xref: /linux/net/ipv6/ip6_tunnel.c (revision 1f8d99de1d1b4b3764203ae02db57041475dab84)
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_track(dev, &t->dev_tracker);
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 		skb_reset_mac_header(skb);
841 	}
842 
843 	skb_reset_network_header(skb);
844 	memset(skb->cb, 0, sizeof(struct inet6_skb_parm));
845 
846 	__skb_tunnel_rx(skb, tunnel->dev, tunnel->net);
847 
848 	err = dscp_ecn_decapsulate(tunnel, ipv6h, skb);
849 	if (unlikely(err)) {
850 		if (log_ecn_err)
851 			net_info_ratelimited("non-ECT from %pI6 with DS=%#x\n",
852 					     &ipv6h->saddr,
853 					     ipv6_get_dsfield(ipv6h));
854 		if (err > 1) {
855 			++tunnel->dev->stats.rx_frame_errors;
856 			++tunnel->dev->stats.rx_errors;
857 			goto drop;
858 		}
859 	}
860 
861 	tstats = this_cpu_ptr(tunnel->dev->tstats);
862 	u64_stats_update_begin(&tstats->syncp);
863 	tstats->rx_packets++;
864 	tstats->rx_bytes += skb->len;
865 	u64_stats_update_end(&tstats->syncp);
866 
867 	skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(tunnel->dev)));
868 
869 	if (tun_dst)
870 		skb_dst_set(skb, (struct dst_entry *)tun_dst);
871 
872 	gro_cells_receive(&tunnel->gro_cells, skb);
873 	return 0;
874 
875 drop:
876 	if (tun_dst)
877 		dst_release((struct dst_entry *)tun_dst);
878 	kfree_skb(skb);
879 	return 0;
880 }
881 
882 int ip6_tnl_rcv(struct ip6_tnl *t, struct sk_buff *skb,
883 		const struct tnl_ptk_info *tpi,
884 		struct metadata_dst *tun_dst,
885 		bool log_ecn_err)
886 {
887 	int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
888 				    const struct ipv6hdr *ipv6h,
889 				    struct sk_buff *skb);
890 
891 	dscp_ecn_decapsulate = ip6ip6_dscp_ecn_decapsulate;
892 	if (tpi->proto == htons(ETH_P_IP))
893 		dscp_ecn_decapsulate = ip4ip6_dscp_ecn_decapsulate;
894 
895 	return __ip6_tnl_rcv(t, skb, tpi, tun_dst, dscp_ecn_decapsulate,
896 			     log_ecn_err);
897 }
898 EXPORT_SYMBOL(ip6_tnl_rcv);
899 
900 static const struct tnl_ptk_info tpi_v6 = {
901 	/* no tunnel info required for ipxip6. */
902 	.proto = htons(ETH_P_IPV6),
903 };
904 
905 static const struct tnl_ptk_info tpi_v4 = {
906 	/* no tunnel info required for ipxip6. */
907 	.proto = htons(ETH_P_IP),
908 };
909 
910 static const struct tnl_ptk_info tpi_mpls = {
911 	/* no tunnel info required for mplsip6. */
912 	.proto = htons(ETH_P_MPLS_UC),
913 };
914 
915 static int ipxip6_rcv(struct sk_buff *skb, u8 ipproto,
916 		      const struct tnl_ptk_info *tpi,
917 		      int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
918 						  const struct ipv6hdr *ipv6h,
919 						  struct sk_buff *skb))
920 {
921 	struct ip6_tnl *t;
922 	const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
923 	struct metadata_dst *tun_dst = NULL;
924 	int ret = -1;
925 
926 	rcu_read_lock();
927 	t = ip6_tnl_lookup(dev_net(skb->dev), skb->dev->ifindex, &ipv6h->saddr, &ipv6h->daddr);
928 
929 	if (t) {
930 		u8 tproto = READ_ONCE(t->parms.proto);
931 
932 		if (tproto != ipproto && tproto != 0)
933 			goto drop;
934 		if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
935 			goto drop;
936 		ipv6h = ipv6_hdr(skb);
937 		if (!ip6_tnl_rcv_ctl(t, &ipv6h->daddr, &ipv6h->saddr))
938 			goto drop;
939 		if (iptunnel_pull_header(skb, 0, tpi->proto, false))
940 			goto drop;
941 		if (t->parms.collect_md) {
942 			tun_dst = ipv6_tun_rx_dst(skb, 0, 0, 0);
943 			if (!tun_dst)
944 				goto drop;
945 		}
946 		ret = __ip6_tnl_rcv(t, skb, tpi, tun_dst, dscp_ecn_decapsulate,
947 				    log_ecn_error);
948 	}
949 
950 	rcu_read_unlock();
951 
952 	return ret;
953 
954 drop:
955 	rcu_read_unlock();
956 	kfree_skb(skb);
957 	return 0;
958 }
959 
960 static int ip4ip6_rcv(struct sk_buff *skb)
961 {
962 	return ipxip6_rcv(skb, IPPROTO_IPIP, &tpi_v4,
963 			  ip4ip6_dscp_ecn_decapsulate);
964 }
965 
966 static int ip6ip6_rcv(struct sk_buff *skb)
967 {
968 	return ipxip6_rcv(skb, IPPROTO_IPV6, &tpi_v6,
969 			  ip6ip6_dscp_ecn_decapsulate);
970 }
971 
972 static int mplsip6_rcv(struct sk_buff *skb)
973 {
974 	return ipxip6_rcv(skb, IPPROTO_MPLS, &tpi_mpls,
975 			  mplsip6_dscp_ecn_decapsulate);
976 }
977 
978 struct ipv6_tel_txoption {
979 	struct ipv6_txoptions ops;
980 	__u8 dst_opt[8];
981 };
982 
983 static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit)
984 {
985 	memset(opt, 0, sizeof(struct ipv6_tel_txoption));
986 
987 	opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT;
988 	opt->dst_opt[3] = 1;
989 	opt->dst_opt[4] = encap_limit;
990 	opt->dst_opt[5] = IPV6_TLV_PADN;
991 	opt->dst_opt[6] = 1;
992 
993 	opt->ops.dst1opt = (struct ipv6_opt_hdr *) opt->dst_opt;
994 	opt->ops.opt_nflen = 8;
995 }
996 
997 /**
998  * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
999  *   @t: the outgoing tunnel device
1000  *   @hdr: IPv6 header from the incoming packet
1001  *
1002  * Description:
1003  *   Avoid trivial tunneling loop by checking that tunnel exit-point
1004  *   doesn't match source of incoming packet.
1005  *
1006  * Return:
1007  *   1 if conflict,
1008  *   0 else
1009  **/
1010 
1011 static inline bool
1012 ip6_tnl_addr_conflict(const struct ip6_tnl *t, const struct ipv6hdr *hdr)
1013 {
1014 	return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
1015 }
1016 
1017 int ip6_tnl_xmit_ctl(struct ip6_tnl *t,
1018 		     const struct in6_addr *laddr,
1019 		     const struct in6_addr *raddr)
1020 {
1021 	struct __ip6_tnl_parm *p = &t->parms;
1022 	int ret = 0;
1023 	struct net *net = t->net;
1024 
1025 	if (t->parms.collect_md)
1026 		return 1;
1027 
1028 	if ((p->flags & IP6_TNL_F_CAP_XMIT) ||
1029 	    ((p->flags & IP6_TNL_F_CAP_PER_PACKET) &&
1030 	     (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_XMIT))) {
1031 		struct net_device *ldev = NULL;
1032 
1033 		rcu_read_lock();
1034 		if (p->link)
1035 			ldev = dev_get_by_index_rcu(net, p->link);
1036 
1037 		if (unlikely(!ipv6_chk_addr_and_flags(net, laddr, ldev, false,
1038 						      0, IFA_F_TENTATIVE)))
1039 			pr_warn_ratelimited("%s xmit: Local address not yet configured!\n",
1040 					    p->name);
1041 		else if (!(p->flags & IP6_TNL_F_ALLOW_LOCAL_REMOTE) &&
1042 			 !ipv6_addr_is_multicast(raddr) &&
1043 			 unlikely(ipv6_chk_addr_and_flags(net, raddr, ldev,
1044 							  true, 0, IFA_F_TENTATIVE)))
1045 			pr_warn_ratelimited("%s xmit: Routing loop! Remote address found on this node!\n",
1046 					    p->name);
1047 		else
1048 			ret = 1;
1049 		rcu_read_unlock();
1050 	}
1051 	return ret;
1052 }
1053 EXPORT_SYMBOL_GPL(ip6_tnl_xmit_ctl);
1054 
1055 /**
1056  * ip6_tnl_xmit - encapsulate packet and send
1057  *   @skb: the outgoing socket buffer
1058  *   @dev: the outgoing tunnel device
1059  *   @dsfield: dscp code for outer header
1060  *   @fl6: flow of tunneled packet
1061  *   @encap_limit: encapsulation limit
1062  *   @pmtu: Path MTU is stored if packet is too big
1063  *   @proto: next header value
1064  *
1065  * Description:
1066  *   Build new header and do some sanity checks on the packet before sending
1067  *   it.
1068  *
1069  * Return:
1070  *   0 on success
1071  *   -1 fail
1072  *   %-EMSGSIZE message too big. return mtu in this case.
1073  **/
1074 
1075 int ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev, __u8 dsfield,
1076 		 struct flowi6 *fl6, int encap_limit, __u32 *pmtu,
1077 		 __u8 proto)
1078 {
1079 	struct ip6_tnl *t = netdev_priv(dev);
1080 	struct net *net = t->net;
1081 	struct net_device_stats *stats = &t->dev->stats;
1082 	struct ipv6hdr *ipv6h;
1083 	struct ipv6_tel_txoption opt;
1084 	struct dst_entry *dst = NULL, *ndst = NULL;
1085 	struct net_device *tdev;
1086 	int mtu;
1087 	unsigned int eth_hlen = t->dev->type == ARPHRD_ETHER ? ETH_HLEN : 0;
1088 	unsigned int psh_hlen = sizeof(struct ipv6hdr) + t->encap_hlen;
1089 	unsigned int max_headroom = psh_hlen;
1090 	bool use_cache = false;
1091 	u8 hop_limit;
1092 	int err = -1;
1093 
1094 	if (t->parms.collect_md) {
1095 		hop_limit = skb_tunnel_info(skb)->key.ttl;
1096 		goto route_lookup;
1097 	} else {
1098 		hop_limit = t->parms.hop_limit;
1099 	}
1100 
1101 	/* NBMA tunnel */
1102 	if (ipv6_addr_any(&t->parms.raddr)) {
1103 		if (skb->protocol == htons(ETH_P_IPV6)) {
1104 			struct in6_addr *addr6;
1105 			struct neighbour *neigh;
1106 			int addr_type;
1107 
1108 			if (!skb_dst(skb))
1109 				goto tx_err_link_failure;
1110 
1111 			neigh = dst_neigh_lookup(skb_dst(skb),
1112 						 &ipv6_hdr(skb)->daddr);
1113 			if (!neigh)
1114 				goto tx_err_link_failure;
1115 
1116 			addr6 = (struct in6_addr *)&neigh->primary_key;
1117 			addr_type = ipv6_addr_type(addr6);
1118 
1119 			if (addr_type == IPV6_ADDR_ANY)
1120 				addr6 = &ipv6_hdr(skb)->daddr;
1121 
1122 			memcpy(&fl6->daddr, addr6, sizeof(fl6->daddr));
1123 			neigh_release(neigh);
1124 		} else if (skb->protocol == htons(ETH_P_IP)) {
1125 			struct rtable *rt = skb_rtable(skb);
1126 
1127 			if (rt->rt_gw_family == AF_INET6)
1128 				memcpy(&fl6->daddr, &rt->rt_gw6, sizeof(fl6->daddr));
1129 		}
1130 	} else if (t->parms.proto != 0 && !(t->parms.flags &
1131 					    (IP6_TNL_F_USE_ORIG_TCLASS |
1132 					     IP6_TNL_F_USE_ORIG_FWMARK))) {
1133 		/* enable the cache only if neither the outer protocol nor the
1134 		 * routing decision depends on the current inner header value
1135 		 */
1136 		use_cache = true;
1137 	}
1138 
1139 	if (use_cache)
1140 		dst = dst_cache_get(&t->dst_cache);
1141 
1142 	if (!ip6_tnl_xmit_ctl(t, &fl6->saddr, &fl6->daddr))
1143 		goto tx_err_link_failure;
1144 
1145 	if (!dst) {
1146 route_lookup:
1147 		/* add dsfield to flowlabel for route lookup */
1148 		fl6->flowlabel = ip6_make_flowinfo(dsfield, fl6->flowlabel);
1149 
1150 		dst = ip6_route_output(net, NULL, fl6);
1151 
1152 		if (dst->error)
1153 			goto tx_err_link_failure;
1154 		dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), NULL, 0);
1155 		if (IS_ERR(dst)) {
1156 			err = PTR_ERR(dst);
1157 			dst = NULL;
1158 			goto tx_err_link_failure;
1159 		}
1160 		if (t->parms.collect_md && ipv6_addr_any(&fl6->saddr) &&
1161 		    ipv6_dev_get_saddr(net, ip6_dst_idev(dst)->dev,
1162 				       &fl6->daddr, 0, &fl6->saddr))
1163 			goto tx_err_link_failure;
1164 		ndst = dst;
1165 	}
1166 
1167 	tdev = dst->dev;
1168 
1169 	if (tdev == dev) {
1170 		stats->collisions++;
1171 		net_warn_ratelimited("%s: Local routing loop detected!\n",
1172 				     t->parms.name);
1173 		goto tx_err_dst_release;
1174 	}
1175 	mtu = dst_mtu(dst) - eth_hlen - psh_hlen - t->tun_hlen;
1176 	if (encap_limit >= 0) {
1177 		max_headroom += 8;
1178 		mtu -= 8;
1179 	}
1180 	mtu = max(mtu, skb->protocol == htons(ETH_P_IPV6) ?
1181 		       IPV6_MIN_MTU : IPV4_MIN_MTU);
1182 
1183 	skb_dst_update_pmtu_no_confirm(skb, mtu);
1184 	if (skb->len - t->tun_hlen - eth_hlen > mtu && !skb_is_gso(skb)) {
1185 		*pmtu = mtu;
1186 		err = -EMSGSIZE;
1187 		goto tx_err_dst_release;
1188 	}
1189 
1190 	if (t->err_count > 0) {
1191 		if (time_before(jiffies,
1192 				t->err_time + IP6TUNNEL_ERR_TIMEO)) {
1193 			t->err_count--;
1194 
1195 			dst_link_failure(skb);
1196 		} else {
1197 			t->err_count = 0;
1198 		}
1199 	}
1200 
1201 	skb_scrub_packet(skb, !net_eq(t->net, dev_net(dev)));
1202 
1203 	/*
1204 	 * Okay, now see if we can stuff it in the buffer as-is.
1205 	 */
1206 	max_headroom += LL_RESERVED_SPACE(tdev);
1207 
1208 	if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
1209 	    (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
1210 		struct sk_buff *new_skb;
1211 
1212 		new_skb = skb_realloc_headroom(skb, max_headroom);
1213 		if (!new_skb)
1214 			goto tx_err_dst_release;
1215 
1216 		if (skb->sk)
1217 			skb_set_owner_w(new_skb, skb->sk);
1218 		consume_skb(skb);
1219 		skb = new_skb;
1220 	}
1221 
1222 	if (t->parms.collect_md) {
1223 		if (t->encap.type != TUNNEL_ENCAP_NONE)
1224 			goto tx_err_dst_release;
1225 	} else {
1226 		if (use_cache && ndst)
1227 			dst_cache_set_ip6(&t->dst_cache, ndst, &fl6->saddr);
1228 	}
1229 	skb_dst_set(skb, dst);
1230 
1231 	if (hop_limit == 0) {
1232 		if (skb->protocol == htons(ETH_P_IP))
1233 			hop_limit = ip_hdr(skb)->ttl;
1234 		else if (skb->protocol == htons(ETH_P_IPV6))
1235 			hop_limit = ipv6_hdr(skb)->hop_limit;
1236 		else
1237 			hop_limit = ip6_dst_hoplimit(dst);
1238 	}
1239 
1240 	/* Calculate max headroom for all the headers and adjust
1241 	 * needed_headroom if necessary.
1242 	 */
1243 	max_headroom = LL_RESERVED_SPACE(dst->dev) + sizeof(struct ipv6hdr)
1244 			+ dst->header_len + t->hlen;
1245 	if (max_headroom > dev->needed_headroom)
1246 		dev->needed_headroom = max_headroom;
1247 
1248 	err = ip6_tnl_encap(skb, t, &proto, fl6);
1249 	if (err)
1250 		return err;
1251 
1252 	if (encap_limit >= 0) {
1253 		init_tel_txopt(&opt, encap_limit);
1254 		ipv6_push_frag_opts(skb, &opt.ops, &proto);
1255 	}
1256 
1257 	skb_push(skb, sizeof(struct ipv6hdr));
1258 	skb_reset_network_header(skb);
1259 	ipv6h = ipv6_hdr(skb);
1260 	ip6_flow_hdr(ipv6h, dsfield,
1261 		     ip6_make_flowlabel(net, skb, fl6->flowlabel, true, fl6));
1262 	ipv6h->hop_limit = hop_limit;
1263 	ipv6h->nexthdr = proto;
1264 	ipv6h->saddr = fl6->saddr;
1265 	ipv6h->daddr = fl6->daddr;
1266 	ip6tunnel_xmit(NULL, skb, dev);
1267 	return 0;
1268 tx_err_link_failure:
1269 	stats->tx_carrier_errors++;
1270 	dst_link_failure(skb);
1271 tx_err_dst_release:
1272 	dst_release(dst);
1273 	return err;
1274 }
1275 EXPORT_SYMBOL(ip6_tnl_xmit);
1276 
1277 static inline int
1278 ipxip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev,
1279 		u8 protocol)
1280 {
1281 	struct ip6_tnl *t = netdev_priv(dev);
1282 	struct ipv6hdr *ipv6h;
1283 	const struct iphdr  *iph;
1284 	int encap_limit = -1;
1285 	__u16 offset;
1286 	struct flowi6 fl6;
1287 	__u8 dsfield, orig_dsfield;
1288 	__u32 mtu;
1289 	u8 tproto;
1290 	int err;
1291 
1292 	tproto = READ_ONCE(t->parms.proto);
1293 	if (tproto != protocol && tproto != 0)
1294 		return -1;
1295 
1296 	if (t->parms.collect_md) {
1297 		struct ip_tunnel_info *tun_info;
1298 		const struct ip_tunnel_key *key;
1299 
1300 		tun_info = skb_tunnel_info(skb);
1301 		if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
1302 			     ip_tunnel_info_af(tun_info) != AF_INET6))
1303 			return -1;
1304 		key = &tun_info->key;
1305 		memset(&fl6, 0, sizeof(fl6));
1306 		fl6.flowi6_proto = protocol;
1307 		fl6.saddr = key->u.ipv6.src;
1308 		fl6.daddr = key->u.ipv6.dst;
1309 		fl6.flowlabel = key->label;
1310 		dsfield =  key->tos;
1311 		switch (protocol) {
1312 		case IPPROTO_IPIP:
1313 			iph = ip_hdr(skb);
1314 			orig_dsfield = ipv4_get_dsfield(iph);
1315 			break;
1316 		case IPPROTO_IPV6:
1317 			ipv6h = ipv6_hdr(skb);
1318 			orig_dsfield = ipv6_get_dsfield(ipv6h);
1319 			break;
1320 		default:
1321 			orig_dsfield = dsfield;
1322 			break;
1323 		}
1324 	} else {
1325 		if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1326 			encap_limit = t->parms.encap_limit;
1327 		if (protocol == IPPROTO_IPV6) {
1328 			offset = ip6_tnl_parse_tlv_enc_lim(skb,
1329 						skb_network_header(skb));
1330 			/* ip6_tnl_parse_tlv_enc_lim() might have
1331 			 * reallocated skb->head
1332 			 */
1333 			if (offset > 0) {
1334 				struct ipv6_tlv_tnl_enc_lim *tel;
1335 
1336 				tel = (void *)&skb_network_header(skb)[offset];
1337 				if (tel->encap_limit == 0) {
1338 					icmpv6_ndo_send(skb, ICMPV6_PARAMPROB,
1339 							ICMPV6_HDR_FIELD, offset + 2);
1340 					return -1;
1341 				}
1342 				encap_limit = tel->encap_limit - 1;
1343 			}
1344 		}
1345 
1346 		memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
1347 		fl6.flowi6_proto = protocol;
1348 
1349 		if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
1350 			fl6.flowi6_mark = skb->mark;
1351 		else
1352 			fl6.flowi6_mark = t->parms.fwmark;
1353 		switch (protocol) {
1354 		case IPPROTO_IPIP:
1355 			iph = ip_hdr(skb);
1356 			orig_dsfield = ipv4_get_dsfield(iph);
1357 			if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1358 				dsfield = orig_dsfield;
1359 			else
1360 				dsfield = ip6_tclass(t->parms.flowinfo);
1361 			break;
1362 		case IPPROTO_IPV6:
1363 			ipv6h = ipv6_hdr(skb);
1364 			orig_dsfield = ipv6_get_dsfield(ipv6h);
1365 			if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1366 				dsfield = orig_dsfield;
1367 			else
1368 				dsfield = ip6_tclass(t->parms.flowinfo);
1369 			if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
1370 				fl6.flowlabel |= ip6_flowlabel(ipv6h);
1371 			break;
1372 		default:
1373 			orig_dsfield = dsfield = ip6_tclass(t->parms.flowinfo);
1374 			break;
1375 		}
1376 	}
1377 
1378 	fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
1379 	dsfield = INET_ECN_encapsulate(dsfield, orig_dsfield);
1380 
1381 	if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP6))
1382 		return -1;
1383 
1384 	skb_set_inner_ipproto(skb, protocol);
1385 
1386 	err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
1387 			   protocol);
1388 	if (err != 0) {
1389 		/* XXX: send ICMP error even if DF is not set. */
1390 		if (err == -EMSGSIZE)
1391 			switch (protocol) {
1392 			case IPPROTO_IPIP:
1393 				icmp_ndo_send(skb, ICMP_DEST_UNREACH,
1394 					      ICMP_FRAG_NEEDED, htonl(mtu));
1395 				break;
1396 			case IPPROTO_IPV6:
1397 				icmpv6_ndo_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
1398 				break;
1399 			default:
1400 				break;
1401 			}
1402 		return -1;
1403 	}
1404 
1405 	return 0;
1406 }
1407 
1408 static netdev_tx_t
1409 ip6_tnl_start_xmit(struct sk_buff *skb, struct net_device *dev)
1410 {
1411 	struct ip6_tnl *t = netdev_priv(dev);
1412 	struct net_device_stats *stats = &t->dev->stats;
1413 	u8 ipproto;
1414 	int ret;
1415 
1416 	if (!pskb_inet_may_pull(skb))
1417 		goto tx_err;
1418 
1419 	switch (skb->protocol) {
1420 	case htons(ETH_P_IP):
1421 		ipproto = IPPROTO_IPIP;
1422 		break;
1423 	case htons(ETH_P_IPV6):
1424 		if (ip6_tnl_addr_conflict(t, ipv6_hdr(skb)))
1425 			goto tx_err;
1426 		ipproto = IPPROTO_IPV6;
1427 		break;
1428 	case htons(ETH_P_MPLS_UC):
1429 		ipproto = IPPROTO_MPLS;
1430 		break;
1431 	default:
1432 		goto tx_err;
1433 	}
1434 
1435 	ret = ipxip6_tnl_xmit(skb, dev, ipproto);
1436 	if (ret < 0)
1437 		goto tx_err;
1438 
1439 	return NETDEV_TX_OK;
1440 
1441 tx_err:
1442 	stats->tx_errors++;
1443 	stats->tx_dropped++;
1444 	kfree_skb(skb);
1445 	return NETDEV_TX_OK;
1446 }
1447 
1448 static void ip6_tnl_link_config(struct ip6_tnl *t)
1449 {
1450 	struct net_device *dev = t->dev;
1451 	struct net_device *tdev = NULL;
1452 	struct __ip6_tnl_parm *p = &t->parms;
1453 	struct flowi6 *fl6 = &t->fl.u.ip6;
1454 	unsigned int mtu;
1455 	int t_hlen;
1456 
1457 	__dev_addr_set(dev, &p->laddr, sizeof(struct in6_addr));
1458 	memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
1459 
1460 	/* Set up flowi template */
1461 	fl6->saddr = p->laddr;
1462 	fl6->daddr = p->raddr;
1463 	fl6->flowi6_oif = p->link;
1464 	fl6->flowlabel = 0;
1465 
1466 	if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
1467 		fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
1468 	if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
1469 		fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
1470 
1471 	p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
1472 	p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
1473 
1474 	if (p->flags&IP6_TNL_F_CAP_XMIT && p->flags&IP6_TNL_F_CAP_RCV)
1475 		dev->flags |= IFF_POINTOPOINT;
1476 	else
1477 		dev->flags &= ~IFF_POINTOPOINT;
1478 
1479 	t->tun_hlen = 0;
1480 	t->hlen = t->encap_hlen + t->tun_hlen;
1481 	t_hlen = t->hlen + sizeof(struct ipv6hdr);
1482 
1483 	if (p->flags & IP6_TNL_F_CAP_XMIT) {
1484 		int strict = (ipv6_addr_type(&p->raddr) &
1485 			      (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
1486 
1487 		struct rt6_info *rt = rt6_lookup(t->net,
1488 						 &p->raddr, &p->laddr,
1489 						 p->link, NULL, strict);
1490 		if (rt) {
1491 			tdev = rt->dst.dev;
1492 			ip6_rt_put(rt);
1493 		}
1494 
1495 		if (!tdev && p->link)
1496 			tdev = __dev_get_by_index(t->net, p->link);
1497 
1498 		if (tdev) {
1499 			dev->hard_header_len = tdev->hard_header_len + t_hlen;
1500 			mtu = min_t(unsigned int, tdev->mtu, IP6_MAX_MTU);
1501 
1502 			dev->mtu = mtu - t_hlen;
1503 			if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1504 				dev->mtu -= 8;
1505 
1506 			if (dev->mtu < IPV6_MIN_MTU)
1507 				dev->mtu = IPV6_MIN_MTU;
1508 		}
1509 	}
1510 }
1511 
1512 /**
1513  * ip6_tnl_change - update the tunnel parameters
1514  *   @t: tunnel to be changed
1515  *   @p: tunnel configuration parameters
1516  *
1517  * Description:
1518  *   ip6_tnl_change() updates the tunnel parameters
1519  **/
1520 
1521 static int
1522 ip6_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p)
1523 {
1524 	t->parms.laddr = p->laddr;
1525 	t->parms.raddr = p->raddr;
1526 	t->parms.flags = p->flags;
1527 	t->parms.hop_limit = p->hop_limit;
1528 	t->parms.encap_limit = p->encap_limit;
1529 	t->parms.flowinfo = p->flowinfo;
1530 	t->parms.link = p->link;
1531 	t->parms.proto = p->proto;
1532 	t->parms.fwmark = p->fwmark;
1533 	dst_cache_reset(&t->dst_cache);
1534 	ip6_tnl_link_config(t);
1535 	return 0;
1536 }
1537 
1538 static int ip6_tnl_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
1539 {
1540 	struct net *net = t->net;
1541 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1542 	int err;
1543 
1544 	ip6_tnl_unlink(ip6n, t);
1545 	synchronize_net();
1546 	err = ip6_tnl_change(t, p);
1547 	ip6_tnl_link(ip6n, t);
1548 	netdev_state_change(t->dev);
1549 	return err;
1550 }
1551 
1552 static int ip6_tnl0_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
1553 {
1554 	/* for default tnl0 device allow to change only the proto */
1555 	t->parms.proto = p->proto;
1556 	netdev_state_change(t->dev);
1557 	return 0;
1558 }
1559 
1560 static void
1561 ip6_tnl_parm_from_user(struct __ip6_tnl_parm *p, const struct ip6_tnl_parm *u)
1562 {
1563 	p->laddr = u->laddr;
1564 	p->raddr = u->raddr;
1565 	p->flags = u->flags;
1566 	p->hop_limit = u->hop_limit;
1567 	p->encap_limit = u->encap_limit;
1568 	p->flowinfo = u->flowinfo;
1569 	p->link = u->link;
1570 	p->proto = u->proto;
1571 	memcpy(p->name, u->name, sizeof(u->name));
1572 }
1573 
1574 static void
1575 ip6_tnl_parm_to_user(struct ip6_tnl_parm *u, const struct __ip6_tnl_parm *p)
1576 {
1577 	u->laddr = p->laddr;
1578 	u->raddr = p->raddr;
1579 	u->flags = p->flags;
1580 	u->hop_limit = p->hop_limit;
1581 	u->encap_limit = p->encap_limit;
1582 	u->flowinfo = p->flowinfo;
1583 	u->link = p->link;
1584 	u->proto = p->proto;
1585 	memcpy(u->name, p->name, sizeof(u->name));
1586 }
1587 
1588 /**
1589  * ip6_tnl_siocdevprivate - configure ipv6 tunnels from userspace
1590  *   @dev: virtual device associated with tunnel
1591  *   @ifr: unused
1592  *   @data: parameters passed from userspace
1593  *   @cmd: command to be performed
1594  *
1595  * Description:
1596  *   ip6_tnl_ioctl() is used for managing IPv6 tunnels
1597  *   from userspace.
1598  *
1599  *   The possible commands are the following:
1600  *     %SIOCGETTUNNEL: get tunnel parameters for device
1601  *     %SIOCADDTUNNEL: add tunnel matching given tunnel parameters
1602  *     %SIOCCHGTUNNEL: change tunnel parameters to those given
1603  *     %SIOCDELTUNNEL: delete tunnel
1604  *
1605  *   The fallback device "ip6tnl0", created during module
1606  *   initialization, can be used for creating other tunnel devices.
1607  *
1608  * Return:
1609  *   0 on success,
1610  *   %-EFAULT if unable to copy data to or from userspace,
1611  *   %-EPERM if current process hasn't %CAP_NET_ADMIN set
1612  *   %-EINVAL if passed tunnel parameters are invalid,
1613  *   %-EEXIST if changing a tunnel's parameters would cause a conflict
1614  *   %-ENODEV if attempting to change or delete a nonexisting device
1615  **/
1616 
1617 static int
1618 ip6_tnl_siocdevprivate(struct net_device *dev, struct ifreq *ifr,
1619 		       void __user *data, int cmd)
1620 {
1621 	int err = 0;
1622 	struct ip6_tnl_parm p;
1623 	struct __ip6_tnl_parm p1;
1624 	struct ip6_tnl *t = netdev_priv(dev);
1625 	struct net *net = t->net;
1626 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1627 
1628 	memset(&p1, 0, sizeof(p1));
1629 
1630 	switch (cmd) {
1631 	case SIOCGETTUNNEL:
1632 		if (dev == ip6n->fb_tnl_dev) {
1633 			if (copy_from_user(&p, data, sizeof(p))) {
1634 				err = -EFAULT;
1635 				break;
1636 			}
1637 			ip6_tnl_parm_from_user(&p1, &p);
1638 			t = ip6_tnl_locate(net, &p1, 0);
1639 			if (IS_ERR(t))
1640 				t = netdev_priv(dev);
1641 		} else {
1642 			memset(&p, 0, sizeof(p));
1643 		}
1644 		ip6_tnl_parm_to_user(&p, &t->parms);
1645 		if (copy_to_user(data, &p, sizeof(p)))
1646 			err = -EFAULT;
1647 		break;
1648 	case SIOCADDTUNNEL:
1649 	case SIOCCHGTUNNEL:
1650 		err = -EPERM;
1651 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1652 			break;
1653 		err = -EFAULT;
1654 		if (copy_from_user(&p, data, sizeof(p)))
1655 			break;
1656 		err = -EINVAL;
1657 		if (p.proto != IPPROTO_IPV6 && p.proto != IPPROTO_IPIP &&
1658 		    p.proto != 0)
1659 			break;
1660 		ip6_tnl_parm_from_user(&p1, &p);
1661 		t = ip6_tnl_locate(net, &p1, cmd == SIOCADDTUNNEL);
1662 		if (cmd == SIOCCHGTUNNEL) {
1663 			if (!IS_ERR(t)) {
1664 				if (t->dev != dev) {
1665 					err = -EEXIST;
1666 					break;
1667 				}
1668 			} else
1669 				t = netdev_priv(dev);
1670 			if (dev == ip6n->fb_tnl_dev)
1671 				err = ip6_tnl0_update(t, &p1);
1672 			else
1673 				err = ip6_tnl_update(t, &p1);
1674 		}
1675 		if (!IS_ERR(t)) {
1676 			err = 0;
1677 			ip6_tnl_parm_to_user(&p, &t->parms);
1678 			if (copy_to_user(data, &p, sizeof(p)))
1679 				err = -EFAULT;
1680 
1681 		} else {
1682 			err = PTR_ERR(t);
1683 		}
1684 		break;
1685 	case SIOCDELTUNNEL:
1686 		err = -EPERM;
1687 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1688 			break;
1689 
1690 		if (dev == ip6n->fb_tnl_dev) {
1691 			err = -EFAULT;
1692 			if (copy_from_user(&p, data, sizeof(p)))
1693 				break;
1694 			err = -ENOENT;
1695 			ip6_tnl_parm_from_user(&p1, &p);
1696 			t = ip6_tnl_locate(net, &p1, 0);
1697 			if (IS_ERR(t))
1698 				break;
1699 			err = -EPERM;
1700 			if (t->dev == ip6n->fb_tnl_dev)
1701 				break;
1702 			dev = t->dev;
1703 		}
1704 		err = 0;
1705 		unregister_netdevice(dev);
1706 		break;
1707 	default:
1708 		err = -EINVAL;
1709 	}
1710 	return err;
1711 }
1712 
1713 /**
1714  * ip6_tnl_change_mtu - change mtu manually for tunnel device
1715  *   @dev: virtual device associated with tunnel
1716  *   @new_mtu: the new mtu
1717  *
1718  * Return:
1719  *   0 on success,
1720  *   %-EINVAL if mtu too small
1721  **/
1722 
1723 int ip6_tnl_change_mtu(struct net_device *dev, int new_mtu)
1724 {
1725 	struct ip6_tnl *tnl = netdev_priv(dev);
1726 
1727 	if (tnl->parms.proto == IPPROTO_IPV6) {
1728 		if (new_mtu < IPV6_MIN_MTU)
1729 			return -EINVAL;
1730 	} else {
1731 		if (new_mtu < ETH_MIN_MTU)
1732 			return -EINVAL;
1733 	}
1734 	if (tnl->parms.proto == IPPROTO_IPV6 || tnl->parms.proto == 0) {
1735 		if (new_mtu > IP6_MAX_MTU - dev->hard_header_len)
1736 			return -EINVAL;
1737 	} else {
1738 		if (new_mtu > IP_MAX_MTU - dev->hard_header_len)
1739 			return -EINVAL;
1740 	}
1741 	dev->mtu = new_mtu;
1742 	return 0;
1743 }
1744 EXPORT_SYMBOL(ip6_tnl_change_mtu);
1745 
1746 int ip6_tnl_get_iflink(const struct net_device *dev)
1747 {
1748 	struct ip6_tnl *t = netdev_priv(dev);
1749 
1750 	return t->parms.link;
1751 }
1752 EXPORT_SYMBOL(ip6_tnl_get_iflink);
1753 
1754 int ip6_tnl_encap_add_ops(const struct ip6_tnl_encap_ops *ops,
1755 			  unsigned int num)
1756 {
1757 	if (num >= MAX_IPTUN_ENCAP_OPS)
1758 		return -ERANGE;
1759 
1760 	return !cmpxchg((const struct ip6_tnl_encap_ops **)
1761 			&ip6tun_encaps[num],
1762 			NULL, ops) ? 0 : -1;
1763 }
1764 EXPORT_SYMBOL(ip6_tnl_encap_add_ops);
1765 
1766 int ip6_tnl_encap_del_ops(const struct ip6_tnl_encap_ops *ops,
1767 			  unsigned int num)
1768 {
1769 	int ret;
1770 
1771 	if (num >= MAX_IPTUN_ENCAP_OPS)
1772 		return -ERANGE;
1773 
1774 	ret = (cmpxchg((const struct ip6_tnl_encap_ops **)
1775 		       &ip6tun_encaps[num],
1776 		       ops, NULL) == ops) ? 0 : -1;
1777 
1778 	synchronize_net();
1779 
1780 	return ret;
1781 }
1782 EXPORT_SYMBOL(ip6_tnl_encap_del_ops);
1783 
1784 int ip6_tnl_encap_setup(struct ip6_tnl *t,
1785 			struct ip_tunnel_encap *ipencap)
1786 {
1787 	int hlen;
1788 
1789 	memset(&t->encap, 0, sizeof(t->encap));
1790 
1791 	hlen = ip6_encap_hlen(ipencap);
1792 	if (hlen < 0)
1793 		return hlen;
1794 
1795 	t->encap.type = ipencap->type;
1796 	t->encap.sport = ipencap->sport;
1797 	t->encap.dport = ipencap->dport;
1798 	t->encap.flags = ipencap->flags;
1799 
1800 	t->encap_hlen = hlen;
1801 	t->hlen = t->encap_hlen + t->tun_hlen;
1802 
1803 	return 0;
1804 }
1805 EXPORT_SYMBOL_GPL(ip6_tnl_encap_setup);
1806 
1807 static const struct net_device_ops ip6_tnl_netdev_ops = {
1808 	.ndo_init	= ip6_tnl_dev_init,
1809 	.ndo_uninit	= ip6_tnl_dev_uninit,
1810 	.ndo_start_xmit = ip6_tnl_start_xmit,
1811 	.ndo_siocdevprivate = ip6_tnl_siocdevprivate,
1812 	.ndo_change_mtu = ip6_tnl_change_mtu,
1813 	.ndo_get_stats64 = dev_get_tstats64,
1814 	.ndo_get_iflink = ip6_tnl_get_iflink,
1815 };
1816 
1817 #define IPXIPX_FEATURES (NETIF_F_SG |		\
1818 			 NETIF_F_FRAGLIST |	\
1819 			 NETIF_F_HIGHDMA |	\
1820 			 NETIF_F_GSO_SOFTWARE |	\
1821 			 NETIF_F_HW_CSUM)
1822 
1823 /**
1824  * ip6_tnl_dev_setup - setup virtual tunnel device
1825  *   @dev: virtual device associated with tunnel
1826  *
1827  * Description:
1828  *   Initialize function pointers and device parameters
1829  **/
1830 
1831 static void ip6_tnl_dev_setup(struct net_device *dev)
1832 {
1833 	dev->netdev_ops = &ip6_tnl_netdev_ops;
1834 	dev->header_ops = &ip_tunnel_header_ops;
1835 	dev->needs_free_netdev = true;
1836 	dev->priv_destructor = ip6_dev_free;
1837 
1838 	dev->type = ARPHRD_TUNNEL6;
1839 	dev->flags |= IFF_NOARP;
1840 	dev->addr_len = sizeof(struct in6_addr);
1841 	dev->features |= NETIF_F_LLTX;
1842 	netif_keep_dst(dev);
1843 
1844 	dev->features		|= IPXIPX_FEATURES;
1845 	dev->hw_features	|= IPXIPX_FEATURES;
1846 
1847 	/* This perm addr will be used as interface identifier by IPv6 */
1848 	dev->addr_assign_type = NET_ADDR_RANDOM;
1849 	eth_random_addr(dev->perm_addr);
1850 }
1851 
1852 
1853 /**
1854  * ip6_tnl_dev_init_gen - general initializer for all tunnel devices
1855  *   @dev: virtual device associated with tunnel
1856  **/
1857 
1858 static inline int
1859 ip6_tnl_dev_init_gen(struct net_device *dev)
1860 {
1861 	struct ip6_tnl *t = netdev_priv(dev);
1862 	int ret;
1863 	int t_hlen;
1864 
1865 	t->dev = dev;
1866 	t->net = dev_net(dev);
1867 	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1868 	if (!dev->tstats)
1869 		return -ENOMEM;
1870 
1871 	ret = dst_cache_init(&t->dst_cache, GFP_KERNEL);
1872 	if (ret)
1873 		goto free_stats;
1874 
1875 	ret = gro_cells_init(&t->gro_cells, dev);
1876 	if (ret)
1877 		goto destroy_dst;
1878 
1879 	t->tun_hlen = 0;
1880 	t->hlen = t->encap_hlen + t->tun_hlen;
1881 	t_hlen = t->hlen + sizeof(struct ipv6hdr);
1882 
1883 	dev->type = ARPHRD_TUNNEL6;
1884 	dev->hard_header_len = LL_MAX_HEADER + t_hlen;
1885 	dev->mtu = ETH_DATA_LEN - t_hlen;
1886 	if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1887 		dev->mtu -= 8;
1888 	dev->min_mtu = ETH_MIN_MTU;
1889 	dev->max_mtu = IP6_MAX_MTU - dev->hard_header_len;
1890 
1891 	dev_hold_track(dev, &t->dev_tracker, GFP_KERNEL);
1892 	return 0;
1893 
1894 destroy_dst:
1895 	dst_cache_destroy(&t->dst_cache);
1896 free_stats:
1897 	free_percpu(dev->tstats);
1898 	dev->tstats = NULL;
1899 
1900 	return ret;
1901 }
1902 
1903 /**
1904  * ip6_tnl_dev_init - initializer for all non fallback tunnel devices
1905  *   @dev: virtual device associated with tunnel
1906  **/
1907 
1908 static int ip6_tnl_dev_init(struct net_device *dev)
1909 {
1910 	struct ip6_tnl *t = netdev_priv(dev);
1911 	int err = ip6_tnl_dev_init_gen(dev);
1912 
1913 	if (err)
1914 		return err;
1915 	ip6_tnl_link_config(t);
1916 	if (t->parms.collect_md)
1917 		netif_keep_dst(dev);
1918 	return 0;
1919 }
1920 
1921 /**
1922  * ip6_fb_tnl_dev_init - initializer for fallback tunnel device
1923  *   @dev: fallback device
1924  *
1925  * Return: 0
1926  **/
1927 
1928 static int __net_init ip6_fb_tnl_dev_init(struct net_device *dev)
1929 {
1930 	struct ip6_tnl *t = netdev_priv(dev);
1931 	struct net *net = dev_net(dev);
1932 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1933 
1934 	t->parms.proto = IPPROTO_IPV6;
1935 
1936 	rcu_assign_pointer(ip6n->tnls_wc[0], t);
1937 	return 0;
1938 }
1939 
1940 static int ip6_tnl_validate(struct nlattr *tb[], struct nlattr *data[],
1941 			    struct netlink_ext_ack *extack)
1942 {
1943 	u8 proto;
1944 
1945 	if (!data || !data[IFLA_IPTUN_PROTO])
1946 		return 0;
1947 
1948 	proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1949 	if (proto != IPPROTO_IPV6 &&
1950 	    proto != IPPROTO_IPIP &&
1951 	    proto != 0)
1952 		return -EINVAL;
1953 
1954 	return 0;
1955 }
1956 
1957 static void ip6_tnl_netlink_parms(struct nlattr *data[],
1958 				  struct __ip6_tnl_parm *parms)
1959 {
1960 	memset(parms, 0, sizeof(*parms));
1961 
1962 	if (!data)
1963 		return;
1964 
1965 	if (data[IFLA_IPTUN_LINK])
1966 		parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
1967 
1968 	if (data[IFLA_IPTUN_LOCAL])
1969 		parms->laddr = nla_get_in6_addr(data[IFLA_IPTUN_LOCAL]);
1970 
1971 	if (data[IFLA_IPTUN_REMOTE])
1972 		parms->raddr = nla_get_in6_addr(data[IFLA_IPTUN_REMOTE]);
1973 
1974 	if (data[IFLA_IPTUN_TTL])
1975 		parms->hop_limit = nla_get_u8(data[IFLA_IPTUN_TTL]);
1976 
1977 	if (data[IFLA_IPTUN_ENCAP_LIMIT])
1978 		parms->encap_limit = nla_get_u8(data[IFLA_IPTUN_ENCAP_LIMIT]);
1979 
1980 	if (data[IFLA_IPTUN_FLOWINFO])
1981 		parms->flowinfo = nla_get_be32(data[IFLA_IPTUN_FLOWINFO]);
1982 
1983 	if (data[IFLA_IPTUN_FLAGS])
1984 		parms->flags = nla_get_u32(data[IFLA_IPTUN_FLAGS]);
1985 
1986 	if (data[IFLA_IPTUN_PROTO])
1987 		parms->proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1988 
1989 	if (data[IFLA_IPTUN_COLLECT_METADATA])
1990 		parms->collect_md = true;
1991 
1992 	if (data[IFLA_IPTUN_FWMARK])
1993 		parms->fwmark = nla_get_u32(data[IFLA_IPTUN_FWMARK]);
1994 }
1995 
1996 static bool ip6_tnl_netlink_encap_parms(struct nlattr *data[],
1997 					struct ip_tunnel_encap *ipencap)
1998 {
1999 	bool ret = false;
2000 
2001 	memset(ipencap, 0, sizeof(*ipencap));
2002 
2003 	if (!data)
2004 		return ret;
2005 
2006 	if (data[IFLA_IPTUN_ENCAP_TYPE]) {
2007 		ret = true;
2008 		ipencap->type = nla_get_u16(data[IFLA_IPTUN_ENCAP_TYPE]);
2009 	}
2010 
2011 	if (data[IFLA_IPTUN_ENCAP_FLAGS]) {
2012 		ret = true;
2013 		ipencap->flags = nla_get_u16(data[IFLA_IPTUN_ENCAP_FLAGS]);
2014 	}
2015 
2016 	if (data[IFLA_IPTUN_ENCAP_SPORT]) {
2017 		ret = true;
2018 		ipencap->sport = nla_get_be16(data[IFLA_IPTUN_ENCAP_SPORT]);
2019 	}
2020 
2021 	if (data[IFLA_IPTUN_ENCAP_DPORT]) {
2022 		ret = true;
2023 		ipencap->dport = nla_get_be16(data[IFLA_IPTUN_ENCAP_DPORT]);
2024 	}
2025 
2026 	return ret;
2027 }
2028 
2029 static int ip6_tnl_newlink(struct net *src_net, struct net_device *dev,
2030 			   struct nlattr *tb[], struct nlattr *data[],
2031 			   struct netlink_ext_ack *extack)
2032 {
2033 	struct net *net = dev_net(dev);
2034 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2035 	struct ip_tunnel_encap ipencap;
2036 	struct ip6_tnl *nt, *t;
2037 	int err;
2038 
2039 	nt = netdev_priv(dev);
2040 
2041 	if (ip6_tnl_netlink_encap_parms(data, &ipencap)) {
2042 		err = ip6_tnl_encap_setup(nt, &ipencap);
2043 		if (err < 0)
2044 			return err;
2045 	}
2046 
2047 	ip6_tnl_netlink_parms(data, &nt->parms);
2048 
2049 	if (nt->parms.collect_md) {
2050 		if (rtnl_dereference(ip6n->collect_md_tun))
2051 			return -EEXIST;
2052 	} else {
2053 		t = ip6_tnl_locate(net, &nt->parms, 0);
2054 		if (!IS_ERR(t))
2055 			return -EEXIST;
2056 	}
2057 
2058 	err = ip6_tnl_create2(dev);
2059 	if (!err && tb[IFLA_MTU])
2060 		ip6_tnl_change_mtu(dev, nla_get_u32(tb[IFLA_MTU]));
2061 
2062 	return err;
2063 }
2064 
2065 static int ip6_tnl_changelink(struct net_device *dev, struct nlattr *tb[],
2066 			      struct nlattr *data[],
2067 			      struct netlink_ext_ack *extack)
2068 {
2069 	struct ip6_tnl *t = netdev_priv(dev);
2070 	struct __ip6_tnl_parm p;
2071 	struct net *net = t->net;
2072 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2073 	struct ip_tunnel_encap ipencap;
2074 
2075 	if (dev == ip6n->fb_tnl_dev)
2076 		return -EINVAL;
2077 
2078 	if (ip6_tnl_netlink_encap_parms(data, &ipencap)) {
2079 		int err = ip6_tnl_encap_setup(t, &ipencap);
2080 
2081 		if (err < 0)
2082 			return err;
2083 	}
2084 	ip6_tnl_netlink_parms(data, &p);
2085 	if (p.collect_md)
2086 		return -EINVAL;
2087 
2088 	t = ip6_tnl_locate(net, &p, 0);
2089 	if (!IS_ERR(t)) {
2090 		if (t->dev != dev)
2091 			return -EEXIST;
2092 	} else
2093 		t = netdev_priv(dev);
2094 
2095 	return ip6_tnl_update(t, &p);
2096 }
2097 
2098 static void ip6_tnl_dellink(struct net_device *dev, struct list_head *head)
2099 {
2100 	struct net *net = dev_net(dev);
2101 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2102 
2103 	if (dev != ip6n->fb_tnl_dev)
2104 		unregister_netdevice_queue(dev, head);
2105 }
2106 
2107 static size_t ip6_tnl_get_size(const struct net_device *dev)
2108 {
2109 	return
2110 		/* IFLA_IPTUN_LINK */
2111 		nla_total_size(4) +
2112 		/* IFLA_IPTUN_LOCAL */
2113 		nla_total_size(sizeof(struct in6_addr)) +
2114 		/* IFLA_IPTUN_REMOTE */
2115 		nla_total_size(sizeof(struct in6_addr)) +
2116 		/* IFLA_IPTUN_TTL */
2117 		nla_total_size(1) +
2118 		/* IFLA_IPTUN_ENCAP_LIMIT */
2119 		nla_total_size(1) +
2120 		/* IFLA_IPTUN_FLOWINFO */
2121 		nla_total_size(4) +
2122 		/* IFLA_IPTUN_FLAGS */
2123 		nla_total_size(4) +
2124 		/* IFLA_IPTUN_PROTO */
2125 		nla_total_size(1) +
2126 		/* IFLA_IPTUN_ENCAP_TYPE */
2127 		nla_total_size(2) +
2128 		/* IFLA_IPTUN_ENCAP_FLAGS */
2129 		nla_total_size(2) +
2130 		/* IFLA_IPTUN_ENCAP_SPORT */
2131 		nla_total_size(2) +
2132 		/* IFLA_IPTUN_ENCAP_DPORT */
2133 		nla_total_size(2) +
2134 		/* IFLA_IPTUN_COLLECT_METADATA */
2135 		nla_total_size(0) +
2136 		/* IFLA_IPTUN_FWMARK */
2137 		nla_total_size(4) +
2138 		0;
2139 }
2140 
2141 static int ip6_tnl_fill_info(struct sk_buff *skb, const struct net_device *dev)
2142 {
2143 	struct ip6_tnl *tunnel = netdev_priv(dev);
2144 	struct __ip6_tnl_parm *parm = &tunnel->parms;
2145 
2146 	if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
2147 	    nla_put_in6_addr(skb, IFLA_IPTUN_LOCAL, &parm->laddr) ||
2148 	    nla_put_in6_addr(skb, IFLA_IPTUN_REMOTE, &parm->raddr) ||
2149 	    nla_put_u8(skb, IFLA_IPTUN_TTL, parm->hop_limit) ||
2150 	    nla_put_u8(skb, IFLA_IPTUN_ENCAP_LIMIT, parm->encap_limit) ||
2151 	    nla_put_be32(skb, IFLA_IPTUN_FLOWINFO, parm->flowinfo) ||
2152 	    nla_put_u32(skb, IFLA_IPTUN_FLAGS, parm->flags) ||
2153 	    nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->proto) ||
2154 	    nla_put_u32(skb, IFLA_IPTUN_FWMARK, parm->fwmark))
2155 		goto nla_put_failure;
2156 
2157 	if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE, tunnel->encap.type) ||
2158 	    nla_put_be16(skb, IFLA_IPTUN_ENCAP_SPORT, tunnel->encap.sport) ||
2159 	    nla_put_be16(skb, IFLA_IPTUN_ENCAP_DPORT, tunnel->encap.dport) ||
2160 	    nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS, tunnel->encap.flags))
2161 		goto nla_put_failure;
2162 
2163 	if (parm->collect_md)
2164 		if (nla_put_flag(skb, IFLA_IPTUN_COLLECT_METADATA))
2165 			goto nla_put_failure;
2166 
2167 	return 0;
2168 
2169 nla_put_failure:
2170 	return -EMSGSIZE;
2171 }
2172 
2173 struct net *ip6_tnl_get_link_net(const struct net_device *dev)
2174 {
2175 	struct ip6_tnl *tunnel = netdev_priv(dev);
2176 
2177 	return tunnel->net;
2178 }
2179 EXPORT_SYMBOL(ip6_tnl_get_link_net);
2180 
2181 static const struct nla_policy ip6_tnl_policy[IFLA_IPTUN_MAX + 1] = {
2182 	[IFLA_IPTUN_LINK]		= { .type = NLA_U32 },
2183 	[IFLA_IPTUN_LOCAL]		= { .len = sizeof(struct in6_addr) },
2184 	[IFLA_IPTUN_REMOTE]		= { .len = sizeof(struct in6_addr) },
2185 	[IFLA_IPTUN_TTL]		= { .type = NLA_U8 },
2186 	[IFLA_IPTUN_ENCAP_LIMIT]	= { .type = NLA_U8 },
2187 	[IFLA_IPTUN_FLOWINFO]		= { .type = NLA_U32 },
2188 	[IFLA_IPTUN_FLAGS]		= { .type = NLA_U32 },
2189 	[IFLA_IPTUN_PROTO]		= { .type = NLA_U8 },
2190 	[IFLA_IPTUN_ENCAP_TYPE]		= { .type = NLA_U16 },
2191 	[IFLA_IPTUN_ENCAP_FLAGS]	= { .type = NLA_U16 },
2192 	[IFLA_IPTUN_ENCAP_SPORT]	= { .type = NLA_U16 },
2193 	[IFLA_IPTUN_ENCAP_DPORT]	= { .type = NLA_U16 },
2194 	[IFLA_IPTUN_COLLECT_METADATA]	= { .type = NLA_FLAG },
2195 	[IFLA_IPTUN_FWMARK]		= { .type = NLA_U32 },
2196 };
2197 
2198 static struct rtnl_link_ops ip6_link_ops __read_mostly = {
2199 	.kind		= "ip6tnl",
2200 	.maxtype	= IFLA_IPTUN_MAX,
2201 	.policy		= ip6_tnl_policy,
2202 	.priv_size	= sizeof(struct ip6_tnl),
2203 	.setup		= ip6_tnl_dev_setup,
2204 	.validate	= ip6_tnl_validate,
2205 	.newlink	= ip6_tnl_newlink,
2206 	.changelink	= ip6_tnl_changelink,
2207 	.dellink	= ip6_tnl_dellink,
2208 	.get_size	= ip6_tnl_get_size,
2209 	.fill_info	= ip6_tnl_fill_info,
2210 	.get_link_net	= ip6_tnl_get_link_net,
2211 };
2212 
2213 static struct xfrm6_tunnel ip4ip6_handler __read_mostly = {
2214 	.handler	= ip4ip6_rcv,
2215 	.err_handler	= ip4ip6_err,
2216 	.priority	=	1,
2217 };
2218 
2219 static struct xfrm6_tunnel ip6ip6_handler __read_mostly = {
2220 	.handler	= ip6ip6_rcv,
2221 	.err_handler	= ip6ip6_err,
2222 	.priority	=	1,
2223 };
2224 
2225 static struct xfrm6_tunnel mplsip6_handler __read_mostly = {
2226 	.handler	= mplsip6_rcv,
2227 	.err_handler	= mplsip6_err,
2228 	.priority	=	1,
2229 };
2230 
2231 static void __net_exit ip6_tnl_destroy_tunnels(struct net *net, struct list_head *list)
2232 {
2233 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2234 	struct net_device *dev, *aux;
2235 	int h;
2236 	struct ip6_tnl *t;
2237 
2238 	for_each_netdev_safe(net, dev, aux)
2239 		if (dev->rtnl_link_ops == &ip6_link_ops)
2240 			unregister_netdevice_queue(dev, list);
2241 
2242 	for (h = 0; h < IP6_TUNNEL_HASH_SIZE; h++) {
2243 		t = rtnl_dereference(ip6n->tnls_r_l[h]);
2244 		while (t) {
2245 			/* If dev is in the same netns, it has already
2246 			 * been added to the list by the previous loop.
2247 			 */
2248 			if (!net_eq(dev_net(t->dev), net))
2249 				unregister_netdevice_queue(t->dev, list);
2250 			t = rtnl_dereference(t->next);
2251 		}
2252 	}
2253 
2254 	t = rtnl_dereference(ip6n->tnls_wc[0]);
2255 	while (t) {
2256 		/* If dev is in the same netns, it has already
2257 		 * been added to the list by the previous loop.
2258 		 */
2259 		if (!net_eq(dev_net(t->dev), net))
2260 			unregister_netdevice_queue(t->dev, list);
2261 		t = rtnl_dereference(t->next);
2262 	}
2263 }
2264 
2265 static int __net_init ip6_tnl_init_net(struct net *net)
2266 {
2267 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2268 	struct ip6_tnl *t = NULL;
2269 	int err;
2270 
2271 	ip6n->tnls[0] = ip6n->tnls_wc;
2272 	ip6n->tnls[1] = ip6n->tnls_r_l;
2273 
2274 	if (!net_has_fallback_tunnels(net))
2275 		return 0;
2276 	err = -ENOMEM;
2277 	ip6n->fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6tnl0",
2278 					NET_NAME_UNKNOWN, ip6_tnl_dev_setup);
2279 
2280 	if (!ip6n->fb_tnl_dev)
2281 		goto err_alloc_dev;
2282 	dev_net_set(ip6n->fb_tnl_dev, net);
2283 	ip6n->fb_tnl_dev->rtnl_link_ops = &ip6_link_ops;
2284 	/* FB netdevice is special: we have one, and only one per netns.
2285 	 * Allowing to move it to another netns is clearly unsafe.
2286 	 */
2287 	ip6n->fb_tnl_dev->features |= NETIF_F_NETNS_LOCAL;
2288 
2289 	err = ip6_fb_tnl_dev_init(ip6n->fb_tnl_dev);
2290 	if (err < 0)
2291 		goto err_register;
2292 
2293 	err = register_netdev(ip6n->fb_tnl_dev);
2294 	if (err < 0)
2295 		goto err_register;
2296 
2297 	t = netdev_priv(ip6n->fb_tnl_dev);
2298 
2299 	strcpy(t->parms.name, ip6n->fb_tnl_dev->name);
2300 	return 0;
2301 
2302 err_register:
2303 	free_netdev(ip6n->fb_tnl_dev);
2304 err_alloc_dev:
2305 	return err;
2306 }
2307 
2308 static void __net_exit ip6_tnl_exit_batch_net(struct list_head *net_list)
2309 {
2310 	struct net *net;
2311 	LIST_HEAD(list);
2312 
2313 	rtnl_lock();
2314 	list_for_each_entry(net, net_list, exit_list)
2315 		ip6_tnl_destroy_tunnels(net, &list);
2316 	unregister_netdevice_many(&list);
2317 	rtnl_unlock();
2318 }
2319 
2320 static struct pernet_operations ip6_tnl_net_ops = {
2321 	.init = ip6_tnl_init_net,
2322 	.exit_batch = ip6_tnl_exit_batch_net,
2323 	.id   = &ip6_tnl_net_id,
2324 	.size = sizeof(struct ip6_tnl_net),
2325 };
2326 
2327 /**
2328  * ip6_tunnel_init - register protocol and reserve needed resources
2329  *
2330  * Return: 0 on success
2331  **/
2332 
2333 static int __init ip6_tunnel_init(void)
2334 {
2335 	int  err;
2336 
2337 	if (!ipv6_mod_enabled())
2338 		return -EOPNOTSUPP;
2339 
2340 	err = register_pernet_device(&ip6_tnl_net_ops);
2341 	if (err < 0)
2342 		goto out_pernet;
2343 
2344 	err = xfrm6_tunnel_register(&ip4ip6_handler, AF_INET);
2345 	if (err < 0) {
2346 		pr_err("%s: can't register ip4ip6\n", __func__);
2347 		goto out_ip4ip6;
2348 	}
2349 
2350 	err = xfrm6_tunnel_register(&ip6ip6_handler, AF_INET6);
2351 	if (err < 0) {
2352 		pr_err("%s: can't register ip6ip6\n", __func__);
2353 		goto out_ip6ip6;
2354 	}
2355 
2356 	if (ip6_tnl_mpls_supported()) {
2357 		err = xfrm6_tunnel_register(&mplsip6_handler, AF_MPLS);
2358 		if (err < 0) {
2359 			pr_err("%s: can't register mplsip6\n", __func__);
2360 			goto out_mplsip6;
2361 		}
2362 	}
2363 
2364 	err = rtnl_link_register(&ip6_link_ops);
2365 	if (err < 0)
2366 		goto rtnl_link_failed;
2367 
2368 	return 0;
2369 
2370 rtnl_link_failed:
2371 	if (ip6_tnl_mpls_supported())
2372 		xfrm6_tunnel_deregister(&mplsip6_handler, AF_MPLS);
2373 out_mplsip6:
2374 	xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6);
2375 out_ip6ip6:
2376 	xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET);
2377 out_ip4ip6:
2378 	unregister_pernet_device(&ip6_tnl_net_ops);
2379 out_pernet:
2380 	return err;
2381 }
2382 
2383 /**
2384  * ip6_tunnel_cleanup - free resources and unregister protocol
2385  **/
2386 
2387 static void __exit ip6_tunnel_cleanup(void)
2388 {
2389 	rtnl_link_unregister(&ip6_link_ops);
2390 	if (xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET))
2391 		pr_info("%s: can't deregister ip4ip6\n", __func__);
2392 
2393 	if (xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6))
2394 		pr_info("%s: can't deregister ip6ip6\n", __func__);
2395 
2396 	if (ip6_tnl_mpls_supported() &&
2397 	    xfrm6_tunnel_deregister(&mplsip6_handler, AF_MPLS))
2398 		pr_info("%s: can't deregister mplsip6\n", __func__);
2399 	unregister_pernet_device(&ip6_tnl_net_ops);
2400 }
2401 
2402 module_init(ip6_tunnel_init);
2403 module_exit(ip6_tunnel_cleanup);
2404