
659	/* verify that SRH is consistent */
660	if (!seg6_validate_srh(tuninfo->srh, tuninfo_len - sizeof(*tuninfo), false))
661		return -EINVAL;
662
663	newts = lwtunnel_state_alloc(tuninfo_len + sizeof(*slwt));
664	if (!newts)
665		return -ENOMEM;
666
667	slwt = seg6_lwt_lwtunnel(newts);
668
669	err = dst_cache_init(&slwt->cache, GFP_ATOMIC);
670	if (err) {
671		kfree(newts);
672		return err;
673	}
674
675	memcpy(&slwt->tuninfo, tuninfo, tuninfo_len);
676
677	newts->type = LWTUNNEL_ENCAP_SEG6;
678	newts->flags |= LWTUNNEL_STATE_INPUT_REDIRECT;
679
680	if (tuninfo->mode != SEG6_IPTUN_MODE_L2ENCAP)
681		newts->flags |= LWTUNNEL_STATE_OUTPUT_REDIRECT;
682
683	newts->headroom = seg6_lwt_headroom(tuninfo);
684
685	*ts = newts;
686
687	return 0;
688}
689
690static void seg6_destroy_state(struct lwtunnel_state *lwt)
691{
692	dst_cache_destroy(&seg6_lwt_lwtunnel(lwt)->cache);
693}
694
695static int seg6_fill_encap_info(struct sk_buff *skb,
696				struct lwtunnel_state *lwtstate)
697{
698	struct seg6_iptunnel_encap *tuninfo = seg6_encap_lwtunnel(lwtstate);
699
700	if (nla_put_srh(skb, SEG6_IPTUNNEL_SRH, tuninfo))
701		return -EMSGSIZE;
702
703	return 0;
704}
705
706static int seg6_encap_nlsize(struct lwtunnel_state *lwtstate)
707{
708	struct seg6_iptunnel_encap *tuninfo = seg6_encap_lwtunnel(lwtstate);
709
710	return nla_total_size(SEG6_IPTUN_ENCAP_SIZE(tuninfo));
711}
712
713static int seg6_encap_cmp(struct lwtunnel_state *a, struct lwtunnel_state *b)
714{
715	struct seg6_iptunnel_encap *a_hdr = seg6_encap_lwtunnel(a);
716	struct seg6_iptunnel_encap *b_hdr = seg6_encap_lwtunnel(b);
717	int len = SEG6_IPTUN_ENCAP_SIZE(a_hdr);
718
719	if (len != SEG6_IPTUN_ENCAP_SIZE(b_hdr))
720		return 1;
721
722	return memcmp(a_hdr, b_hdr, len);
723}
724
725static const struct lwtunnel_encap_ops seg6_iptun_ops = {
726	.build_state = seg6_build_state,
727	.destroy_state = seg6_destroy_state,
728	.output = seg6_output,
729	.input = seg6_input,
730	.fill_encap = seg6_fill_encap_info,
731	.get_encap_size = seg6_encap_nlsize,
732	.cmp_encap = seg6_encap_cmp,
733	.owner = THIS_MODULE,
734};
735
736int __init seg6_iptunnel_init(void)
737{
738	return lwtunnel_encap_add_ops(&seg6_iptun_ops, LWTUNNEL_ENCAP_SEG6);
739}
740
741void seg6_iptunnel_exit(void)
742{
743	lwtunnel_encap_del_ops(&seg6_iptun_ops, LWTUNNEL_ENCAP_SEG6);
744}