xref: /openbmc/linux/net/ipv6/ip6_tunnel.c (revision 79e790ff)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *	IPv6 tunneling device
4  *	Linux INET6 implementation
5  *
6  *	Authors:
7  *	Ville Nuorvala		<vnuorval@tcs.hut.fi>
8  *	Yasuyuki Kozakai	<kozakai@linux-ipv6.org>
9  *
10  *      Based on:
11  *      linux/net/ipv6/sit.c and linux/net/ipv4/ipip.c
12  *
13  *      RFC 2473
14  */
15 
16 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
17 
18 #include <linux/module.h>
19 #include <linux/capability.h>
20 #include <linux/errno.h>
21 #include <linux/types.h>
22 #include <linux/sockios.h>
23 #include <linux/icmp.h>
24 #include <linux/if.h>
25 #include <linux/in.h>
26 #include <linux/ip.h>
27 #include <linux/net.h>
28 #include <linux/in6.h>
29 #include <linux/netdevice.h>
30 #include <linux/if_arp.h>
31 #include <linux/icmpv6.h>
32 #include <linux/init.h>
33 #include <linux/route.h>
34 #include <linux/rtnetlink.h>
35 #include <linux/netfilter_ipv6.h>
36 #include <linux/slab.h>
37 #include <linux/hash.h>
38 #include <linux/etherdevice.h>
39 
40 #include <linux/uaccess.h>
41 #include <linux/atomic.h>
42 
43 #include <net/icmp.h>
44 #include <net/ip.h>
45 #include <net/ip_tunnels.h>
46 #include <net/ipv6.h>
47 #include <net/ip6_route.h>
48 #include <net/addrconf.h>
49 #include <net/ip6_tunnel.h>
50 #include <net/xfrm.h>
51 #include <net/dsfield.h>
52 #include <net/inet_ecn.h>
53 #include <net/net_namespace.h>
54 #include <net/netns/generic.h>
55 #include <net/dst_metadata.h>
56 
57 MODULE_AUTHOR("Ville Nuorvala");
58 MODULE_DESCRIPTION("IPv6 tunneling device");
59 MODULE_LICENSE("GPL");
60 MODULE_ALIAS_RTNL_LINK("ip6tnl");
61 MODULE_ALIAS_NETDEV("ip6tnl0");
62 
63 #define IP6_TUNNEL_HASH_SIZE_SHIFT  5
64 #define IP6_TUNNEL_HASH_SIZE (1 << IP6_TUNNEL_HASH_SIZE_SHIFT)
65 
66 static bool log_ecn_error = true;
67 module_param(log_ecn_error, bool, 0644);
68 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
69 
70 static u32 HASH(const struct in6_addr *addr1, const struct in6_addr *addr2)
71 {
72 	u32 hash = ipv6_addr_hash(addr1) ^ ipv6_addr_hash(addr2);
73 
74 	return hash_32(hash, IP6_TUNNEL_HASH_SIZE_SHIFT);
75 }
76 
77 static int ip6_tnl_dev_init(struct net_device *dev);
78 static void ip6_tnl_dev_setup(struct net_device *dev);
79 static struct rtnl_link_ops ip6_link_ops __read_mostly;
80 
81 static unsigned int ip6_tnl_net_id __read_mostly;
82 struct ip6_tnl_net {
83 	/* the IPv6 tunnel fallback device */
84 	struct net_device *fb_tnl_dev;
85 	/* lists for storing tunnels in use */
86 	struct ip6_tnl __rcu *tnls_r_l[IP6_TUNNEL_HASH_SIZE];
87 	struct ip6_tnl __rcu *tnls_wc[1];
88 	struct ip6_tnl __rcu **tnls[2];
89 	struct ip6_tnl __rcu *collect_md_tun;
90 };
91 
92 static inline int ip6_tnl_mpls_supported(void)
93 {
94 	return IS_ENABLED(CONFIG_MPLS);
95 }
96 
97 #define for_each_ip6_tunnel_rcu(start) \
98 	for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
99 
100 /**
101  * ip6_tnl_lookup - fetch tunnel matching the end-point addresses
102  *   @net: network namespace
103  *   @link: ifindex of underlying interface
104  *   @remote: the address of the tunnel exit-point
105  *   @local: the address of the tunnel entry-point
106  *
107  * Return:
108  *   tunnel matching given end-points if found,
109  *   else fallback tunnel if its device is up,
110  *   else %NULL
111  **/
112 
113 static struct ip6_tnl *
114 ip6_tnl_lookup(struct net *net, int link,
115 	       const struct in6_addr *remote, const struct in6_addr *local)
116 {
117 	unsigned int hash = HASH(remote, local);
118 	struct ip6_tnl *t, *cand = NULL;
119 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
120 	struct in6_addr any;
121 
122 	for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
123 		if (!ipv6_addr_equal(local, &t->parms.laddr) ||
124 		    !ipv6_addr_equal(remote, &t->parms.raddr) ||
125 		    !(t->dev->flags & IFF_UP))
126 			continue;
127 
128 		if (link == t->parms.link)
129 			return t;
130 		else
131 			cand = t;
132 	}
133 
134 	memset(&any, 0, sizeof(any));
135 	hash = HASH(&any, local);
136 	for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
137 		if (!ipv6_addr_equal(local, &t->parms.laddr) ||
138 		    !ipv6_addr_any(&t->parms.raddr) ||
139 		    !(t->dev->flags & IFF_UP))
140 			continue;
141 
142 		if (link == t->parms.link)
143 			return t;
144 		else if (!cand)
145 			cand = t;
146 	}
147 
148 	hash = HASH(remote, &any);
149 	for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
150 		if (!ipv6_addr_equal(remote, &t->parms.raddr) ||
151 		    !ipv6_addr_any(&t->parms.laddr) ||
152 		    !(t->dev->flags & IFF_UP))
153 			continue;
154 
155 		if (link == t->parms.link)
156 			return t;
157 		else if (!cand)
158 			cand = t;
159 	}
160 
161 	if (cand)
162 		return cand;
163 
164 	t = rcu_dereference(ip6n->collect_md_tun);
165 	if (t && t->dev->flags & IFF_UP)
166 		return t;
167 
168 	t = rcu_dereference(ip6n->tnls_wc[0]);
169 	if (t && (t->dev->flags & IFF_UP))
170 		return t;
171 
172 	return NULL;
173 }
174 
175 /**
176  * ip6_tnl_bucket - get head of list matching given tunnel parameters
177  *   @ip6n: the private data for ip6_vti in the netns
178  *   @p: parameters containing tunnel end-points
179  *
180  * Description:
181  *   ip6_tnl_bucket() returns the head of the list matching the
182  *   &struct in6_addr entries laddr and raddr in @p.
183  *
184  * Return: head of IPv6 tunnel list
185  **/
186 
187 static struct ip6_tnl __rcu **
188 ip6_tnl_bucket(struct ip6_tnl_net *ip6n, const struct __ip6_tnl_parm *p)
189 {
190 	const struct in6_addr *remote = &p->raddr;
191 	const struct in6_addr *local = &p->laddr;
192 	unsigned int h = 0;
193 	int prio = 0;
194 
195 	if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) {
196 		prio = 1;
197 		h = HASH(remote, local);
198 	}
199 	return &ip6n->tnls[prio][h];
200 }
201 
202 /**
203  * ip6_tnl_link - add tunnel to hash table
204  *   @ip6n: the private data for ip6_vti in the netns
205  *   @t: tunnel to be added
206  **/
207 
208 static void
209 ip6_tnl_link(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
210 {
211 	struct ip6_tnl __rcu **tp = ip6_tnl_bucket(ip6n, &t->parms);
212 
213 	if (t->parms.collect_md)
214 		rcu_assign_pointer(ip6n->collect_md_tun, t);
215 	rcu_assign_pointer(t->next , rtnl_dereference(*tp));
216 	rcu_assign_pointer(*tp, t);
217 }
218 
219 /**
220  * ip6_tnl_unlink - remove tunnel from hash table
221  *   @ip6n: the private data for ip6_vti in the netns
222  *   @t: tunnel to be removed
223  **/
224 
225 static void
226 ip6_tnl_unlink(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
227 {
228 	struct ip6_tnl __rcu **tp;
229 	struct ip6_tnl *iter;
230 
231 	if (t->parms.collect_md)
232 		rcu_assign_pointer(ip6n->collect_md_tun, NULL);
233 
234 	for (tp = ip6_tnl_bucket(ip6n, &t->parms);
235 	     (iter = rtnl_dereference(*tp)) != NULL;
236 	     tp = &iter->next) {
237 		if (t == iter) {
238 			rcu_assign_pointer(*tp, t->next);
239 			break;
240 		}
241 	}
242 }
243 
244 static void ip6_dev_free(struct net_device *dev)
245 {
246 	struct ip6_tnl *t = netdev_priv(dev);
247 
248 	gro_cells_destroy(&t->gro_cells);
249 	dst_cache_destroy(&t->dst_cache);
250 	free_percpu(dev->tstats);
251 }
252 
253 static int ip6_tnl_create2(struct net_device *dev)
254 {
255 	struct ip6_tnl *t = netdev_priv(dev);
256 	struct net *net = dev_net(dev);
257 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
258 	int err;
259 
260 	t = netdev_priv(dev);
261 
262 	dev->rtnl_link_ops = &ip6_link_ops;
263 	err = register_netdevice(dev);
264 	if (err < 0)
265 		goto out;
266 
267 	strcpy(t->parms.name, dev->name);
268 
269 	ip6_tnl_link(ip6n, t);
270 	return 0;
271 
272 out:
273 	return err;
274 }
275 
276 /**
277  * ip6_tnl_create - create a new tunnel
278  *   @net: network namespace
279  *   @p: tunnel parameters
280  *
281  * Description:
282  *   Create tunnel matching given parameters.
283  *
284  * Return:
285  *   created tunnel or error pointer
286  **/
287 
288 static struct ip6_tnl *ip6_tnl_create(struct net *net, struct __ip6_tnl_parm *p)
289 {
290 	struct net_device *dev;
291 	struct ip6_tnl *t;
292 	char name[IFNAMSIZ];
293 	int err = -E2BIG;
294 
295 	if (p->name[0]) {
296 		if (!dev_valid_name(p->name))
297 			goto failed;
298 		strlcpy(name, p->name, IFNAMSIZ);
299 	} else {
300 		sprintf(name, "ip6tnl%%d");
301 	}
302 	err = -ENOMEM;
303 	dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
304 			   ip6_tnl_dev_setup);
305 	if (!dev)
306 		goto failed;
307 
308 	dev_net_set(dev, net);
309 
310 	t = netdev_priv(dev);
311 	t->parms = *p;
312 	t->net = dev_net(dev);
313 	err = ip6_tnl_create2(dev);
314 	if (err < 0)
315 		goto failed_free;
316 
317 	return t;
318 
319 failed_free:
320 	free_netdev(dev);
321 failed:
322 	return ERR_PTR(err);
323 }
324 
325 /**
326  * ip6_tnl_locate - find or create tunnel matching given parameters
327  *   @net: network namespace
328  *   @p: tunnel parameters
329  *   @create: != 0 if allowed to create new tunnel if no match found
330  *
331  * Description:
332  *   ip6_tnl_locate() first tries to locate an existing tunnel
333  *   based on @parms. If this is unsuccessful, but @create is set a new
334  *   tunnel device is created and registered for use.
335  *
336  * Return:
337  *   matching tunnel or error pointer
338  **/
339 
340 static struct ip6_tnl *ip6_tnl_locate(struct net *net,
341 		struct __ip6_tnl_parm *p, int create)
342 {
343 	const struct in6_addr *remote = &p->raddr;
344 	const struct in6_addr *local = &p->laddr;
345 	struct ip6_tnl __rcu **tp;
346 	struct ip6_tnl *t;
347 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
348 
349 	for (tp = ip6_tnl_bucket(ip6n, p);
350 	     (t = rtnl_dereference(*tp)) != NULL;
351 	     tp = &t->next) {
352 		if (ipv6_addr_equal(local, &t->parms.laddr) &&
353 		    ipv6_addr_equal(remote, &t->parms.raddr) &&
354 		    p->link == t->parms.link) {
355 			if (create)
356 				return ERR_PTR(-EEXIST);
357 
358 			return t;
359 		}
360 	}
361 	if (!create)
362 		return ERR_PTR(-ENODEV);
363 	return ip6_tnl_create(net, p);
364 }
365 
366 /**
367  * ip6_tnl_dev_uninit - tunnel device uninitializer
368  *   @dev: the device to be destroyed
369  *
370  * Description:
371  *   ip6_tnl_dev_uninit() removes tunnel from its list
372  **/
373 
374 static void
375 ip6_tnl_dev_uninit(struct net_device *dev)
376 {
377 	struct ip6_tnl *t = netdev_priv(dev);
378 	struct net *net = t->net;
379 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
380 
381 	if (dev == ip6n->fb_tnl_dev)
382 		RCU_INIT_POINTER(ip6n->tnls_wc[0], NULL);
383 	else
384 		ip6_tnl_unlink(ip6n, t);
385 	dst_cache_reset(&t->dst_cache);
386 	dev_put(dev);
387 }
388 
389 /**
390  * ip6_tnl_parse_tlv_enc_lim - handle encapsulation limit option
391  *   @skb: received socket buffer
392  *   @raw: the ICMPv6 error message data
393  *
394  * Return:
395  *   0 if none was found,
396  *   else index to encapsulation limit
397  **/
398 
399 __u16 ip6_tnl_parse_tlv_enc_lim(struct sk_buff *skb, __u8 *raw)
400 {
401 	const struct ipv6hdr *ipv6h = (const struct ipv6hdr *)raw;
402 	unsigned int nhoff = raw - skb->data;
403 	unsigned int off = nhoff + sizeof(*ipv6h);
404 	u8 next, nexthdr = ipv6h->nexthdr;
405 
406 	while (ipv6_ext_hdr(nexthdr) && nexthdr != NEXTHDR_NONE) {
407 		struct ipv6_opt_hdr *hdr;
408 		u16 optlen;
409 
410 		if (!pskb_may_pull(skb, off + sizeof(*hdr)))
411 			break;
412 
413 		hdr = (struct ipv6_opt_hdr *)(skb->data + off);
414 		if (nexthdr == NEXTHDR_FRAGMENT) {
415 			struct frag_hdr *frag_hdr = (struct frag_hdr *) hdr;
416 			if (frag_hdr->frag_off)
417 				break;
418 			optlen = 8;
419 		} else if (nexthdr == NEXTHDR_AUTH) {
420 			optlen = ipv6_authlen(hdr);
421 		} else {
422 			optlen = ipv6_optlen(hdr);
423 		}
424 		/* cache hdr->nexthdr, since pskb_may_pull() might
425 		 * invalidate hdr
426 		 */
427 		next = hdr->nexthdr;
428 		if (nexthdr == NEXTHDR_DEST) {
429 			u16 i = 2;
430 
431 			/* Remember : hdr is no longer valid at this point. */
432 			if (!pskb_may_pull(skb, off + optlen))
433 				break;
434 
435 			while (1) {
436 				struct ipv6_tlv_tnl_enc_lim *tel;
437 
438 				/* No more room for encapsulation limit */
439 				if (i + sizeof(*tel) > optlen)
440 					break;
441 
442 				tel = (struct ipv6_tlv_tnl_enc_lim *)(skb->data + off + i);
443 				/* return index of option if found and valid */
444 				if (tel->type == IPV6_TLV_TNL_ENCAP_LIMIT &&
445 				    tel->length == 1)
446 					return i + off - nhoff;
447 				/* else jump to next option */
448 				if (tel->type)
449 					i += tel->length + 2;
450 				else
451 					i++;
452 			}
453 		}
454 		nexthdr = next;
455 		off += optlen;
456 	}
457 	return 0;
458 }
459 EXPORT_SYMBOL(ip6_tnl_parse_tlv_enc_lim);
460 
461 /* ip6_tnl_err() should handle errors in the tunnel according to the
462  * specifications in RFC 2473.
463  */
464 static int
465 ip6_tnl_err(struct sk_buff *skb, __u8 ipproto, struct inet6_skb_parm *opt,
466 	    u8 *type, u8 *code, int *msg, __u32 *info, int offset)
467 {
468 	const struct ipv6hdr *ipv6h = (const struct ipv6hdr *)skb->data;
469 	struct net *net = dev_net(skb->dev);
470 	u8 rel_type = ICMPV6_DEST_UNREACH;
471 	u8 rel_code = ICMPV6_ADDR_UNREACH;
472 	__u32 rel_info = 0;
473 	struct ip6_tnl *t;
474 	int err = -ENOENT;
475 	int rel_msg = 0;
476 	u8 tproto;
477 	__u16 len;
478 
479 	/* If the packet doesn't contain the original IPv6 header we are
480 	   in trouble since we might need the source address for further
481 	   processing of the error. */
482 
483 	rcu_read_lock();
484 	t = ip6_tnl_lookup(dev_net(skb->dev), skb->dev->ifindex, &ipv6h->daddr, &ipv6h->saddr);
485 	if (!t)
486 		goto out;
487 
488 	tproto = READ_ONCE(t->parms.proto);
489 	if (tproto != ipproto && tproto != 0)
490 		goto out;
491 
492 	err = 0;
493 
494 	switch (*type) {
495 	case ICMPV6_DEST_UNREACH:
496 		net_dbg_ratelimited("%s: Path to destination invalid or inactive!\n",
497 				    t->parms.name);
498 		rel_msg = 1;
499 		break;
500 	case ICMPV6_TIME_EXCEED:
501 		if ((*code) == ICMPV6_EXC_HOPLIMIT) {
502 			net_dbg_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
503 					    t->parms.name);
504 			rel_msg = 1;
505 		}
506 		break;
507 	case ICMPV6_PARAMPROB: {
508 		struct ipv6_tlv_tnl_enc_lim *tel;
509 		__u32 teli;
510 
511 		teli = 0;
512 		if ((*code) == ICMPV6_HDR_FIELD)
513 			teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
514 
515 		if (teli && teli == *info - 2) {
516 			tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
517 			if (tel->encap_limit == 0) {
518 				net_dbg_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
519 						    t->parms.name);
520 				rel_msg = 1;
521 			}
522 		} else {
523 			net_dbg_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
524 					    t->parms.name);
525 		}
526 		break;
527 	}
528 	case ICMPV6_PKT_TOOBIG: {
529 		__u32 mtu;
530 
531 		ip6_update_pmtu(skb, net, htonl(*info), 0, 0,
532 				sock_net_uid(net, NULL));
533 		mtu = *info - offset;
534 		if (mtu < IPV6_MIN_MTU)
535 			mtu = IPV6_MIN_MTU;
536 		len = sizeof(*ipv6h) + ntohs(ipv6h->payload_len);
537 		if (len > mtu) {
538 			rel_type = ICMPV6_PKT_TOOBIG;
539 			rel_code = 0;
540 			rel_info = mtu;
541 			rel_msg = 1;
542 		}
543 		break;
544 	}
545 	case NDISC_REDIRECT:
546 		ip6_redirect(skb, net, skb->dev->ifindex, 0,
547 			     sock_net_uid(net, NULL));
548 		break;
549 	}
550 
551 	*type = rel_type;
552 	*code = rel_code;
553 	*info = rel_info;
554 	*msg = rel_msg;
555 
556 out:
557 	rcu_read_unlock();
558 	return err;
559 }
560 
561 static int
562 ip4ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
563 	   u8 type, u8 code, int offset, __be32 info)
564 {
565 	__u32 rel_info = ntohl(info);
566 	const struct iphdr *eiph;
567 	struct sk_buff *skb2;
568 	int err, rel_msg = 0;
569 	u8 rel_type = type;
570 	u8 rel_code = code;
571 	struct rtable *rt;
572 	struct flowi4 fl4;
573 
574 	err = ip6_tnl_err(skb, IPPROTO_IPIP, opt, &rel_type, &rel_code,
575 			  &rel_msg, &rel_info, offset);
576 	if (err < 0)
577 		return err;
578 
579 	if (rel_msg == 0)
580 		return 0;
581 
582 	switch (rel_type) {
583 	case ICMPV6_DEST_UNREACH:
584 		if (rel_code != ICMPV6_ADDR_UNREACH)
585 			return 0;
586 		rel_type = ICMP_DEST_UNREACH;
587 		rel_code = ICMP_HOST_UNREACH;
588 		break;
589 	case ICMPV6_PKT_TOOBIG:
590 		if (rel_code != 0)
591 			return 0;
592 		rel_type = ICMP_DEST_UNREACH;
593 		rel_code = ICMP_FRAG_NEEDED;
594 		break;
595 	default:
596 		return 0;
597 	}
598 
599 	if (!pskb_may_pull(skb, offset + sizeof(struct iphdr)))
600 		return 0;
601 
602 	skb2 = skb_clone(skb, GFP_ATOMIC);
603 	if (!skb2)
604 		return 0;
605 
606 	skb_dst_drop(skb2);
607 
608 	skb_pull(skb2, offset);
609 	skb_reset_network_header(skb2);
610 	eiph = ip_hdr(skb2);
611 
612 	/* Try to guess incoming interface */
613 	rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL, eiph->saddr,
614 				   0, 0, 0, IPPROTO_IPIP, RT_TOS(eiph->tos), 0);
615 	if (IS_ERR(rt))
616 		goto out;
617 
618 	skb2->dev = rt->dst.dev;
619 	ip_rt_put(rt);
620 
621 	/* route "incoming" packet */
622 	if (rt->rt_flags & RTCF_LOCAL) {
623 		rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL,
624 					   eiph->daddr, eiph->saddr, 0, 0,
625 					   IPPROTO_IPIP, RT_TOS(eiph->tos), 0);
626 		if (IS_ERR(rt) || rt->dst.dev->type != ARPHRD_TUNNEL6) {
627 			if (!IS_ERR(rt))
628 				ip_rt_put(rt);
629 			goto out;
630 		}
631 		skb_dst_set(skb2, &rt->dst);
632 	} else {
633 		if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos,
634 				   skb2->dev) ||
635 		    skb_dst(skb2)->dev->type != ARPHRD_TUNNEL6)
636 			goto out;
637 	}
638 
639 	/* change mtu on this route */
640 	if (rel_type == ICMP_DEST_UNREACH && rel_code == ICMP_FRAG_NEEDED) {
641 		if (rel_info > dst_mtu(skb_dst(skb2)))
642 			goto out;
643 
644 		skb_dst_update_pmtu_no_confirm(skb2, rel_info);
645 	}
646 
647 	icmp_send(skb2, rel_type, rel_code, htonl(rel_info));
648 
649 out:
650 	kfree_skb(skb2);
651 	return 0;
652 }
653 
654 static int
655 ip6ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
656 	   u8 type, u8 code, int offset, __be32 info)
657 {
658 	__u32 rel_info = ntohl(info);
659 	int err, rel_msg = 0;
660 	u8 rel_type = type;
661 	u8 rel_code = code;
662 
663 	err = ip6_tnl_err(skb, IPPROTO_IPV6, opt, &rel_type, &rel_code,
664 			  &rel_msg, &rel_info, offset);
665 	if (err < 0)
666 		return err;
667 
668 	if (rel_msg && pskb_may_pull(skb, offset + sizeof(struct ipv6hdr))) {
669 		struct rt6_info *rt;
670 		struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
671 
672 		if (!skb2)
673 			return 0;
674 
675 		skb_dst_drop(skb2);
676 		skb_pull(skb2, offset);
677 		skb_reset_network_header(skb2);
678 
679 		/* Try to guess incoming interface */
680 		rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr,
681 				NULL, 0, skb2, 0);
682 
683 		if (rt && rt->dst.dev)
684 			skb2->dev = rt->dst.dev;
685 
686 		icmpv6_send(skb2, rel_type, rel_code, rel_info);
687 
688 		ip6_rt_put(rt);
689 
690 		kfree_skb(skb2);
691 	}
692 
693 	return 0;
694 }
695 
696 static int
697 mplsip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
698 	    u8 type, u8 code, int offset, __be32 info)
699 {
700 	__u32 rel_info = ntohl(info);
701 	int err, rel_msg = 0;
702 	u8 rel_type = type;
703 	u8 rel_code = code;
704 
705 	err = ip6_tnl_err(skb, IPPROTO_MPLS, opt, &rel_type, &rel_code,
706 			  &rel_msg, &rel_info, offset);
707 	return err;
708 }
709 
710 static int ip4ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
711 				       const struct ipv6hdr *ipv6h,
712 				       struct sk_buff *skb)
713 {
714 	__u8 dsfield = ipv6_get_dsfield(ipv6h) & ~INET_ECN_MASK;
715 
716 	if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
717 		ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, dsfield);
718 
719 	return IP6_ECN_decapsulate(ipv6h, skb);
720 }
721 
722 static int ip6ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
723 				       const struct ipv6hdr *ipv6h,
724 				       struct sk_buff *skb)
725 {
726 	if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
727 		ipv6_copy_dscp(ipv6_get_dsfield(ipv6h), ipv6_hdr(skb));
728 
729 	return IP6_ECN_decapsulate(ipv6h, skb);
730 }
731 
732 static inline int mplsip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
733 					       const struct ipv6hdr *ipv6h,
734 					       struct sk_buff *skb)
735 {
736 	/* ECN is not supported in AF_MPLS */
737 	return 0;
738 }
739 
740 __u32 ip6_tnl_get_cap(struct ip6_tnl *t,
741 			     const struct in6_addr *laddr,
742 			     const struct in6_addr *raddr)
743 {
744 	struct __ip6_tnl_parm *p = &t->parms;
745 	int ltype = ipv6_addr_type(laddr);
746 	int rtype = ipv6_addr_type(raddr);
747 	__u32 flags = 0;
748 
749 	if (ltype == IPV6_ADDR_ANY || rtype == IPV6_ADDR_ANY) {
750 		flags = IP6_TNL_F_CAP_PER_PACKET;
751 	} else if (ltype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
752 		   rtype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
753 		   !((ltype|rtype) & IPV6_ADDR_LOOPBACK) &&
754 		   (!((ltype|rtype) & IPV6_ADDR_LINKLOCAL) || p->link)) {
755 		if (ltype&IPV6_ADDR_UNICAST)
756 			flags |= IP6_TNL_F_CAP_XMIT;
757 		if (rtype&IPV6_ADDR_UNICAST)
758 			flags |= IP6_TNL_F_CAP_RCV;
759 	}
760 	return flags;
761 }
762 EXPORT_SYMBOL(ip6_tnl_get_cap);
763 
764 /* called with rcu_read_lock() */
765 int ip6_tnl_rcv_ctl(struct ip6_tnl *t,
766 				  const struct in6_addr *laddr,
767 				  const struct in6_addr *raddr)
768 {
769 	struct __ip6_tnl_parm *p = &t->parms;
770 	int ret = 0;
771 	struct net *net = t->net;
772 
773 	if ((p->flags & IP6_TNL_F_CAP_RCV) ||
774 	    ((p->flags & IP6_TNL_F_CAP_PER_PACKET) &&
775 	     (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_RCV))) {
776 		struct net_device *ldev = NULL;
777 
778 		if (p->link)
779 			ldev = dev_get_by_index_rcu(net, p->link);
780 
781 		if ((ipv6_addr_is_multicast(laddr) ||
782 		     likely(ipv6_chk_addr_and_flags(net, laddr, ldev, false,
783 						    0, IFA_F_TENTATIVE))) &&
784 		    ((p->flags & IP6_TNL_F_ALLOW_LOCAL_REMOTE) ||
785 		     likely(!ipv6_chk_addr_and_flags(net, raddr, ldev, true,
786 						     0, IFA_F_TENTATIVE))))
787 			ret = 1;
788 	}
789 	return ret;
790 }
791 EXPORT_SYMBOL_GPL(ip6_tnl_rcv_ctl);
792 
793 static int __ip6_tnl_rcv(struct ip6_tnl *tunnel, struct sk_buff *skb,
794 			 const struct tnl_ptk_info *tpi,
795 			 struct metadata_dst *tun_dst,
796 			 int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
797 						const struct ipv6hdr *ipv6h,
798 						struct sk_buff *skb),
799 			 bool log_ecn_err)
800 {
801 	struct pcpu_sw_netstats *tstats;
802 	const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
803 	int err;
804 
805 	if ((!(tpi->flags & TUNNEL_CSUM) &&
806 	     (tunnel->parms.i_flags & TUNNEL_CSUM)) ||
807 	    ((tpi->flags & TUNNEL_CSUM) &&
808 	     !(tunnel->parms.i_flags & TUNNEL_CSUM))) {
809 		tunnel->dev->stats.rx_crc_errors++;
810 		tunnel->dev->stats.rx_errors++;
811 		goto drop;
812 	}
813 
814 	if (tunnel->parms.i_flags & TUNNEL_SEQ) {
815 		if (!(tpi->flags & TUNNEL_SEQ) ||
816 		    (tunnel->i_seqno &&
817 		     (s32)(ntohl(tpi->seq) - tunnel->i_seqno) < 0)) {
818 			tunnel->dev->stats.rx_fifo_errors++;
819 			tunnel->dev->stats.rx_errors++;
820 			goto drop;
821 		}
822 		tunnel->i_seqno = ntohl(tpi->seq) + 1;
823 	}
824 
825 	skb->protocol = tpi->proto;
826 
827 	/* Warning: All skb pointers will be invalidated! */
828 	if (tunnel->dev->type == ARPHRD_ETHER) {
829 		if (!pskb_may_pull(skb, ETH_HLEN)) {
830 			tunnel->dev->stats.rx_length_errors++;
831 			tunnel->dev->stats.rx_errors++;
832 			goto drop;
833 		}
834 
835 		ipv6h = ipv6_hdr(skb);
836 		skb->protocol = eth_type_trans(skb, tunnel->dev);
837 		skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
838 	} else {
839 		skb->dev = tunnel->dev;
840 	}
841 
842 	skb_reset_network_header(skb);
843 	memset(skb->cb, 0, sizeof(struct inet6_skb_parm));
844 
845 	__skb_tunnel_rx(skb, tunnel->dev, tunnel->net);
846 
847 	err = dscp_ecn_decapsulate(tunnel, ipv6h, skb);
848 	if (unlikely(err)) {
849 		if (log_ecn_err)
850 			net_info_ratelimited("non-ECT from %pI6 with DS=%#x\n",
851 					     &ipv6h->saddr,
852 					     ipv6_get_dsfield(ipv6h));
853 		if (err > 1) {
854 			++tunnel->dev->stats.rx_frame_errors;
855 			++tunnel->dev->stats.rx_errors;
856 			goto drop;
857 		}
858 	}
859 
860 	tstats = this_cpu_ptr(tunnel->dev->tstats);
861 	u64_stats_update_begin(&tstats->syncp);
862 	tstats->rx_packets++;
863 	tstats->rx_bytes += skb->len;
864 	u64_stats_update_end(&tstats->syncp);
865 
866 	skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(tunnel->dev)));
867 
868 	if (tun_dst)
869 		skb_dst_set(skb, (struct dst_entry *)tun_dst);
870 
871 	gro_cells_receive(&tunnel->gro_cells, skb);
872 	return 0;
873 
874 drop:
875 	if (tun_dst)
876 		dst_release((struct dst_entry *)tun_dst);
877 	kfree_skb(skb);
878 	return 0;
879 }
880 
881 int ip6_tnl_rcv(struct ip6_tnl *t, struct sk_buff *skb,
882 		const struct tnl_ptk_info *tpi,
883 		struct metadata_dst *tun_dst,
884 		bool log_ecn_err)
885 {
886 	int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
887 				    const struct ipv6hdr *ipv6h,
888 				    struct sk_buff *skb);
889 
890 	dscp_ecn_decapsulate = ip6ip6_dscp_ecn_decapsulate;
891 	if (tpi->proto == htons(ETH_P_IP))
892 		dscp_ecn_decapsulate = ip4ip6_dscp_ecn_decapsulate;
893 
894 	return __ip6_tnl_rcv(t, skb, tpi, tun_dst, dscp_ecn_decapsulate,
895 			     log_ecn_err);
896 }
897 EXPORT_SYMBOL(ip6_tnl_rcv);
898 
899 static const struct tnl_ptk_info tpi_v6 = {
900 	/* no tunnel info required for ipxip6. */
901 	.proto = htons(ETH_P_IPV6),
902 };
903 
904 static const struct tnl_ptk_info tpi_v4 = {
905 	/* no tunnel info required for ipxip6. */
906 	.proto = htons(ETH_P_IP),
907 };
908 
909 static const struct tnl_ptk_info tpi_mpls = {
910 	/* no tunnel info required for mplsip6. */
911 	.proto = htons(ETH_P_MPLS_UC),
912 };
913 
914 static int ipxip6_rcv(struct sk_buff *skb, u8 ipproto,
915 		      const struct tnl_ptk_info *tpi,
916 		      int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
917 						  const struct ipv6hdr *ipv6h,
918 						  struct sk_buff *skb))
919 {
920 	struct ip6_tnl *t;
921 	const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
922 	struct metadata_dst *tun_dst = NULL;
923 	int ret = -1;
924 
925 	rcu_read_lock();
926 	t = ip6_tnl_lookup(dev_net(skb->dev), skb->dev->ifindex, &ipv6h->saddr, &ipv6h->daddr);
927 
928 	if (t) {
929 		u8 tproto = READ_ONCE(t->parms.proto);
930 
931 		if (tproto != ipproto && tproto != 0)
932 			goto drop;
933 		if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
934 			goto drop;
935 		ipv6h = ipv6_hdr(skb);
936 		if (!ip6_tnl_rcv_ctl(t, &ipv6h->daddr, &ipv6h->saddr))
937 			goto drop;
938 		if (iptunnel_pull_header(skb, 0, tpi->proto, false))
939 			goto drop;
940 		if (t->parms.collect_md) {
941 			tun_dst = ipv6_tun_rx_dst(skb, 0, 0, 0);
942 			if (!tun_dst)
943 				goto drop;
944 		}
945 		ret = __ip6_tnl_rcv(t, skb, tpi, tun_dst, dscp_ecn_decapsulate,
946 				    log_ecn_error);
947 	}
948 
949 	rcu_read_unlock();
950 
951 	return ret;
952 
953 drop:
954 	rcu_read_unlock();
955 	kfree_skb(skb);
956 	return 0;
957 }
958 
959 static int ip4ip6_rcv(struct sk_buff *skb)
960 {
961 	return ipxip6_rcv(skb, IPPROTO_IPIP, &tpi_v4,
962 			  ip4ip6_dscp_ecn_decapsulate);
963 }
964 
965 static int ip6ip6_rcv(struct sk_buff *skb)
966 {
967 	return ipxip6_rcv(skb, IPPROTO_IPV6, &tpi_v6,
968 			  ip6ip6_dscp_ecn_decapsulate);
969 }
970 
971 static int mplsip6_rcv(struct sk_buff *skb)
972 {
973 	return ipxip6_rcv(skb, IPPROTO_MPLS, &tpi_mpls,
974 			  mplsip6_dscp_ecn_decapsulate);
975 }
976 
977 struct ipv6_tel_txoption {
978 	struct ipv6_txoptions ops;
979 	__u8 dst_opt[8];
980 };
981 
982 static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit)
983 {
984 	memset(opt, 0, sizeof(struct ipv6_tel_txoption));
985 
986 	opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT;
987 	opt->dst_opt[3] = 1;
988 	opt->dst_opt[4] = encap_limit;
989 	opt->dst_opt[5] = IPV6_TLV_PADN;
990 	opt->dst_opt[6] = 1;
991 
992 	opt->ops.dst1opt = (struct ipv6_opt_hdr *) opt->dst_opt;
993 	opt->ops.opt_nflen = 8;
994 }
995 
996 /**
997  * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
998  *   @t: the outgoing tunnel device
999  *   @hdr: IPv6 header from the incoming packet
1000  *
1001  * Description:
1002  *   Avoid trivial tunneling loop by checking that tunnel exit-point
1003  *   doesn't match source of incoming packet.
1004  *
1005  * Return:
1006  *   1 if conflict,
1007  *   0 else
1008  **/
1009 
1010 static inline bool
1011 ip6_tnl_addr_conflict(const struct ip6_tnl *t, const struct ipv6hdr *hdr)
1012 {
1013 	return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
1014 }
1015 
1016 int ip6_tnl_xmit_ctl(struct ip6_tnl *t,
1017 		     const struct in6_addr *laddr,
1018 		     const struct in6_addr *raddr)
1019 {
1020 	struct __ip6_tnl_parm *p = &t->parms;
1021 	int ret = 0;
1022 	struct net *net = t->net;
1023 
1024 	if (t->parms.collect_md)
1025 		return 1;
1026 
1027 	if ((p->flags & IP6_TNL_F_CAP_XMIT) ||
1028 	    ((p->flags & IP6_TNL_F_CAP_PER_PACKET) &&
1029 	     (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_XMIT))) {
1030 		struct net_device *ldev = NULL;
1031 
1032 		rcu_read_lock();
1033 		if (p->link)
1034 			ldev = dev_get_by_index_rcu(net, p->link);
1035 
1036 		if (unlikely(!ipv6_chk_addr_and_flags(net, laddr, ldev, false,
1037 						      0, IFA_F_TENTATIVE)))
1038 			pr_warn("%s xmit: Local address not yet configured!\n",
1039 				p->name);
1040 		else if (!(p->flags & IP6_TNL_F_ALLOW_LOCAL_REMOTE) &&
1041 			 !ipv6_addr_is_multicast(raddr) &&
1042 			 unlikely(ipv6_chk_addr_and_flags(net, raddr, ldev,
1043 							  true, 0, IFA_F_TENTATIVE)))
1044 			pr_warn("%s xmit: Routing loop! Remote address found on this node!\n",
1045 				p->name);
1046 		else
1047 			ret = 1;
1048 		rcu_read_unlock();
1049 	}
1050 	return ret;
1051 }
1052 EXPORT_SYMBOL_GPL(ip6_tnl_xmit_ctl);
1053 
1054 /**
1055  * ip6_tnl_xmit - encapsulate packet and send
1056  *   @skb: the outgoing socket buffer
1057  *   @dev: the outgoing tunnel device
1058  *   @dsfield: dscp code for outer header
1059  *   @fl6: flow of tunneled packet
1060  *   @encap_limit: encapsulation limit
1061  *   @pmtu: Path MTU is stored if packet is too big
1062  *   @proto: next header value
1063  *
1064  * Description:
1065  *   Build new header and do some sanity checks on the packet before sending
1066  *   it.
1067  *
1068  * Return:
1069  *   0 on success
1070  *   -1 fail
1071  *   %-EMSGSIZE message too big. return mtu in this case.
1072  **/
1073 
1074 int ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev, __u8 dsfield,
1075 		 struct flowi6 *fl6, int encap_limit, __u32 *pmtu,
1076 		 __u8 proto)
1077 {
1078 	struct ip6_tnl *t = netdev_priv(dev);
1079 	struct net *net = t->net;
1080 	struct net_device_stats *stats = &t->dev->stats;
1081 	struct ipv6hdr *ipv6h;
1082 	struct ipv6_tel_txoption opt;
1083 	struct dst_entry *dst = NULL, *ndst = NULL;
1084 	struct net_device *tdev;
1085 	int mtu;
1086 	unsigned int eth_hlen = t->dev->type == ARPHRD_ETHER ? ETH_HLEN : 0;
1087 	unsigned int psh_hlen = sizeof(struct ipv6hdr) + t->encap_hlen;
1088 	unsigned int max_headroom = psh_hlen;
1089 	bool use_cache = false;
1090 	u8 hop_limit;
1091 	int err = -1;
1092 
1093 	if (t->parms.collect_md) {
1094 		hop_limit = skb_tunnel_info(skb)->key.ttl;
1095 		goto route_lookup;
1096 	} else {
1097 		hop_limit = t->parms.hop_limit;
1098 	}
1099 
1100 	/* NBMA tunnel */
1101 	if (ipv6_addr_any(&t->parms.raddr)) {
1102 		if (skb->protocol == htons(ETH_P_IPV6)) {
1103 			struct in6_addr *addr6;
1104 			struct neighbour *neigh;
1105 			int addr_type;
1106 
1107 			if (!skb_dst(skb))
1108 				goto tx_err_link_failure;
1109 
1110 			neigh = dst_neigh_lookup(skb_dst(skb),
1111 						 &ipv6_hdr(skb)->daddr);
1112 			if (!neigh)
1113 				goto tx_err_link_failure;
1114 
1115 			addr6 = (struct in6_addr *)&neigh->primary_key;
1116 			addr_type = ipv6_addr_type(addr6);
1117 
1118 			if (addr_type == IPV6_ADDR_ANY)
1119 				addr6 = &ipv6_hdr(skb)->daddr;
1120 
1121 			memcpy(&fl6->daddr, addr6, sizeof(fl6->daddr));
1122 			neigh_release(neigh);
1123 		}
1124 	} else if (t->parms.proto != 0 && !(t->parms.flags &
1125 					    (IP6_TNL_F_USE_ORIG_TCLASS |
1126 					     IP6_TNL_F_USE_ORIG_FWMARK))) {
1127 		/* enable the cache only if neither the outer protocol nor the
1128 		 * routing decision depends on the current inner header value
1129 		 */
1130 		use_cache = true;
1131 	}
1132 
1133 	if (use_cache)
1134 		dst = dst_cache_get(&t->dst_cache);
1135 
1136 	if (!ip6_tnl_xmit_ctl(t, &fl6->saddr, &fl6->daddr))
1137 		goto tx_err_link_failure;
1138 
1139 	if (!dst) {
1140 route_lookup:
1141 		/* add dsfield to flowlabel for route lookup */
1142 		fl6->flowlabel = ip6_make_flowinfo(dsfield, fl6->flowlabel);
1143 
1144 		dst = ip6_route_output(net, NULL, fl6);
1145 
1146 		if (dst->error)
1147 			goto tx_err_link_failure;
1148 		dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), NULL, 0);
1149 		if (IS_ERR(dst)) {
1150 			err = PTR_ERR(dst);
1151 			dst = NULL;
1152 			goto tx_err_link_failure;
1153 		}
1154 		if (t->parms.collect_md && ipv6_addr_any(&fl6->saddr) &&
1155 		    ipv6_dev_get_saddr(net, ip6_dst_idev(dst)->dev,
1156 				       &fl6->daddr, 0, &fl6->saddr))
1157 			goto tx_err_link_failure;
1158 		ndst = dst;
1159 	}
1160 
1161 	tdev = dst->dev;
1162 
1163 	if (tdev == dev) {
1164 		stats->collisions++;
1165 		net_warn_ratelimited("%s: Local routing loop detected!\n",
1166 				     t->parms.name);
1167 		goto tx_err_dst_release;
1168 	}
1169 	mtu = dst_mtu(dst) - eth_hlen - psh_hlen - t->tun_hlen;
1170 	if (encap_limit >= 0) {
1171 		max_headroom += 8;
1172 		mtu -= 8;
1173 	}
1174 	mtu = max(mtu, skb->protocol == htons(ETH_P_IPV6) ?
1175 		       IPV6_MIN_MTU : IPV4_MIN_MTU);
1176 
1177 	skb_dst_update_pmtu_no_confirm(skb, mtu);
1178 	if (skb->len - t->tun_hlen - eth_hlen > mtu && !skb_is_gso(skb)) {
1179 		*pmtu = mtu;
1180 		err = -EMSGSIZE;
1181 		goto tx_err_dst_release;
1182 	}
1183 
1184 	if (t->err_count > 0) {
1185 		if (time_before(jiffies,
1186 				t->err_time + IP6TUNNEL_ERR_TIMEO)) {
1187 			t->err_count--;
1188 
1189 			dst_link_failure(skb);
1190 		} else {
1191 			t->err_count = 0;
1192 		}
1193 	}
1194 
1195 	skb_scrub_packet(skb, !net_eq(t->net, dev_net(dev)));
1196 
1197 	/*
1198 	 * Okay, now see if we can stuff it in the buffer as-is.
1199 	 */
1200 	max_headroom += LL_RESERVED_SPACE(tdev);
1201 
1202 	if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
1203 	    (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
1204 		struct sk_buff *new_skb;
1205 
1206 		new_skb = skb_realloc_headroom(skb, max_headroom);
1207 		if (!new_skb)
1208 			goto tx_err_dst_release;
1209 
1210 		if (skb->sk)
1211 			skb_set_owner_w(new_skb, skb->sk);
1212 		consume_skb(skb);
1213 		skb = new_skb;
1214 	}
1215 
1216 	if (t->parms.collect_md) {
1217 		if (t->encap.type != TUNNEL_ENCAP_NONE)
1218 			goto tx_err_dst_release;
1219 	} else {
1220 		if (use_cache && ndst)
1221 			dst_cache_set_ip6(&t->dst_cache, ndst, &fl6->saddr);
1222 	}
1223 	skb_dst_set(skb, dst);
1224 
1225 	if (hop_limit == 0) {
1226 		if (skb->protocol == htons(ETH_P_IP))
1227 			hop_limit = ip_hdr(skb)->ttl;
1228 		else if (skb->protocol == htons(ETH_P_IPV6))
1229 			hop_limit = ipv6_hdr(skb)->hop_limit;
1230 		else
1231 			hop_limit = ip6_dst_hoplimit(dst);
1232 	}
1233 
1234 	/* Calculate max headroom for all the headers and adjust
1235 	 * needed_headroom if necessary.
1236 	 */
1237 	max_headroom = LL_RESERVED_SPACE(dst->dev) + sizeof(struct ipv6hdr)
1238 			+ dst->header_len + t->hlen;
1239 	if (max_headroom > dev->needed_headroom)
1240 		dev->needed_headroom = max_headroom;
1241 
1242 	skb_set_inner_ipproto(skb, proto);
1243 
1244 	err = ip6_tnl_encap(skb, t, &proto, fl6);
1245 	if (err)
1246 		return err;
1247 
1248 	if (encap_limit >= 0) {
1249 		init_tel_txopt(&opt, encap_limit);
1250 		ipv6_push_frag_opts(skb, &opt.ops, &proto);
1251 	}
1252 
1253 	skb_push(skb, sizeof(struct ipv6hdr));
1254 	skb_reset_network_header(skb);
1255 	ipv6h = ipv6_hdr(skb);
1256 	ip6_flow_hdr(ipv6h, dsfield,
1257 		     ip6_make_flowlabel(net, skb, fl6->flowlabel, true, fl6));
1258 	ipv6h->hop_limit = hop_limit;
1259 	ipv6h->nexthdr = proto;
1260 	ipv6h->saddr = fl6->saddr;
1261 	ipv6h->daddr = fl6->daddr;
1262 	ip6tunnel_xmit(NULL, skb, dev);
1263 	return 0;
1264 tx_err_link_failure:
1265 	stats->tx_carrier_errors++;
1266 	dst_link_failure(skb);
1267 tx_err_dst_release:
1268 	dst_release(dst);
1269 	return err;
1270 }
1271 EXPORT_SYMBOL(ip6_tnl_xmit);
1272 
1273 static inline int
1274 ipxip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev,
1275 		u8 protocol)
1276 {
1277 	struct ip6_tnl *t = netdev_priv(dev);
1278 	struct ipv6hdr *ipv6h;
1279 	const struct iphdr  *iph;
1280 	int encap_limit = -1;
1281 	__u16 offset;
1282 	struct flowi6 fl6;
1283 	__u8 dsfield, orig_dsfield;
1284 	__u32 mtu;
1285 	u8 tproto;
1286 	int err;
1287 
1288 	tproto = READ_ONCE(t->parms.proto);
1289 	if (tproto != protocol && tproto != 0)
1290 		return -1;
1291 
1292 	if (t->parms.collect_md) {
1293 		struct ip_tunnel_info *tun_info;
1294 		const struct ip_tunnel_key *key;
1295 
1296 		tun_info = skb_tunnel_info(skb);
1297 		if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
1298 			     ip_tunnel_info_af(tun_info) != AF_INET6))
1299 			return -1;
1300 		key = &tun_info->key;
1301 		memset(&fl6, 0, sizeof(fl6));
1302 		fl6.flowi6_proto = protocol;
1303 		fl6.saddr = key->u.ipv6.src;
1304 		fl6.daddr = key->u.ipv6.dst;
1305 		fl6.flowlabel = key->label;
1306 		dsfield =  key->tos;
1307 		switch (protocol) {
1308 		case IPPROTO_IPIP:
1309 			iph = ip_hdr(skb);
1310 			orig_dsfield = ipv4_get_dsfield(iph);
1311 			break;
1312 		case IPPROTO_IPV6:
1313 			ipv6h = ipv6_hdr(skb);
1314 			orig_dsfield = ipv6_get_dsfield(ipv6h);
1315 			break;
1316 		default:
1317 			orig_dsfield = dsfield;
1318 			break;
1319 		}
1320 	} else {
1321 		if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1322 			encap_limit = t->parms.encap_limit;
1323 		if (protocol == IPPROTO_IPV6) {
1324 			offset = ip6_tnl_parse_tlv_enc_lim(skb,
1325 						skb_network_header(skb));
1326 			/* ip6_tnl_parse_tlv_enc_lim() might have
1327 			 * reallocated skb->head
1328 			 */
1329 			if (offset > 0) {
1330 				struct ipv6_tlv_tnl_enc_lim *tel;
1331 
1332 				tel = (void *)&skb_network_header(skb)[offset];
1333 				if (tel->encap_limit == 0) {
1334 					icmpv6_ndo_send(skb, ICMPV6_PARAMPROB,
1335 							ICMPV6_HDR_FIELD, offset + 2);
1336 					return -1;
1337 				}
1338 				encap_limit = tel->encap_limit - 1;
1339 			}
1340 		}
1341 
1342 		memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
1343 		fl6.flowi6_proto = protocol;
1344 
1345 		if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
1346 			fl6.flowi6_mark = skb->mark;
1347 		else
1348 			fl6.flowi6_mark = t->parms.fwmark;
1349 		switch (protocol) {
1350 		case IPPROTO_IPIP:
1351 			iph = ip_hdr(skb);
1352 			orig_dsfield = ipv4_get_dsfield(iph);
1353 			if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1354 				dsfield = orig_dsfield;
1355 			else
1356 				dsfield = ip6_tclass(t->parms.flowinfo);
1357 			break;
1358 		case IPPROTO_IPV6:
1359 			ipv6h = ipv6_hdr(skb);
1360 			orig_dsfield = ipv6_get_dsfield(ipv6h);
1361 			if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1362 				dsfield = orig_dsfield;
1363 			else
1364 				dsfield = ip6_tclass(t->parms.flowinfo);
1365 			if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
1366 				fl6.flowlabel |= ip6_flowlabel(ipv6h);
1367 			break;
1368 		default:
1369 			orig_dsfield = dsfield = ip6_tclass(t->parms.flowinfo);
1370 			break;
1371 		}
1372 	}
1373 
1374 	fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
1375 	dsfield = INET_ECN_encapsulate(dsfield, orig_dsfield);
1376 
1377 	if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP6))
1378 		return -1;
1379 
1380 	err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
1381 			   protocol);
1382 	if (err != 0) {
1383 		/* XXX: send ICMP error even if DF is not set. */
1384 		if (err == -EMSGSIZE)
1385 			switch (protocol) {
1386 			case IPPROTO_IPIP:
1387 				icmp_ndo_send(skb, ICMP_DEST_UNREACH,
1388 					      ICMP_FRAG_NEEDED, htonl(mtu));
1389 				break;
1390 			case IPPROTO_IPV6:
1391 				icmpv6_ndo_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
1392 				break;
1393 			default:
1394 				break;
1395 			}
1396 		return -1;
1397 	}
1398 
1399 	return 0;
1400 }
1401 
1402 static netdev_tx_t
1403 ip6_tnl_start_xmit(struct sk_buff *skb, struct net_device *dev)
1404 {
1405 	struct ip6_tnl *t = netdev_priv(dev);
1406 	struct net_device_stats *stats = &t->dev->stats;
1407 	u8 ipproto;
1408 	int ret;
1409 
1410 	if (!pskb_inet_may_pull(skb))
1411 		goto tx_err;
1412 
1413 	switch (skb->protocol) {
1414 	case htons(ETH_P_IP):
1415 		ipproto = IPPROTO_IPIP;
1416 		break;
1417 	case htons(ETH_P_IPV6):
1418 		if (ip6_tnl_addr_conflict(t, ipv6_hdr(skb)))
1419 			goto tx_err;
1420 		ipproto = IPPROTO_IPV6;
1421 		break;
1422 	case htons(ETH_P_MPLS_UC):
1423 		ipproto = IPPROTO_MPLS;
1424 		break;
1425 	default:
1426 		goto tx_err;
1427 	}
1428 
1429 	ret = ipxip6_tnl_xmit(skb, dev, ipproto);
1430 	if (ret < 0)
1431 		goto tx_err;
1432 
1433 	return NETDEV_TX_OK;
1434 
1435 tx_err:
1436 	stats->tx_errors++;
1437 	stats->tx_dropped++;
1438 	kfree_skb(skb);
1439 	return NETDEV_TX_OK;
1440 }
1441 
1442 static void ip6_tnl_link_config(struct ip6_tnl *t)
1443 {
1444 	struct net_device *dev = t->dev;
1445 	struct net_device *tdev = NULL;
1446 	struct __ip6_tnl_parm *p = &t->parms;
1447 	struct flowi6 *fl6 = &t->fl.u.ip6;
1448 	unsigned int mtu;
1449 	int t_hlen;
1450 
1451 	memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
1452 	memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
1453 
1454 	/* Set up flowi template */
1455 	fl6->saddr = p->laddr;
1456 	fl6->daddr = p->raddr;
1457 	fl6->flowi6_oif = p->link;
1458 	fl6->flowlabel = 0;
1459 
1460 	if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
1461 		fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
1462 	if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
1463 		fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
1464 
1465 	p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
1466 	p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
1467 
1468 	if (p->flags&IP6_TNL_F_CAP_XMIT && p->flags&IP6_TNL_F_CAP_RCV)
1469 		dev->flags |= IFF_POINTOPOINT;
1470 	else
1471 		dev->flags &= ~IFF_POINTOPOINT;
1472 
1473 	t->tun_hlen = 0;
1474 	t->hlen = t->encap_hlen + t->tun_hlen;
1475 	t_hlen = t->hlen + sizeof(struct ipv6hdr);
1476 
1477 	if (p->flags & IP6_TNL_F_CAP_XMIT) {
1478 		int strict = (ipv6_addr_type(&p->raddr) &
1479 			      (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
1480 
1481 		struct rt6_info *rt = rt6_lookup(t->net,
1482 						 &p->raddr, &p->laddr,
1483 						 p->link, NULL, strict);
1484 		if (rt) {
1485 			tdev = rt->dst.dev;
1486 			ip6_rt_put(rt);
1487 		}
1488 
1489 		if (!tdev && p->link)
1490 			tdev = __dev_get_by_index(t->net, p->link);
1491 
1492 		if (tdev) {
1493 			dev->hard_header_len = tdev->hard_header_len + t_hlen;
1494 			mtu = min_t(unsigned int, tdev->mtu, IP6_MAX_MTU);
1495 
1496 			dev->mtu = mtu - t_hlen;
1497 			if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1498 				dev->mtu -= 8;
1499 
1500 			if (dev->mtu < IPV6_MIN_MTU)
1501 				dev->mtu = IPV6_MIN_MTU;
1502 		}
1503 	}
1504 }
1505 
1506 /**
1507  * ip6_tnl_change - update the tunnel parameters
1508  *   @t: tunnel to be changed
1509  *   @p: tunnel configuration parameters
1510  *
1511  * Description:
1512  *   ip6_tnl_change() updates the tunnel parameters
1513  **/
1514 
1515 static int
1516 ip6_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p)
1517 {
1518 	t->parms.laddr = p->laddr;
1519 	t->parms.raddr = p->raddr;
1520 	t->parms.flags = p->flags;
1521 	t->parms.hop_limit = p->hop_limit;
1522 	t->parms.encap_limit = p->encap_limit;
1523 	t->parms.flowinfo = p->flowinfo;
1524 	t->parms.link = p->link;
1525 	t->parms.proto = p->proto;
1526 	t->parms.fwmark = p->fwmark;
1527 	dst_cache_reset(&t->dst_cache);
1528 	ip6_tnl_link_config(t);
1529 	return 0;
1530 }
1531 
1532 static int ip6_tnl_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
1533 {
1534 	struct net *net = t->net;
1535 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1536 	int err;
1537 
1538 	ip6_tnl_unlink(ip6n, t);
1539 	synchronize_net();
1540 	err = ip6_tnl_change(t, p);
1541 	ip6_tnl_link(ip6n, t);
1542 	netdev_state_change(t->dev);
1543 	return err;
1544 }
1545 
1546 static int ip6_tnl0_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
1547 {
1548 	/* for default tnl0 device allow to change only the proto */
1549 	t->parms.proto = p->proto;
1550 	netdev_state_change(t->dev);
1551 	return 0;
1552 }
1553 
1554 static void
1555 ip6_tnl_parm_from_user(struct __ip6_tnl_parm *p, const struct ip6_tnl_parm *u)
1556 {
1557 	p->laddr = u->laddr;
1558 	p->raddr = u->raddr;
1559 	p->flags = u->flags;
1560 	p->hop_limit = u->hop_limit;
1561 	p->encap_limit = u->encap_limit;
1562 	p->flowinfo = u->flowinfo;
1563 	p->link = u->link;
1564 	p->proto = u->proto;
1565 	memcpy(p->name, u->name, sizeof(u->name));
1566 }
1567 
1568 static void
1569 ip6_tnl_parm_to_user(struct ip6_tnl_parm *u, const struct __ip6_tnl_parm *p)
1570 {
1571 	u->laddr = p->laddr;
1572 	u->raddr = p->raddr;
1573 	u->flags = p->flags;
1574 	u->hop_limit = p->hop_limit;
1575 	u->encap_limit = p->encap_limit;
1576 	u->flowinfo = p->flowinfo;
1577 	u->link = p->link;
1578 	u->proto = p->proto;
1579 	memcpy(u->name, p->name, sizeof(u->name));
1580 }
1581 
1582 /**
1583  * ip6_tnl_ioctl - configure ipv6 tunnels from userspace
1584  *   @dev: virtual device associated with tunnel
1585  *   @ifr: parameters passed from userspace
1586  *   @cmd: command to be performed
1587  *
1588  * Description:
1589  *   ip6_tnl_ioctl() is used for managing IPv6 tunnels
1590  *   from userspace.
1591  *
1592  *   The possible commands are the following:
1593  *     %SIOCGETTUNNEL: get tunnel parameters for device
1594  *     %SIOCADDTUNNEL: add tunnel matching given tunnel parameters
1595  *     %SIOCCHGTUNNEL: change tunnel parameters to those given
1596  *     %SIOCDELTUNNEL: delete tunnel
1597  *
1598  *   The fallback device "ip6tnl0", created during module
1599  *   initialization, can be used for creating other tunnel devices.
1600  *
1601  * Return:
1602  *   0 on success,
1603  *   %-EFAULT if unable to copy data to or from userspace,
1604  *   %-EPERM if current process hasn't %CAP_NET_ADMIN set
1605  *   %-EINVAL if passed tunnel parameters are invalid,
1606  *   %-EEXIST if changing a tunnel's parameters would cause a conflict
1607  *   %-ENODEV if attempting to change or delete a nonexisting device
1608  **/
1609 
1610 static int
1611 ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1612 {
1613 	int err = 0;
1614 	struct ip6_tnl_parm p;
1615 	struct __ip6_tnl_parm p1;
1616 	struct ip6_tnl *t = netdev_priv(dev);
1617 	struct net *net = t->net;
1618 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1619 
1620 	memset(&p1, 0, sizeof(p1));
1621 
1622 	switch (cmd) {
1623 	case SIOCGETTUNNEL:
1624 		if (dev == ip6n->fb_tnl_dev) {
1625 			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1626 				err = -EFAULT;
1627 				break;
1628 			}
1629 			ip6_tnl_parm_from_user(&p1, &p);
1630 			t = ip6_tnl_locate(net, &p1, 0);
1631 			if (IS_ERR(t))
1632 				t = netdev_priv(dev);
1633 		} else {
1634 			memset(&p, 0, sizeof(p));
1635 		}
1636 		ip6_tnl_parm_to_user(&p, &t->parms);
1637 		if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) {
1638 			err = -EFAULT;
1639 		}
1640 		break;
1641 	case SIOCADDTUNNEL:
1642 	case SIOCCHGTUNNEL:
1643 		err = -EPERM;
1644 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1645 			break;
1646 		err = -EFAULT;
1647 		if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1648 			break;
1649 		err = -EINVAL;
1650 		if (p.proto != IPPROTO_IPV6 && p.proto != IPPROTO_IPIP &&
1651 		    p.proto != 0)
1652 			break;
1653 		ip6_tnl_parm_from_user(&p1, &p);
1654 		t = ip6_tnl_locate(net, &p1, cmd == SIOCADDTUNNEL);
1655 		if (cmd == SIOCCHGTUNNEL) {
1656 			if (!IS_ERR(t)) {
1657 				if (t->dev != dev) {
1658 					err = -EEXIST;
1659 					break;
1660 				}
1661 			} else
1662 				t = netdev_priv(dev);
1663 			if (dev == ip6n->fb_tnl_dev)
1664 				err = ip6_tnl0_update(t, &p1);
1665 			else
1666 				err = ip6_tnl_update(t, &p1);
1667 		}
1668 		if (!IS_ERR(t)) {
1669 			err = 0;
1670 			ip6_tnl_parm_to_user(&p, &t->parms);
1671 			if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1672 				err = -EFAULT;
1673 
1674 		} else {
1675 			err = PTR_ERR(t);
1676 		}
1677 		break;
1678 	case SIOCDELTUNNEL:
1679 		err = -EPERM;
1680 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1681 			break;
1682 
1683 		if (dev == ip6n->fb_tnl_dev) {
1684 			err = -EFAULT;
1685 			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1686 				break;
1687 			err = -ENOENT;
1688 			ip6_tnl_parm_from_user(&p1, &p);
1689 			t = ip6_tnl_locate(net, &p1, 0);
1690 			if (IS_ERR(t))
1691 				break;
1692 			err = -EPERM;
1693 			if (t->dev == ip6n->fb_tnl_dev)
1694 				break;
1695 			dev = t->dev;
1696 		}
1697 		err = 0;
1698 		unregister_netdevice(dev);
1699 		break;
1700 	default:
1701 		err = -EINVAL;
1702 	}
1703 	return err;
1704 }
1705 
1706 /**
1707  * ip6_tnl_change_mtu - change mtu manually for tunnel device
1708  *   @dev: virtual device associated with tunnel
1709  *   @new_mtu: the new mtu
1710  *
1711  * Return:
1712  *   0 on success,
1713  *   %-EINVAL if mtu too small
1714  **/
1715 
1716 int ip6_tnl_change_mtu(struct net_device *dev, int new_mtu)
1717 {
1718 	struct ip6_tnl *tnl = netdev_priv(dev);
1719 
1720 	if (tnl->parms.proto == IPPROTO_IPV6) {
1721 		if (new_mtu < IPV6_MIN_MTU)
1722 			return -EINVAL;
1723 	} else {
1724 		if (new_mtu < ETH_MIN_MTU)
1725 			return -EINVAL;
1726 	}
1727 	if (tnl->parms.proto == IPPROTO_IPV6 || tnl->parms.proto == 0) {
1728 		if (new_mtu > IP6_MAX_MTU - dev->hard_header_len)
1729 			return -EINVAL;
1730 	} else {
1731 		if (new_mtu > IP_MAX_MTU - dev->hard_header_len)
1732 			return -EINVAL;
1733 	}
1734 	dev->mtu = new_mtu;
1735 	return 0;
1736 }
1737 EXPORT_SYMBOL(ip6_tnl_change_mtu);
1738 
1739 int ip6_tnl_get_iflink(const struct net_device *dev)
1740 {
1741 	struct ip6_tnl *t = netdev_priv(dev);
1742 
1743 	return t->parms.link;
1744 }
1745 EXPORT_SYMBOL(ip6_tnl_get_iflink);
1746 
1747 int ip6_tnl_encap_add_ops(const struct ip6_tnl_encap_ops *ops,
1748 			  unsigned int num)
1749 {
1750 	if (num >= MAX_IPTUN_ENCAP_OPS)
1751 		return -ERANGE;
1752 
1753 	return !cmpxchg((const struct ip6_tnl_encap_ops **)
1754 			&ip6tun_encaps[num],
1755 			NULL, ops) ? 0 : -1;
1756 }
1757 EXPORT_SYMBOL(ip6_tnl_encap_add_ops);
1758 
1759 int ip6_tnl_encap_del_ops(const struct ip6_tnl_encap_ops *ops,
1760 			  unsigned int num)
1761 {
1762 	int ret;
1763 
1764 	if (num >= MAX_IPTUN_ENCAP_OPS)
1765 		return -ERANGE;
1766 
1767 	ret = (cmpxchg((const struct ip6_tnl_encap_ops **)
1768 		       &ip6tun_encaps[num],
1769 		       ops, NULL) == ops) ? 0 : -1;
1770 
1771 	synchronize_net();
1772 
1773 	return ret;
1774 }
1775 EXPORT_SYMBOL(ip6_tnl_encap_del_ops);
1776 
1777 int ip6_tnl_encap_setup(struct ip6_tnl *t,
1778 			struct ip_tunnel_encap *ipencap)
1779 {
1780 	int hlen;
1781 
1782 	memset(&t->encap, 0, sizeof(t->encap));
1783 
1784 	hlen = ip6_encap_hlen(ipencap);
1785 	if (hlen < 0)
1786 		return hlen;
1787 
1788 	t->encap.type = ipencap->type;
1789 	t->encap.sport = ipencap->sport;
1790 	t->encap.dport = ipencap->dport;
1791 	t->encap.flags = ipencap->flags;
1792 
1793 	t->encap_hlen = hlen;
1794 	t->hlen = t->encap_hlen + t->tun_hlen;
1795 
1796 	return 0;
1797 }
1798 EXPORT_SYMBOL_GPL(ip6_tnl_encap_setup);
1799 
1800 static const struct net_device_ops ip6_tnl_netdev_ops = {
1801 	.ndo_init	= ip6_tnl_dev_init,
1802 	.ndo_uninit	= ip6_tnl_dev_uninit,
1803 	.ndo_start_xmit = ip6_tnl_start_xmit,
1804 	.ndo_do_ioctl	= ip6_tnl_ioctl,
1805 	.ndo_change_mtu = ip6_tnl_change_mtu,
1806 	.ndo_get_stats64 = dev_get_tstats64,
1807 	.ndo_get_iflink = ip6_tnl_get_iflink,
1808 };
1809 
1810 #define IPXIPX_FEATURES (NETIF_F_SG |		\
1811 			 NETIF_F_FRAGLIST |	\
1812 			 NETIF_F_HIGHDMA |	\
1813 			 NETIF_F_GSO_SOFTWARE |	\
1814 			 NETIF_F_HW_CSUM)
1815 
1816 /**
1817  * ip6_tnl_dev_setup - setup virtual tunnel device
1818  *   @dev: virtual device associated with tunnel
1819  *
1820  * Description:
1821  *   Initialize function pointers and device parameters
1822  **/
1823 
1824 static void ip6_tnl_dev_setup(struct net_device *dev)
1825 {
1826 	dev->netdev_ops = &ip6_tnl_netdev_ops;
1827 	dev->header_ops = &ip_tunnel_header_ops;
1828 	dev->needs_free_netdev = true;
1829 	dev->priv_destructor = ip6_dev_free;
1830 
1831 	dev->type = ARPHRD_TUNNEL6;
1832 	dev->flags |= IFF_NOARP;
1833 	dev->addr_len = sizeof(struct in6_addr);
1834 	dev->features |= NETIF_F_LLTX;
1835 	netif_keep_dst(dev);
1836 
1837 	dev->features		|= IPXIPX_FEATURES;
1838 	dev->hw_features	|= IPXIPX_FEATURES;
1839 
1840 	/* This perm addr will be used as interface identifier by IPv6 */
1841 	dev->addr_assign_type = NET_ADDR_RANDOM;
1842 	eth_random_addr(dev->perm_addr);
1843 }
1844 
1845 
1846 /**
1847  * ip6_tnl_dev_init_gen - general initializer for all tunnel devices
1848  *   @dev: virtual device associated with tunnel
1849  **/
1850 
1851 static inline int
1852 ip6_tnl_dev_init_gen(struct net_device *dev)
1853 {
1854 	struct ip6_tnl *t = netdev_priv(dev);
1855 	int ret;
1856 	int t_hlen;
1857 
1858 	t->dev = dev;
1859 	t->net = dev_net(dev);
1860 	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1861 	if (!dev->tstats)
1862 		return -ENOMEM;
1863 
1864 	ret = dst_cache_init(&t->dst_cache, GFP_KERNEL);
1865 	if (ret)
1866 		goto free_stats;
1867 
1868 	ret = gro_cells_init(&t->gro_cells, dev);
1869 	if (ret)
1870 		goto destroy_dst;
1871 
1872 	t->tun_hlen = 0;
1873 	t->hlen = t->encap_hlen + t->tun_hlen;
1874 	t_hlen = t->hlen + sizeof(struct ipv6hdr);
1875 
1876 	dev->type = ARPHRD_TUNNEL6;
1877 	dev->hard_header_len = LL_MAX_HEADER + t_hlen;
1878 	dev->mtu = ETH_DATA_LEN - t_hlen;
1879 	if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1880 		dev->mtu -= 8;
1881 	dev->min_mtu = ETH_MIN_MTU;
1882 	dev->max_mtu = IP6_MAX_MTU - dev->hard_header_len;
1883 
1884 	dev_hold(dev);
1885 	return 0;
1886 
1887 destroy_dst:
1888 	dst_cache_destroy(&t->dst_cache);
1889 free_stats:
1890 	free_percpu(dev->tstats);
1891 	dev->tstats = NULL;
1892 
1893 	return ret;
1894 }
1895 
1896 /**
1897  * ip6_tnl_dev_init - initializer for all non fallback tunnel devices
1898  *   @dev: virtual device associated with tunnel
1899  **/
1900 
1901 static int ip6_tnl_dev_init(struct net_device *dev)
1902 {
1903 	struct ip6_tnl *t = netdev_priv(dev);
1904 	int err = ip6_tnl_dev_init_gen(dev);
1905 
1906 	if (err)
1907 		return err;
1908 	ip6_tnl_link_config(t);
1909 	if (t->parms.collect_md)
1910 		netif_keep_dst(dev);
1911 	return 0;
1912 }
1913 
1914 /**
1915  * ip6_fb_tnl_dev_init - initializer for fallback tunnel device
1916  *   @dev: fallback device
1917  *
1918  * Return: 0
1919  **/
1920 
1921 static int __net_init ip6_fb_tnl_dev_init(struct net_device *dev)
1922 {
1923 	struct ip6_tnl *t = netdev_priv(dev);
1924 	struct net *net = dev_net(dev);
1925 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1926 
1927 	t->parms.proto = IPPROTO_IPV6;
1928 
1929 	rcu_assign_pointer(ip6n->tnls_wc[0], t);
1930 	return 0;
1931 }
1932 
1933 static int ip6_tnl_validate(struct nlattr *tb[], struct nlattr *data[],
1934 			    struct netlink_ext_ack *extack)
1935 {
1936 	u8 proto;
1937 
1938 	if (!data || !data[IFLA_IPTUN_PROTO])
1939 		return 0;
1940 
1941 	proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1942 	if (proto != IPPROTO_IPV6 &&
1943 	    proto != IPPROTO_IPIP &&
1944 	    proto != 0)
1945 		return -EINVAL;
1946 
1947 	return 0;
1948 }
1949 
1950 static void ip6_tnl_netlink_parms(struct nlattr *data[],
1951 				  struct __ip6_tnl_parm *parms)
1952 {
1953 	memset(parms, 0, sizeof(*parms));
1954 
1955 	if (!data)
1956 		return;
1957 
1958 	if (data[IFLA_IPTUN_LINK])
1959 		parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
1960 
1961 	if (data[IFLA_IPTUN_LOCAL])
1962 		parms->laddr = nla_get_in6_addr(data[IFLA_IPTUN_LOCAL]);
1963 
1964 	if (data[IFLA_IPTUN_REMOTE])
1965 		parms->raddr = nla_get_in6_addr(data[IFLA_IPTUN_REMOTE]);
1966 
1967 	if (data[IFLA_IPTUN_TTL])
1968 		parms->hop_limit = nla_get_u8(data[IFLA_IPTUN_TTL]);
1969 
1970 	if (data[IFLA_IPTUN_ENCAP_LIMIT])
1971 		parms->encap_limit = nla_get_u8(data[IFLA_IPTUN_ENCAP_LIMIT]);
1972 
1973 	if (data[IFLA_IPTUN_FLOWINFO])
1974 		parms->flowinfo = nla_get_be32(data[IFLA_IPTUN_FLOWINFO]);
1975 
1976 	if (data[IFLA_IPTUN_FLAGS])
1977 		parms->flags = nla_get_u32(data[IFLA_IPTUN_FLAGS]);
1978 
1979 	if (data[IFLA_IPTUN_PROTO])
1980 		parms->proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1981 
1982 	if (data[IFLA_IPTUN_COLLECT_METADATA])
1983 		parms->collect_md = true;
1984 
1985 	if (data[IFLA_IPTUN_FWMARK])
1986 		parms->fwmark = nla_get_u32(data[IFLA_IPTUN_FWMARK]);
1987 }
1988 
1989 static bool ip6_tnl_netlink_encap_parms(struct nlattr *data[],
1990 					struct ip_tunnel_encap *ipencap)
1991 {
1992 	bool ret = false;
1993 
1994 	memset(ipencap, 0, sizeof(*ipencap));
1995 
1996 	if (!data)
1997 		return ret;
1998 
1999 	if (data[IFLA_IPTUN_ENCAP_TYPE]) {
2000 		ret = true;
2001 		ipencap->type = nla_get_u16(data[IFLA_IPTUN_ENCAP_TYPE]);
2002 	}
2003 
2004 	if (data[IFLA_IPTUN_ENCAP_FLAGS]) {
2005 		ret = true;
2006 		ipencap->flags = nla_get_u16(data[IFLA_IPTUN_ENCAP_FLAGS]);
2007 	}
2008 
2009 	if (data[IFLA_IPTUN_ENCAP_SPORT]) {
2010 		ret = true;
2011 		ipencap->sport = nla_get_be16(data[IFLA_IPTUN_ENCAP_SPORT]);
2012 	}
2013 
2014 	if (data[IFLA_IPTUN_ENCAP_DPORT]) {
2015 		ret = true;
2016 		ipencap->dport = nla_get_be16(data[IFLA_IPTUN_ENCAP_DPORT]);
2017 	}
2018 
2019 	return ret;
2020 }
2021 
2022 static int ip6_tnl_newlink(struct net *src_net, struct net_device *dev,
2023 			   struct nlattr *tb[], struct nlattr *data[],
2024 			   struct netlink_ext_ack *extack)
2025 {
2026 	struct net *net = dev_net(dev);
2027 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2028 	struct ip_tunnel_encap ipencap;
2029 	struct ip6_tnl *nt, *t;
2030 	int err;
2031 
2032 	nt = netdev_priv(dev);
2033 
2034 	if (ip6_tnl_netlink_encap_parms(data, &ipencap)) {
2035 		err = ip6_tnl_encap_setup(nt, &ipencap);
2036 		if (err < 0)
2037 			return err;
2038 	}
2039 
2040 	ip6_tnl_netlink_parms(data, &nt->parms);
2041 
2042 	if (nt->parms.collect_md) {
2043 		if (rtnl_dereference(ip6n->collect_md_tun))
2044 			return -EEXIST;
2045 	} else {
2046 		t = ip6_tnl_locate(net, &nt->parms, 0);
2047 		if (!IS_ERR(t))
2048 			return -EEXIST;
2049 	}
2050 
2051 	err = ip6_tnl_create2(dev);
2052 	if (!err && tb[IFLA_MTU])
2053 		ip6_tnl_change_mtu(dev, nla_get_u32(tb[IFLA_MTU]));
2054 
2055 	return err;
2056 }
2057 
2058 static int ip6_tnl_changelink(struct net_device *dev, struct nlattr *tb[],
2059 			      struct nlattr *data[],
2060 			      struct netlink_ext_ack *extack)
2061 {
2062 	struct ip6_tnl *t = netdev_priv(dev);
2063 	struct __ip6_tnl_parm p;
2064 	struct net *net = t->net;
2065 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2066 	struct ip_tunnel_encap ipencap;
2067 
2068 	if (dev == ip6n->fb_tnl_dev)
2069 		return -EINVAL;
2070 
2071 	if (ip6_tnl_netlink_encap_parms(data, &ipencap)) {
2072 		int err = ip6_tnl_encap_setup(t, &ipencap);
2073 
2074 		if (err < 0)
2075 			return err;
2076 	}
2077 	ip6_tnl_netlink_parms(data, &p);
2078 	if (p.collect_md)
2079 		return -EINVAL;
2080 
2081 	t = ip6_tnl_locate(net, &p, 0);
2082 	if (!IS_ERR(t)) {
2083 		if (t->dev != dev)
2084 			return -EEXIST;
2085 	} else
2086 		t = netdev_priv(dev);
2087 
2088 	return ip6_tnl_update(t, &p);
2089 }
2090 
2091 static void ip6_tnl_dellink(struct net_device *dev, struct list_head *head)
2092 {
2093 	struct net *net = dev_net(dev);
2094 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2095 
2096 	if (dev != ip6n->fb_tnl_dev)
2097 		unregister_netdevice_queue(dev, head);
2098 }
2099 
2100 static size_t ip6_tnl_get_size(const struct net_device *dev)
2101 {
2102 	return
2103 		/* IFLA_IPTUN_LINK */
2104 		nla_total_size(4) +
2105 		/* IFLA_IPTUN_LOCAL */
2106 		nla_total_size(sizeof(struct in6_addr)) +
2107 		/* IFLA_IPTUN_REMOTE */
2108 		nla_total_size(sizeof(struct in6_addr)) +
2109 		/* IFLA_IPTUN_TTL */
2110 		nla_total_size(1) +
2111 		/* IFLA_IPTUN_ENCAP_LIMIT */
2112 		nla_total_size(1) +
2113 		/* IFLA_IPTUN_FLOWINFO */
2114 		nla_total_size(4) +
2115 		/* IFLA_IPTUN_FLAGS */
2116 		nla_total_size(4) +
2117 		/* IFLA_IPTUN_PROTO */
2118 		nla_total_size(1) +
2119 		/* IFLA_IPTUN_ENCAP_TYPE */
2120 		nla_total_size(2) +
2121 		/* IFLA_IPTUN_ENCAP_FLAGS */
2122 		nla_total_size(2) +
2123 		/* IFLA_IPTUN_ENCAP_SPORT */
2124 		nla_total_size(2) +
2125 		/* IFLA_IPTUN_ENCAP_DPORT */
2126 		nla_total_size(2) +
2127 		/* IFLA_IPTUN_COLLECT_METADATA */
2128 		nla_total_size(0) +
2129 		/* IFLA_IPTUN_FWMARK */
2130 		nla_total_size(4) +
2131 		0;
2132 }
2133 
2134 static int ip6_tnl_fill_info(struct sk_buff *skb, const struct net_device *dev)
2135 {
2136 	struct ip6_tnl *tunnel = netdev_priv(dev);
2137 	struct __ip6_tnl_parm *parm = &tunnel->parms;
2138 
2139 	if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
2140 	    nla_put_in6_addr(skb, IFLA_IPTUN_LOCAL, &parm->laddr) ||
2141 	    nla_put_in6_addr(skb, IFLA_IPTUN_REMOTE, &parm->raddr) ||
2142 	    nla_put_u8(skb, IFLA_IPTUN_TTL, parm->hop_limit) ||
2143 	    nla_put_u8(skb, IFLA_IPTUN_ENCAP_LIMIT, parm->encap_limit) ||
2144 	    nla_put_be32(skb, IFLA_IPTUN_FLOWINFO, parm->flowinfo) ||
2145 	    nla_put_u32(skb, IFLA_IPTUN_FLAGS, parm->flags) ||
2146 	    nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->proto) ||
2147 	    nla_put_u32(skb, IFLA_IPTUN_FWMARK, parm->fwmark))
2148 		goto nla_put_failure;
2149 
2150 	if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE, tunnel->encap.type) ||
2151 	    nla_put_be16(skb, IFLA_IPTUN_ENCAP_SPORT, tunnel->encap.sport) ||
2152 	    nla_put_be16(skb, IFLA_IPTUN_ENCAP_DPORT, tunnel->encap.dport) ||
2153 	    nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS, tunnel->encap.flags))
2154 		goto nla_put_failure;
2155 
2156 	if (parm->collect_md)
2157 		if (nla_put_flag(skb, IFLA_IPTUN_COLLECT_METADATA))
2158 			goto nla_put_failure;
2159 
2160 	return 0;
2161 
2162 nla_put_failure:
2163 	return -EMSGSIZE;
2164 }
2165 
2166 struct net *ip6_tnl_get_link_net(const struct net_device *dev)
2167 {
2168 	struct ip6_tnl *tunnel = netdev_priv(dev);
2169 
2170 	return tunnel->net;
2171 }
2172 EXPORT_SYMBOL(ip6_tnl_get_link_net);
2173 
2174 static const struct nla_policy ip6_tnl_policy[IFLA_IPTUN_MAX + 1] = {
2175 	[IFLA_IPTUN_LINK]		= { .type = NLA_U32 },
2176 	[IFLA_IPTUN_LOCAL]		= { .len = sizeof(struct in6_addr) },
2177 	[IFLA_IPTUN_REMOTE]		= { .len = sizeof(struct in6_addr) },
2178 	[IFLA_IPTUN_TTL]		= { .type = NLA_U8 },
2179 	[IFLA_IPTUN_ENCAP_LIMIT]	= { .type = NLA_U8 },
2180 	[IFLA_IPTUN_FLOWINFO]		= { .type = NLA_U32 },
2181 	[IFLA_IPTUN_FLAGS]		= { .type = NLA_U32 },
2182 	[IFLA_IPTUN_PROTO]		= { .type = NLA_U8 },
2183 	[IFLA_IPTUN_ENCAP_TYPE]		= { .type = NLA_U16 },
2184 	[IFLA_IPTUN_ENCAP_FLAGS]	= { .type = NLA_U16 },
2185 	[IFLA_IPTUN_ENCAP_SPORT]	= { .type = NLA_U16 },
2186 	[IFLA_IPTUN_ENCAP_DPORT]	= { .type = NLA_U16 },
2187 	[IFLA_IPTUN_COLLECT_METADATA]	= { .type = NLA_FLAG },
2188 	[IFLA_IPTUN_FWMARK]		= { .type = NLA_U32 },
2189 };
2190 
2191 static struct rtnl_link_ops ip6_link_ops __read_mostly = {
2192 	.kind		= "ip6tnl",
2193 	.maxtype	= IFLA_IPTUN_MAX,
2194 	.policy		= ip6_tnl_policy,
2195 	.priv_size	= sizeof(struct ip6_tnl),
2196 	.setup		= ip6_tnl_dev_setup,
2197 	.validate	= ip6_tnl_validate,
2198 	.newlink	= ip6_tnl_newlink,
2199 	.changelink	= ip6_tnl_changelink,
2200 	.dellink	= ip6_tnl_dellink,
2201 	.get_size	= ip6_tnl_get_size,
2202 	.fill_info	= ip6_tnl_fill_info,
2203 	.get_link_net	= ip6_tnl_get_link_net,
2204 };
2205 
2206 static struct xfrm6_tunnel ip4ip6_handler __read_mostly = {
2207 	.handler	= ip4ip6_rcv,
2208 	.err_handler	= ip4ip6_err,
2209 	.priority	=	1,
2210 };
2211 
2212 static struct xfrm6_tunnel ip6ip6_handler __read_mostly = {
2213 	.handler	= ip6ip6_rcv,
2214 	.err_handler	= ip6ip6_err,
2215 	.priority	=	1,
2216 };
2217 
2218 static struct xfrm6_tunnel mplsip6_handler __read_mostly = {
2219 	.handler	= mplsip6_rcv,
2220 	.err_handler	= mplsip6_err,
2221 	.priority	=	1,
2222 };
2223 
2224 static void __net_exit ip6_tnl_destroy_tunnels(struct net *net, struct list_head *list)
2225 {
2226 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2227 	struct net_device *dev, *aux;
2228 	int h;
2229 	struct ip6_tnl *t;
2230 
2231 	for_each_netdev_safe(net, dev, aux)
2232 		if (dev->rtnl_link_ops == &ip6_link_ops)
2233 			unregister_netdevice_queue(dev, list);
2234 
2235 	for (h = 0; h < IP6_TUNNEL_HASH_SIZE; h++) {
2236 		t = rtnl_dereference(ip6n->tnls_r_l[h]);
2237 		while (t) {
2238 			/* If dev is in the same netns, it has already
2239 			 * been added to the list by the previous loop.
2240 			 */
2241 			if (!net_eq(dev_net(t->dev), net))
2242 				unregister_netdevice_queue(t->dev, list);
2243 			t = rtnl_dereference(t->next);
2244 		}
2245 	}
2246 
2247 	t = rtnl_dereference(ip6n->tnls_wc[0]);
2248 	while (t) {
2249 		/* If dev is in the same netns, it has already
2250 		 * been added to the list by the previous loop.
2251 		 */
2252 		if (!net_eq(dev_net(t->dev), net))
2253 			unregister_netdevice_queue(t->dev, list);
2254 		t = rtnl_dereference(t->next);
2255 	}
2256 }
2257 
2258 static int __net_init ip6_tnl_init_net(struct net *net)
2259 {
2260 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2261 	struct ip6_tnl *t = NULL;
2262 	int err;
2263 
2264 	ip6n->tnls[0] = ip6n->tnls_wc;
2265 	ip6n->tnls[1] = ip6n->tnls_r_l;
2266 
2267 	if (!net_has_fallback_tunnels(net))
2268 		return 0;
2269 	err = -ENOMEM;
2270 	ip6n->fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6tnl0",
2271 					NET_NAME_UNKNOWN, ip6_tnl_dev_setup);
2272 
2273 	if (!ip6n->fb_tnl_dev)
2274 		goto err_alloc_dev;
2275 	dev_net_set(ip6n->fb_tnl_dev, net);
2276 	ip6n->fb_tnl_dev->rtnl_link_ops = &ip6_link_ops;
2277 	/* FB netdevice is special: we have one, and only one per netns.
2278 	 * Allowing to move it to another netns is clearly unsafe.
2279 	 */
2280 	ip6n->fb_tnl_dev->features |= NETIF_F_NETNS_LOCAL;
2281 
2282 	err = ip6_fb_tnl_dev_init(ip6n->fb_tnl_dev);
2283 	if (err < 0)
2284 		goto err_register;
2285 
2286 	err = register_netdev(ip6n->fb_tnl_dev);
2287 	if (err < 0)
2288 		goto err_register;
2289 
2290 	t = netdev_priv(ip6n->fb_tnl_dev);
2291 
2292 	strcpy(t->parms.name, ip6n->fb_tnl_dev->name);
2293 	return 0;
2294 
2295 err_register:
2296 	free_netdev(ip6n->fb_tnl_dev);
2297 err_alloc_dev:
2298 	return err;
2299 }
2300 
2301 static void __net_exit ip6_tnl_exit_batch_net(struct list_head *net_list)
2302 {
2303 	struct net *net;
2304 	LIST_HEAD(list);
2305 
2306 	rtnl_lock();
2307 	list_for_each_entry(net, net_list, exit_list)
2308 		ip6_tnl_destroy_tunnels(net, &list);
2309 	unregister_netdevice_many(&list);
2310 	rtnl_unlock();
2311 }
2312 
2313 static struct pernet_operations ip6_tnl_net_ops = {
2314 	.init = ip6_tnl_init_net,
2315 	.exit_batch = ip6_tnl_exit_batch_net,
2316 	.id   = &ip6_tnl_net_id,
2317 	.size = sizeof(struct ip6_tnl_net),
2318 };
2319 
2320 /**
2321  * ip6_tunnel_init - register protocol and reserve needed resources
2322  *
2323  * Return: 0 on success
2324  **/
2325 
2326 static int __init ip6_tunnel_init(void)
2327 {
2328 	int  err;
2329 
2330 	if (!ipv6_mod_enabled())
2331 		return -EOPNOTSUPP;
2332 
2333 	err = register_pernet_device(&ip6_tnl_net_ops);
2334 	if (err < 0)
2335 		goto out_pernet;
2336 
2337 	err = xfrm6_tunnel_register(&ip4ip6_handler, AF_INET);
2338 	if (err < 0) {
2339 		pr_err("%s: can't register ip4ip6\n", __func__);
2340 		goto out_ip4ip6;
2341 	}
2342 
2343 	err = xfrm6_tunnel_register(&ip6ip6_handler, AF_INET6);
2344 	if (err < 0) {
2345 		pr_err("%s: can't register ip6ip6\n", __func__);
2346 		goto out_ip6ip6;
2347 	}
2348 
2349 	if (ip6_tnl_mpls_supported()) {
2350 		err = xfrm6_tunnel_register(&mplsip6_handler, AF_MPLS);
2351 		if (err < 0) {
2352 			pr_err("%s: can't register mplsip6\n", __func__);
2353 			goto out_mplsip6;
2354 		}
2355 	}
2356 
2357 	err = rtnl_link_register(&ip6_link_ops);
2358 	if (err < 0)
2359 		goto rtnl_link_failed;
2360 
2361 	return 0;
2362 
2363 rtnl_link_failed:
2364 	if (ip6_tnl_mpls_supported())
2365 		xfrm6_tunnel_deregister(&mplsip6_handler, AF_MPLS);
2366 out_mplsip6:
2367 	xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6);
2368 out_ip6ip6:
2369 	xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET);
2370 out_ip4ip6:
2371 	unregister_pernet_device(&ip6_tnl_net_ops);
2372 out_pernet:
2373 	return err;
2374 }
2375 
2376 /**
2377  * ip6_tunnel_cleanup - free resources and unregister protocol
2378  **/
2379 
2380 static void __exit ip6_tunnel_cleanup(void)
2381 {
2382 	rtnl_link_unregister(&ip6_link_ops);
2383 	if (xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET))
2384 		pr_info("%s: can't deregister ip4ip6\n", __func__);
2385 
2386 	if (xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6))
2387 		pr_info("%s: can't deregister ip6ip6\n", __func__);
2388 
2389 	if (ip6_tnl_mpls_supported() &&
2390 	    xfrm6_tunnel_deregister(&mplsip6_handler, AF_MPLS))
2391 		pr_info("%s: can't deregister mplsip6\n", __func__);
2392 	unregister_pernet_device(&ip6_tnl_net_ops);
2393 }
2394 
2395 module_init(ip6_tunnel_init);
2396 module_exit(ip6_tunnel_cleanup);
2397