xref: /openbmc/linux/net/ipv6/ip6_tunnel.c (revision 5e29a910)
1 /*
2  *	IPv6 tunneling device
3  *	Linux INET6 implementation
4  *
5  *	Authors:
6  *	Ville Nuorvala		<vnuorval@tcs.hut.fi>
7  *	Yasuyuki Kozakai	<kozakai@linux-ipv6.org>
8  *
9  *      Based on:
10  *      linux/net/ipv6/sit.c and linux/net/ipv4/ipip.c
11  *
12  *      RFC 2473
13  *
14  *	This program is free software; you can redistribute it and/or
15  *      modify it under the terms of the GNU General Public License
16  *      as published by the Free Software Foundation; either version
17  *      2 of the License, or (at your option) any later version.
18  *
19  */
20 
21 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
22 
23 #include <linux/module.h>
24 #include <linux/capability.h>
25 #include <linux/errno.h>
26 #include <linux/types.h>
27 #include <linux/sockios.h>
28 #include <linux/icmp.h>
29 #include <linux/if.h>
30 #include <linux/in.h>
31 #include <linux/ip.h>
32 #include <linux/net.h>
33 #include <linux/in6.h>
34 #include <linux/netdevice.h>
35 #include <linux/if_arp.h>
36 #include <linux/icmpv6.h>
37 #include <linux/init.h>
38 #include <linux/route.h>
39 #include <linux/rtnetlink.h>
40 #include <linux/netfilter_ipv6.h>
41 #include <linux/slab.h>
42 #include <linux/hash.h>
43 #include <linux/etherdevice.h>
44 
45 #include <asm/uaccess.h>
46 #include <linux/atomic.h>
47 
48 #include <net/icmp.h>
49 #include <net/ip.h>
50 #include <net/ip_tunnels.h>
51 #include <net/ipv6.h>
52 #include <net/ip6_route.h>
53 #include <net/addrconf.h>
54 #include <net/ip6_tunnel.h>
55 #include <net/xfrm.h>
56 #include <net/dsfield.h>
57 #include <net/inet_ecn.h>
58 #include <net/net_namespace.h>
59 #include <net/netns/generic.h>
60 
61 MODULE_AUTHOR("Ville Nuorvala");
62 MODULE_DESCRIPTION("IPv6 tunneling device");
63 MODULE_LICENSE("GPL");
64 MODULE_ALIAS_RTNL_LINK("ip6tnl");
65 MODULE_ALIAS_NETDEV("ip6tnl0");
66 
67 #ifdef IP6_TNL_DEBUG
68 #define IP6_TNL_TRACE(x...) pr_debug("%s:" x "\n", __func__)
69 #else
70 #define IP6_TNL_TRACE(x...) do {;} while(0)
71 #endif
72 
73 #define HASH_SIZE_SHIFT  5
74 #define HASH_SIZE (1 << HASH_SIZE_SHIFT)
75 
76 static bool log_ecn_error = true;
77 module_param(log_ecn_error, bool, 0644);
78 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
79 
80 static u32 HASH(const struct in6_addr *addr1, const struct in6_addr *addr2)
81 {
82 	u32 hash = ipv6_addr_hash(addr1) ^ ipv6_addr_hash(addr2);
83 
84 	return hash_32(hash, HASH_SIZE_SHIFT);
85 }
86 
87 static int ip6_tnl_dev_init(struct net_device *dev);
88 static void ip6_tnl_dev_setup(struct net_device *dev);
89 static struct rtnl_link_ops ip6_link_ops __read_mostly;
90 
91 static int ip6_tnl_net_id __read_mostly;
92 struct ip6_tnl_net {
93 	/* the IPv6 tunnel fallback device */
94 	struct net_device *fb_tnl_dev;
95 	/* lists for storing tunnels in use */
96 	struct ip6_tnl __rcu *tnls_r_l[HASH_SIZE];
97 	struct ip6_tnl __rcu *tnls_wc[1];
98 	struct ip6_tnl __rcu **tnls[2];
99 };
100 
101 static struct net_device_stats *ip6_get_stats(struct net_device *dev)
102 {
103 	struct pcpu_sw_netstats tmp, sum = { 0 };
104 	int i;
105 
106 	for_each_possible_cpu(i) {
107 		unsigned int start;
108 		const struct pcpu_sw_netstats *tstats =
109 						   per_cpu_ptr(dev->tstats, i);
110 
111 		do {
112 			start = u64_stats_fetch_begin_irq(&tstats->syncp);
113 			tmp.rx_packets = tstats->rx_packets;
114 			tmp.rx_bytes = tstats->rx_bytes;
115 			tmp.tx_packets = tstats->tx_packets;
116 			tmp.tx_bytes =  tstats->tx_bytes;
117 		} while (u64_stats_fetch_retry_irq(&tstats->syncp, start));
118 
119 		sum.rx_packets += tmp.rx_packets;
120 		sum.rx_bytes   += tmp.rx_bytes;
121 		sum.tx_packets += tmp.tx_packets;
122 		sum.tx_bytes   += tmp.tx_bytes;
123 	}
124 	dev->stats.rx_packets = sum.rx_packets;
125 	dev->stats.rx_bytes   = sum.rx_bytes;
126 	dev->stats.tx_packets = sum.tx_packets;
127 	dev->stats.tx_bytes   = sum.tx_bytes;
128 	return &dev->stats;
129 }
130 
131 /*
132  * Locking : hash tables are protected by RCU and RTNL
133  */
134 
135 struct dst_entry *ip6_tnl_dst_check(struct ip6_tnl *t)
136 {
137 	struct dst_entry *dst = t->dst_cache;
138 
139 	if (dst && dst->obsolete &&
140 	    dst->ops->check(dst, t->dst_cookie) == NULL) {
141 		t->dst_cache = NULL;
142 		dst_release(dst);
143 		return NULL;
144 	}
145 
146 	return dst;
147 }
148 EXPORT_SYMBOL_GPL(ip6_tnl_dst_check);
149 
150 void ip6_tnl_dst_reset(struct ip6_tnl *t)
151 {
152 	dst_release(t->dst_cache);
153 	t->dst_cache = NULL;
154 }
155 EXPORT_SYMBOL_GPL(ip6_tnl_dst_reset);
156 
157 void ip6_tnl_dst_store(struct ip6_tnl *t, struct dst_entry *dst)
158 {
159 	struct rt6_info *rt = (struct rt6_info *) dst;
160 	t->dst_cookie = rt->rt6i_node ? rt->rt6i_node->fn_sernum : 0;
161 	dst_release(t->dst_cache);
162 	t->dst_cache = dst;
163 }
164 EXPORT_SYMBOL_GPL(ip6_tnl_dst_store);
165 
166 /**
167  * ip6_tnl_lookup - fetch tunnel matching the end-point addresses
168  *   @remote: the address of the tunnel exit-point
169  *   @local: the address of the tunnel entry-point
170  *
171  * Return:
172  *   tunnel matching given end-points if found,
173  *   else fallback tunnel if its device is up,
174  *   else %NULL
175  **/
176 
177 #define for_each_ip6_tunnel_rcu(start) \
178 	for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
179 
180 static struct ip6_tnl *
181 ip6_tnl_lookup(struct net *net, const struct in6_addr *remote, const struct in6_addr *local)
182 {
183 	unsigned int hash = HASH(remote, local);
184 	struct ip6_tnl *t;
185 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
186 	struct in6_addr any;
187 
188 	for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
189 		if (ipv6_addr_equal(local, &t->parms.laddr) &&
190 		    ipv6_addr_equal(remote, &t->parms.raddr) &&
191 		    (t->dev->flags & IFF_UP))
192 			return t;
193 	}
194 
195 	memset(&any, 0, sizeof(any));
196 	hash = HASH(&any, local);
197 	for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
198 		if (ipv6_addr_equal(local, &t->parms.laddr) &&
199 		    (t->dev->flags & IFF_UP))
200 			return t;
201 	}
202 
203 	hash = HASH(remote, &any);
204 	for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
205 		if (ipv6_addr_equal(remote, &t->parms.raddr) &&
206 		    (t->dev->flags & IFF_UP))
207 			return t;
208 	}
209 
210 	t = rcu_dereference(ip6n->tnls_wc[0]);
211 	if (t && (t->dev->flags & IFF_UP))
212 		return t;
213 
214 	return NULL;
215 }
216 
217 /**
218  * ip6_tnl_bucket - get head of list matching given tunnel parameters
219  *   @p: parameters containing tunnel end-points
220  *
221  * Description:
222  *   ip6_tnl_bucket() returns the head of the list matching the
223  *   &struct in6_addr entries laddr and raddr in @p.
224  *
225  * Return: head of IPv6 tunnel list
226  **/
227 
228 static struct ip6_tnl __rcu **
229 ip6_tnl_bucket(struct ip6_tnl_net *ip6n, const struct __ip6_tnl_parm *p)
230 {
231 	const struct in6_addr *remote = &p->raddr;
232 	const struct in6_addr *local = &p->laddr;
233 	unsigned int h = 0;
234 	int prio = 0;
235 
236 	if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) {
237 		prio = 1;
238 		h = HASH(remote, local);
239 	}
240 	return &ip6n->tnls[prio][h];
241 }
242 
243 /**
244  * ip6_tnl_link - add tunnel to hash table
245  *   @t: tunnel to be added
246  **/
247 
248 static void
249 ip6_tnl_link(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
250 {
251 	struct ip6_tnl __rcu **tp = ip6_tnl_bucket(ip6n, &t->parms);
252 
253 	rcu_assign_pointer(t->next , rtnl_dereference(*tp));
254 	rcu_assign_pointer(*tp, t);
255 }
256 
257 /**
258  * ip6_tnl_unlink - remove tunnel from hash table
259  *   @t: tunnel to be removed
260  **/
261 
262 static void
263 ip6_tnl_unlink(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
264 {
265 	struct ip6_tnl __rcu **tp;
266 	struct ip6_tnl *iter;
267 
268 	for (tp = ip6_tnl_bucket(ip6n, &t->parms);
269 	     (iter = rtnl_dereference(*tp)) != NULL;
270 	     tp = &iter->next) {
271 		if (t == iter) {
272 			rcu_assign_pointer(*tp, t->next);
273 			break;
274 		}
275 	}
276 }
277 
278 static void ip6_dev_free(struct net_device *dev)
279 {
280 	free_percpu(dev->tstats);
281 	free_netdev(dev);
282 }
283 
284 static int ip6_tnl_create2(struct net_device *dev)
285 {
286 	struct ip6_tnl *t = netdev_priv(dev);
287 	struct net *net = dev_net(dev);
288 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
289 	int err;
290 
291 	t = netdev_priv(dev);
292 
293 	err = register_netdevice(dev);
294 	if (err < 0)
295 		goto out;
296 
297 	strcpy(t->parms.name, dev->name);
298 	dev->rtnl_link_ops = &ip6_link_ops;
299 
300 	dev_hold(dev);
301 	ip6_tnl_link(ip6n, t);
302 	return 0;
303 
304 out:
305 	return err;
306 }
307 
308 /**
309  * ip6_tnl_create - create a new tunnel
310  *   @p: tunnel parameters
311  *   @pt: pointer to new tunnel
312  *
313  * Description:
314  *   Create tunnel matching given parameters.
315  *
316  * Return:
317  *   created tunnel or NULL
318  **/
319 
320 static struct ip6_tnl *ip6_tnl_create(struct net *net, struct __ip6_tnl_parm *p)
321 {
322 	struct net_device *dev;
323 	struct ip6_tnl *t;
324 	char name[IFNAMSIZ];
325 	int err;
326 
327 	if (p->name[0])
328 		strlcpy(name, p->name, IFNAMSIZ);
329 	else
330 		sprintf(name, "ip6tnl%%d");
331 
332 	dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
333 			   ip6_tnl_dev_setup);
334 	if (dev == NULL)
335 		goto failed;
336 
337 	dev_net_set(dev, net);
338 
339 	t = netdev_priv(dev);
340 	t->parms = *p;
341 	t->net = dev_net(dev);
342 	err = ip6_tnl_create2(dev);
343 	if (err < 0)
344 		goto failed_free;
345 
346 	return t;
347 
348 failed_free:
349 	ip6_dev_free(dev);
350 failed:
351 	return NULL;
352 }
353 
354 /**
355  * ip6_tnl_locate - find or create tunnel matching given parameters
356  *   @p: tunnel parameters
357  *   @create: != 0 if allowed to create new tunnel if no match found
358  *
359  * Description:
360  *   ip6_tnl_locate() first tries to locate an existing tunnel
361  *   based on @parms. If this is unsuccessful, but @create is set a new
362  *   tunnel device is created and registered for use.
363  *
364  * Return:
365  *   matching tunnel or NULL
366  **/
367 
368 static struct ip6_tnl *ip6_tnl_locate(struct net *net,
369 		struct __ip6_tnl_parm *p, int create)
370 {
371 	const struct in6_addr *remote = &p->raddr;
372 	const struct in6_addr *local = &p->laddr;
373 	struct ip6_tnl __rcu **tp;
374 	struct ip6_tnl *t;
375 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
376 
377 	for (tp = ip6_tnl_bucket(ip6n, p);
378 	     (t = rtnl_dereference(*tp)) != NULL;
379 	     tp = &t->next) {
380 		if (ipv6_addr_equal(local, &t->parms.laddr) &&
381 		    ipv6_addr_equal(remote, &t->parms.raddr)) {
382 			if (create)
383 				return NULL;
384 
385 			return t;
386 		}
387 	}
388 	if (!create)
389 		return NULL;
390 	return ip6_tnl_create(net, p);
391 }
392 
393 /**
394  * ip6_tnl_dev_uninit - tunnel device uninitializer
395  *   @dev: the device to be destroyed
396  *
397  * Description:
398  *   ip6_tnl_dev_uninit() removes tunnel from its list
399  **/
400 
401 static void
402 ip6_tnl_dev_uninit(struct net_device *dev)
403 {
404 	struct ip6_tnl *t = netdev_priv(dev);
405 	struct net *net = t->net;
406 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
407 
408 	if (dev == ip6n->fb_tnl_dev)
409 		RCU_INIT_POINTER(ip6n->tnls_wc[0], NULL);
410 	else
411 		ip6_tnl_unlink(ip6n, t);
412 	ip6_tnl_dst_reset(t);
413 	dev_put(dev);
414 }
415 
416 /**
417  * parse_tvl_tnl_enc_lim - handle encapsulation limit option
418  *   @skb: received socket buffer
419  *
420  * Return:
421  *   0 if none was found,
422  *   else index to encapsulation limit
423  **/
424 
425 __u16 ip6_tnl_parse_tlv_enc_lim(struct sk_buff *skb, __u8 *raw)
426 {
427 	const struct ipv6hdr *ipv6h = (const struct ipv6hdr *) raw;
428 	__u8 nexthdr = ipv6h->nexthdr;
429 	__u16 off = sizeof(*ipv6h);
430 
431 	while (ipv6_ext_hdr(nexthdr) && nexthdr != NEXTHDR_NONE) {
432 		__u16 optlen = 0;
433 		struct ipv6_opt_hdr *hdr;
434 		if (raw + off + sizeof(*hdr) > skb->data &&
435 		    !pskb_may_pull(skb, raw - skb->data + off + sizeof (*hdr)))
436 			break;
437 
438 		hdr = (struct ipv6_opt_hdr *) (raw + off);
439 		if (nexthdr == NEXTHDR_FRAGMENT) {
440 			struct frag_hdr *frag_hdr = (struct frag_hdr *) hdr;
441 			if (frag_hdr->frag_off)
442 				break;
443 			optlen = 8;
444 		} else if (nexthdr == NEXTHDR_AUTH) {
445 			optlen = (hdr->hdrlen + 2) << 2;
446 		} else {
447 			optlen = ipv6_optlen(hdr);
448 		}
449 		if (nexthdr == NEXTHDR_DEST) {
450 			__u16 i = off + 2;
451 			while (1) {
452 				struct ipv6_tlv_tnl_enc_lim *tel;
453 
454 				/* No more room for encapsulation limit */
455 				if (i + sizeof (*tel) > off + optlen)
456 					break;
457 
458 				tel = (struct ipv6_tlv_tnl_enc_lim *) &raw[i];
459 				/* return index of option if found and valid */
460 				if (tel->type == IPV6_TLV_TNL_ENCAP_LIMIT &&
461 				    tel->length == 1)
462 					return i;
463 				/* else jump to next option */
464 				if (tel->type)
465 					i += tel->length + 2;
466 				else
467 					i++;
468 			}
469 		}
470 		nexthdr = hdr->nexthdr;
471 		off += optlen;
472 	}
473 	return 0;
474 }
475 EXPORT_SYMBOL(ip6_tnl_parse_tlv_enc_lim);
476 
477 /**
478  * ip6_tnl_err - tunnel error handler
479  *
480  * Description:
481  *   ip6_tnl_err() should handle errors in the tunnel according
482  *   to the specifications in RFC 2473.
483  **/
484 
485 static int
486 ip6_tnl_err(struct sk_buff *skb, __u8 ipproto, struct inet6_skb_parm *opt,
487 	    u8 *type, u8 *code, int *msg, __u32 *info, int offset)
488 {
489 	const struct ipv6hdr *ipv6h = (const struct ipv6hdr *) skb->data;
490 	struct ip6_tnl *t;
491 	int rel_msg = 0;
492 	u8 rel_type = ICMPV6_DEST_UNREACH;
493 	u8 rel_code = ICMPV6_ADDR_UNREACH;
494 	u8 tproto;
495 	__u32 rel_info = 0;
496 	__u16 len;
497 	int err = -ENOENT;
498 
499 	/* If the packet doesn't contain the original IPv6 header we are
500 	   in trouble since we might need the source address for further
501 	   processing of the error. */
502 
503 	rcu_read_lock();
504 	t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->daddr, &ipv6h->saddr);
505 	if (t == NULL)
506 		goto out;
507 
508 	tproto = ACCESS_ONCE(t->parms.proto);
509 	if (tproto != ipproto && tproto != 0)
510 		goto out;
511 
512 	err = 0;
513 
514 	switch (*type) {
515 		__u32 teli;
516 		struct ipv6_tlv_tnl_enc_lim *tel;
517 		__u32 mtu;
518 	case ICMPV6_DEST_UNREACH:
519 		net_warn_ratelimited("%s: Path to destination invalid or inactive!\n",
520 				     t->parms.name);
521 		rel_msg = 1;
522 		break;
523 	case ICMPV6_TIME_EXCEED:
524 		if ((*code) == ICMPV6_EXC_HOPLIMIT) {
525 			net_warn_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
526 					     t->parms.name);
527 			rel_msg = 1;
528 		}
529 		break;
530 	case ICMPV6_PARAMPROB:
531 		teli = 0;
532 		if ((*code) == ICMPV6_HDR_FIELD)
533 			teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
534 
535 		if (teli && teli == *info - 2) {
536 			tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
537 			if (tel->encap_limit == 0) {
538 				net_warn_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
539 						     t->parms.name);
540 				rel_msg = 1;
541 			}
542 		} else {
543 			net_warn_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
544 					     t->parms.name);
545 		}
546 		break;
547 	case ICMPV6_PKT_TOOBIG:
548 		mtu = *info - offset;
549 		if (mtu < IPV6_MIN_MTU)
550 			mtu = IPV6_MIN_MTU;
551 		t->dev->mtu = mtu;
552 
553 		len = sizeof(*ipv6h) + ntohs(ipv6h->payload_len);
554 		if (len > mtu) {
555 			rel_type = ICMPV6_PKT_TOOBIG;
556 			rel_code = 0;
557 			rel_info = mtu;
558 			rel_msg = 1;
559 		}
560 		break;
561 	}
562 
563 	*type = rel_type;
564 	*code = rel_code;
565 	*info = rel_info;
566 	*msg = rel_msg;
567 
568 out:
569 	rcu_read_unlock();
570 	return err;
571 }
572 
573 static int
574 ip4ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
575 	   u8 type, u8 code, int offset, __be32 info)
576 {
577 	int rel_msg = 0;
578 	u8 rel_type = type;
579 	u8 rel_code = code;
580 	__u32 rel_info = ntohl(info);
581 	int err;
582 	struct sk_buff *skb2;
583 	const struct iphdr *eiph;
584 	struct rtable *rt;
585 	struct flowi4 fl4;
586 
587 	err = ip6_tnl_err(skb, IPPROTO_IPIP, opt, &rel_type, &rel_code,
588 			  &rel_msg, &rel_info, offset);
589 	if (err < 0)
590 		return err;
591 
592 	if (rel_msg == 0)
593 		return 0;
594 
595 	switch (rel_type) {
596 	case ICMPV6_DEST_UNREACH:
597 		if (rel_code != ICMPV6_ADDR_UNREACH)
598 			return 0;
599 		rel_type = ICMP_DEST_UNREACH;
600 		rel_code = ICMP_HOST_UNREACH;
601 		break;
602 	case ICMPV6_PKT_TOOBIG:
603 		if (rel_code != 0)
604 			return 0;
605 		rel_type = ICMP_DEST_UNREACH;
606 		rel_code = ICMP_FRAG_NEEDED;
607 		break;
608 	case NDISC_REDIRECT:
609 		rel_type = ICMP_REDIRECT;
610 		rel_code = ICMP_REDIR_HOST;
611 	default:
612 		return 0;
613 	}
614 
615 	if (!pskb_may_pull(skb, offset + sizeof(struct iphdr)))
616 		return 0;
617 
618 	skb2 = skb_clone(skb, GFP_ATOMIC);
619 	if (!skb2)
620 		return 0;
621 
622 	skb_dst_drop(skb2);
623 
624 	skb_pull(skb2, offset);
625 	skb_reset_network_header(skb2);
626 	eiph = ip_hdr(skb2);
627 
628 	/* Try to guess incoming interface */
629 	rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL,
630 				   eiph->saddr, 0,
631 				   0, 0,
632 				   IPPROTO_IPIP, RT_TOS(eiph->tos), 0);
633 	if (IS_ERR(rt))
634 		goto out;
635 
636 	skb2->dev = rt->dst.dev;
637 
638 	/* route "incoming" packet */
639 	if (rt->rt_flags & RTCF_LOCAL) {
640 		ip_rt_put(rt);
641 		rt = NULL;
642 		rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL,
643 					   eiph->daddr, eiph->saddr,
644 					   0, 0,
645 					   IPPROTO_IPIP,
646 					   RT_TOS(eiph->tos), 0);
647 		if (IS_ERR(rt) ||
648 		    rt->dst.dev->type != ARPHRD_TUNNEL) {
649 			if (!IS_ERR(rt))
650 				ip_rt_put(rt);
651 			goto out;
652 		}
653 		skb_dst_set(skb2, &rt->dst);
654 	} else {
655 		ip_rt_put(rt);
656 		if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos,
657 				   skb2->dev) ||
658 		    skb_dst(skb2)->dev->type != ARPHRD_TUNNEL)
659 			goto out;
660 	}
661 
662 	/* change mtu on this route */
663 	if (rel_type == ICMP_DEST_UNREACH && rel_code == ICMP_FRAG_NEEDED) {
664 		if (rel_info > dst_mtu(skb_dst(skb2)))
665 			goto out;
666 
667 		skb_dst(skb2)->ops->update_pmtu(skb_dst(skb2), NULL, skb2, rel_info);
668 	}
669 	if (rel_type == ICMP_REDIRECT)
670 		skb_dst(skb2)->ops->redirect(skb_dst(skb2), NULL, skb2);
671 
672 	icmp_send(skb2, rel_type, rel_code, htonl(rel_info));
673 
674 out:
675 	kfree_skb(skb2);
676 	return 0;
677 }
678 
679 static int
680 ip6ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
681 	   u8 type, u8 code, int offset, __be32 info)
682 {
683 	int rel_msg = 0;
684 	u8 rel_type = type;
685 	u8 rel_code = code;
686 	__u32 rel_info = ntohl(info);
687 	int err;
688 
689 	err = ip6_tnl_err(skb, IPPROTO_IPV6, opt, &rel_type, &rel_code,
690 			  &rel_msg, &rel_info, offset);
691 	if (err < 0)
692 		return err;
693 
694 	if (rel_msg && pskb_may_pull(skb, offset + sizeof(struct ipv6hdr))) {
695 		struct rt6_info *rt;
696 		struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
697 
698 		if (!skb2)
699 			return 0;
700 
701 		skb_dst_drop(skb2);
702 		skb_pull(skb2, offset);
703 		skb_reset_network_header(skb2);
704 
705 		/* Try to guess incoming interface */
706 		rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr,
707 				NULL, 0, 0);
708 
709 		if (rt && rt->dst.dev)
710 			skb2->dev = rt->dst.dev;
711 
712 		icmpv6_send(skb2, rel_type, rel_code, rel_info);
713 
714 		ip6_rt_put(rt);
715 
716 		kfree_skb(skb2);
717 	}
718 
719 	return 0;
720 }
721 
722 static int ip4ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
723 				       const struct ipv6hdr *ipv6h,
724 				       struct sk_buff *skb)
725 {
726 	__u8 dsfield = ipv6_get_dsfield(ipv6h) & ~INET_ECN_MASK;
727 
728 	if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
729 		ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, dsfield);
730 
731 	return IP6_ECN_decapsulate(ipv6h, skb);
732 }
733 
734 static int ip6ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
735 				       const struct ipv6hdr *ipv6h,
736 				       struct sk_buff *skb)
737 {
738 	if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
739 		ipv6_copy_dscp(ipv6_get_dsfield(ipv6h), ipv6_hdr(skb));
740 
741 	return IP6_ECN_decapsulate(ipv6h, skb);
742 }
743 
744 __u32 ip6_tnl_get_cap(struct ip6_tnl *t,
745 			     const struct in6_addr *laddr,
746 			     const struct in6_addr *raddr)
747 {
748 	struct __ip6_tnl_parm *p = &t->parms;
749 	int ltype = ipv6_addr_type(laddr);
750 	int rtype = ipv6_addr_type(raddr);
751 	__u32 flags = 0;
752 
753 	if (ltype == IPV6_ADDR_ANY || rtype == IPV6_ADDR_ANY) {
754 		flags = IP6_TNL_F_CAP_PER_PACKET;
755 	} else if (ltype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
756 		   rtype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
757 		   !((ltype|rtype) & IPV6_ADDR_LOOPBACK) &&
758 		   (!((ltype|rtype) & IPV6_ADDR_LINKLOCAL) || p->link)) {
759 		if (ltype&IPV6_ADDR_UNICAST)
760 			flags |= IP6_TNL_F_CAP_XMIT;
761 		if (rtype&IPV6_ADDR_UNICAST)
762 			flags |= IP6_TNL_F_CAP_RCV;
763 	}
764 	return flags;
765 }
766 EXPORT_SYMBOL(ip6_tnl_get_cap);
767 
768 /* called with rcu_read_lock() */
769 int ip6_tnl_rcv_ctl(struct ip6_tnl *t,
770 				  const struct in6_addr *laddr,
771 				  const struct in6_addr *raddr)
772 {
773 	struct __ip6_tnl_parm *p = &t->parms;
774 	int ret = 0;
775 	struct net *net = t->net;
776 
777 	if ((p->flags & IP6_TNL_F_CAP_RCV) ||
778 	    ((p->flags & IP6_TNL_F_CAP_PER_PACKET) &&
779 	     (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_RCV))) {
780 		struct net_device *ldev = NULL;
781 
782 		if (p->link)
783 			ldev = dev_get_by_index_rcu(net, p->link);
784 
785 		if ((ipv6_addr_is_multicast(laddr) ||
786 		     likely(ipv6_chk_addr(net, laddr, ldev, 0))) &&
787 		    likely(!ipv6_chk_addr(net, raddr, NULL, 0)))
788 			ret = 1;
789 	}
790 	return ret;
791 }
792 EXPORT_SYMBOL_GPL(ip6_tnl_rcv_ctl);
793 
794 /**
795  * ip6_tnl_rcv - decapsulate IPv6 packet and retransmit it locally
796  *   @skb: received socket buffer
797  *   @protocol: ethernet protocol ID
798  *   @dscp_ecn_decapsulate: the function to decapsulate DSCP code and ECN
799  *
800  * Return: 0
801  **/
802 
803 static int ip6_tnl_rcv(struct sk_buff *skb, __u16 protocol,
804 		       __u8 ipproto,
805 		       int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
806 						   const struct ipv6hdr *ipv6h,
807 						   struct sk_buff *skb))
808 {
809 	struct ip6_tnl *t;
810 	const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
811 	u8 tproto;
812 	int err;
813 
814 	rcu_read_lock();
815 	t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->saddr, &ipv6h->daddr);
816 	if (t != NULL) {
817 		struct pcpu_sw_netstats *tstats;
818 
819 		tproto = ACCESS_ONCE(t->parms.proto);
820 		if (tproto != ipproto && tproto != 0) {
821 			rcu_read_unlock();
822 			goto discard;
823 		}
824 
825 		if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
826 			rcu_read_unlock();
827 			goto discard;
828 		}
829 
830 		if (!ip6_tnl_rcv_ctl(t, &ipv6h->daddr, &ipv6h->saddr)) {
831 			t->dev->stats.rx_dropped++;
832 			rcu_read_unlock();
833 			goto discard;
834 		}
835 		skb->mac_header = skb->network_header;
836 		skb_reset_network_header(skb);
837 		skb->protocol = htons(protocol);
838 		memset(skb->cb, 0, sizeof(struct inet6_skb_parm));
839 
840 		__skb_tunnel_rx(skb, t->dev, t->net);
841 
842 		err = dscp_ecn_decapsulate(t, ipv6h, skb);
843 		if (unlikely(err)) {
844 			if (log_ecn_error)
845 				net_info_ratelimited("non-ECT from %pI6 with dsfield=%#x\n",
846 						     &ipv6h->saddr,
847 						     ipv6_get_dsfield(ipv6h));
848 			if (err > 1) {
849 				++t->dev->stats.rx_frame_errors;
850 				++t->dev->stats.rx_errors;
851 				rcu_read_unlock();
852 				goto discard;
853 			}
854 		}
855 
856 		tstats = this_cpu_ptr(t->dev->tstats);
857 		u64_stats_update_begin(&tstats->syncp);
858 		tstats->rx_packets++;
859 		tstats->rx_bytes += skb->len;
860 		u64_stats_update_end(&tstats->syncp);
861 
862 		netif_rx(skb);
863 
864 		rcu_read_unlock();
865 		return 0;
866 	}
867 	rcu_read_unlock();
868 	return 1;
869 
870 discard:
871 	kfree_skb(skb);
872 	return 0;
873 }
874 
875 static int ip4ip6_rcv(struct sk_buff *skb)
876 {
877 	return ip6_tnl_rcv(skb, ETH_P_IP, IPPROTO_IPIP,
878 			   ip4ip6_dscp_ecn_decapsulate);
879 }
880 
881 static int ip6ip6_rcv(struct sk_buff *skb)
882 {
883 	return ip6_tnl_rcv(skb, ETH_P_IPV6, IPPROTO_IPV6,
884 			   ip6ip6_dscp_ecn_decapsulate);
885 }
886 
887 struct ipv6_tel_txoption {
888 	struct ipv6_txoptions ops;
889 	__u8 dst_opt[8];
890 };
891 
892 static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit)
893 {
894 	memset(opt, 0, sizeof(struct ipv6_tel_txoption));
895 
896 	opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT;
897 	opt->dst_opt[3] = 1;
898 	opt->dst_opt[4] = encap_limit;
899 	opt->dst_opt[5] = IPV6_TLV_PADN;
900 	opt->dst_opt[6] = 1;
901 
902 	opt->ops.dst0opt = (struct ipv6_opt_hdr *) opt->dst_opt;
903 	opt->ops.opt_nflen = 8;
904 }
905 
906 /**
907  * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
908  *   @t: the outgoing tunnel device
909  *   @hdr: IPv6 header from the incoming packet
910  *
911  * Description:
912  *   Avoid trivial tunneling loop by checking that tunnel exit-point
913  *   doesn't match source of incoming packet.
914  *
915  * Return:
916  *   1 if conflict,
917  *   0 else
918  **/
919 
920 static inline bool
921 ip6_tnl_addr_conflict(const struct ip6_tnl *t, const struct ipv6hdr *hdr)
922 {
923 	return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
924 }
925 
926 int ip6_tnl_xmit_ctl(struct ip6_tnl *t,
927 		     const struct in6_addr *laddr,
928 		     const struct in6_addr *raddr)
929 {
930 	struct __ip6_tnl_parm *p = &t->parms;
931 	int ret = 0;
932 	struct net *net = t->net;
933 
934 	if ((p->flags & IP6_TNL_F_CAP_XMIT) ||
935 	    ((p->flags & IP6_TNL_F_CAP_PER_PACKET) &&
936 	     (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_XMIT))) {
937 		struct net_device *ldev = NULL;
938 
939 		rcu_read_lock();
940 		if (p->link)
941 			ldev = dev_get_by_index_rcu(net, p->link);
942 
943 		if (unlikely(!ipv6_chk_addr(net, laddr, ldev, 0)))
944 			pr_warn("%s xmit: Local address not yet configured!\n",
945 				p->name);
946 		else if (!ipv6_addr_is_multicast(raddr) &&
947 			 unlikely(ipv6_chk_addr(net, raddr, NULL, 0)))
948 			pr_warn("%s xmit: Routing loop! Remote address found on this node!\n",
949 				p->name);
950 		else
951 			ret = 1;
952 		rcu_read_unlock();
953 	}
954 	return ret;
955 }
956 EXPORT_SYMBOL_GPL(ip6_tnl_xmit_ctl);
957 
958 /**
959  * ip6_tnl_xmit2 - encapsulate packet and send
960  *   @skb: the outgoing socket buffer
961  *   @dev: the outgoing tunnel device
962  *   @dsfield: dscp code for outer header
963  *   @fl: flow of tunneled packet
964  *   @encap_limit: encapsulation limit
965  *   @pmtu: Path MTU is stored if packet is too big
966  *
967  * Description:
968  *   Build new header and do some sanity checks on the packet before sending
969  *   it.
970  *
971  * Return:
972  *   0 on success
973  *   -1 fail
974  *   %-EMSGSIZE message too big. return mtu in this case.
975  **/
976 
977 static int ip6_tnl_xmit2(struct sk_buff *skb,
978 			 struct net_device *dev,
979 			 __u8 dsfield,
980 			 struct flowi6 *fl6,
981 			 int encap_limit,
982 			 __u32 *pmtu)
983 {
984 	struct ip6_tnl *t = netdev_priv(dev);
985 	struct net *net = t->net;
986 	struct net_device_stats *stats = &t->dev->stats;
987 	struct ipv6hdr *ipv6h = ipv6_hdr(skb);
988 	struct ipv6_tel_txoption opt;
989 	struct dst_entry *dst = NULL, *ndst = NULL;
990 	struct net_device *tdev;
991 	int mtu;
992 	unsigned int max_headroom = sizeof(struct ipv6hdr);
993 	u8 proto;
994 	int err = -1;
995 
996 	/* NBMA tunnel */
997 	if (ipv6_addr_any(&t->parms.raddr)) {
998 		struct in6_addr *addr6;
999 		struct neighbour *neigh;
1000 		int addr_type;
1001 
1002 		if (!skb_dst(skb))
1003 			goto tx_err_link_failure;
1004 
1005 		neigh = dst_neigh_lookup(skb_dst(skb),
1006 					 &ipv6_hdr(skb)->daddr);
1007 		if (!neigh)
1008 			goto tx_err_link_failure;
1009 
1010 		addr6 = (struct in6_addr *)&neigh->primary_key;
1011 		addr_type = ipv6_addr_type(addr6);
1012 
1013 		if (addr_type == IPV6_ADDR_ANY)
1014 			addr6 = &ipv6_hdr(skb)->daddr;
1015 
1016 		memcpy(&fl6->daddr, addr6, sizeof(fl6->daddr));
1017 		neigh_release(neigh);
1018 	} else if (!fl6->flowi6_mark)
1019 		dst = ip6_tnl_dst_check(t);
1020 
1021 	if (!ip6_tnl_xmit_ctl(t, &fl6->saddr, &fl6->daddr))
1022 		goto tx_err_link_failure;
1023 
1024 	if (!dst) {
1025 		ndst = ip6_route_output(net, NULL, fl6);
1026 
1027 		if (ndst->error)
1028 			goto tx_err_link_failure;
1029 		ndst = xfrm_lookup(net, ndst, flowi6_to_flowi(fl6), NULL, 0);
1030 		if (IS_ERR(ndst)) {
1031 			err = PTR_ERR(ndst);
1032 			ndst = NULL;
1033 			goto tx_err_link_failure;
1034 		}
1035 		dst = ndst;
1036 	}
1037 
1038 	tdev = dst->dev;
1039 
1040 	if (tdev == dev) {
1041 		stats->collisions++;
1042 		net_warn_ratelimited("%s: Local routing loop detected!\n",
1043 				     t->parms.name);
1044 		goto tx_err_dst_release;
1045 	}
1046 	mtu = dst_mtu(dst) - sizeof(*ipv6h);
1047 	if (encap_limit >= 0) {
1048 		max_headroom += 8;
1049 		mtu -= 8;
1050 	}
1051 	if (mtu < IPV6_MIN_MTU)
1052 		mtu = IPV6_MIN_MTU;
1053 	if (skb_dst(skb))
1054 		skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
1055 	if (skb->len > mtu) {
1056 		*pmtu = mtu;
1057 		err = -EMSGSIZE;
1058 		goto tx_err_dst_release;
1059 	}
1060 
1061 	skb_scrub_packet(skb, !net_eq(t->net, dev_net(dev)));
1062 
1063 	/*
1064 	 * Okay, now see if we can stuff it in the buffer as-is.
1065 	 */
1066 	max_headroom += LL_RESERVED_SPACE(tdev);
1067 
1068 	if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
1069 	    (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
1070 		struct sk_buff *new_skb;
1071 
1072 		new_skb = skb_realloc_headroom(skb, max_headroom);
1073 		if (!new_skb)
1074 			goto tx_err_dst_release;
1075 
1076 		if (skb->sk)
1077 			skb_set_owner_w(new_skb, skb->sk);
1078 		consume_skb(skb);
1079 		skb = new_skb;
1080 	}
1081 	if (fl6->flowi6_mark) {
1082 		skb_dst_set(skb, dst);
1083 		ndst = NULL;
1084 	} else {
1085 		skb_dst_set_noref(skb, dst);
1086 	}
1087 	skb->transport_header = skb->network_header;
1088 
1089 	proto = fl6->flowi6_proto;
1090 	if (encap_limit >= 0) {
1091 		init_tel_txopt(&opt, encap_limit);
1092 		ipv6_push_nfrag_opts(skb, &opt.ops, &proto, NULL);
1093 	}
1094 
1095 	if (likely(!skb->encapsulation)) {
1096 		skb_reset_inner_headers(skb);
1097 		skb->encapsulation = 1;
1098 	}
1099 
1100 	skb_push(skb, sizeof(struct ipv6hdr));
1101 	skb_reset_network_header(skb);
1102 	ipv6h = ipv6_hdr(skb);
1103 	ip6_flow_hdr(ipv6h, INET_ECN_encapsulate(0, dsfield),
1104 		     ip6_make_flowlabel(net, skb, fl6->flowlabel, false));
1105 	ipv6h->hop_limit = t->parms.hop_limit;
1106 	ipv6h->nexthdr = proto;
1107 	ipv6h->saddr = fl6->saddr;
1108 	ipv6h->daddr = fl6->daddr;
1109 	ip6tunnel_xmit(skb, dev);
1110 	if (ndst)
1111 		ip6_tnl_dst_store(t, ndst);
1112 	return 0;
1113 tx_err_link_failure:
1114 	stats->tx_carrier_errors++;
1115 	dst_link_failure(skb);
1116 tx_err_dst_release:
1117 	dst_release(ndst);
1118 	return err;
1119 }
1120 
1121 static inline int
1122 ip4ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1123 {
1124 	struct ip6_tnl *t = netdev_priv(dev);
1125 	const struct iphdr  *iph = ip_hdr(skb);
1126 	int encap_limit = -1;
1127 	struct flowi6 fl6;
1128 	__u8 dsfield;
1129 	__u32 mtu;
1130 	u8 tproto;
1131 	int err;
1132 
1133 	tproto = ACCESS_ONCE(t->parms.proto);
1134 	if (tproto != IPPROTO_IPIP && tproto != 0)
1135 		return -1;
1136 
1137 	if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1138 		encap_limit = t->parms.encap_limit;
1139 
1140 	memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
1141 	fl6.flowi6_proto = IPPROTO_IPIP;
1142 
1143 	dsfield = ipv4_get_dsfield(iph);
1144 
1145 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1146 		fl6.flowlabel |= htonl((__u32)iph->tos << IPV6_TCLASS_SHIFT)
1147 					  & IPV6_TCLASS_MASK;
1148 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
1149 		fl6.flowi6_mark = skb->mark;
1150 
1151 	err = ip6_tnl_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
1152 	if (err != 0) {
1153 		/* XXX: send ICMP error even if DF is not set. */
1154 		if (err == -EMSGSIZE)
1155 			icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
1156 				  htonl(mtu));
1157 		return -1;
1158 	}
1159 
1160 	return 0;
1161 }
1162 
1163 static inline int
1164 ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1165 {
1166 	struct ip6_tnl *t = netdev_priv(dev);
1167 	struct ipv6hdr *ipv6h = ipv6_hdr(skb);
1168 	int encap_limit = -1;
1169 	__u16 offset;
1170 	struct flowi6 fl6;
1171 	__u8 dsfield;
1172 	__u32 mtu;
1173 	u8 tproto;
1174 	int err;
1175 
1176 	tproto = ACCESS_ONCE(t->parms.proto);
1177 	if ((tproto != IPPROTO_IPV6 && tproto != 0) ||
1178 	    ip6_tnl_addr_conflict(t, ipv6h))
1179 		return -1;
1180 
1181 	offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
1182 	if (offset > 0) {
1183 		struct ipv6_tlv_tnl_enc_lim *tel;
1184 		tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset];
1185 		if (tel->encap_limit == 0) {
1186 			icmpv6_send(skb, ICMPV6_PARAMPROB,
1187 				    ICMPV6_HDR_FIELD, offset + 2);
1188 			return -1;
1189 		}
1190 		encap_limit = tel->encap_limit - 1;
1191 	} else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1192 		encap_limit = t->parms.encap_limit;
1193 
1194 	memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
1195 	fl6.flowi6_proto = IPPROTO_IPV6;
1196 
1197 	dsfield = ipv6_get_dsfield(ipv6h);
1198 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1199 		fl6.flowlabel |= (*(__be32 *) ipv6h & IPV6_TCLASS_MASK);
1200 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
1201 		fl6.flowlabel |= ip6_flowlabel(ipv6h);
1202 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
1203 		fl6.flowi6_mark = skb->mark;
1204 
1205 	err = ip6_tnl_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
1206 	if (err != 0) {
1207 		if (err == -EMSGSIZE)
1208 			icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
1209 		return -1;
1210 	}
1211 
1212 	return 0;
1213 }
1214 
1215 static netdev_tx_t
1216 ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1217 {
1218 	struct ip6_tnl *t = netdev_priv(dev);
1219 	struct net_device_stats *stats = &t->dev->stats;
1220 	int ret;
1221 
1222 	switch (skb->protocol) {
1223 	case htons(ETH_P_IP):
1224 		ret = ip4ip6_tnl_xmit(skb, dev);
1225 		break;
1226 	case htons(ETH_P_IPV6):
1227 		ret = ip6ip6_tnl_xmit(skb, dev);
1228 		break;
1229 	default:
1230 		goto tx_err;
1231 	}
1232 
1233 	if (ret < 0)
1234 		goto tx_err;
1235 
1236 	return NETDEV_TX_OK;
1237 
1238 tx_err:
1239 	stats->tx_errors++;
1240 	stats->tx_dropped++;
1241 	kfree_skb(skb);
1242 	return NETDEV_TX_OK;
1243 }
1244 
1245 static void ip6_tnl_link_config(struct ip6_tnl *t)
1246 {
1247 	struct net_device *dev = t->dev;
1248 	struct __ip6_tnl_parm *p = &t->parms;
1249 	struct flowi6 *fl6 = &t->fl.u.ip6;
1250 
1251 	memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
1252 	memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
1253 
1254 	/* Set up flowi template */
1255 	fl6->saddr = p->laddr;
1256 	fl6->daddr = p->raddr;
1257 	fl6->flowi6_oif = p->link;
1258 	fl6->flowlabel = 0;
1259 
1260 	if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
1261 		fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
1262 	if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
1263 		fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
1264 
1265 	p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
1266 	p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
1267 
1268 	if (p->flags&IP6_TNL_F_CAP_XMIT && p->flags&IP6_TNL_F_CAP_RCV)
1269 		dev->flags |= IFF_POINTOPOINT;
1270 	else
1271 		dev->flags &= ~IFF_POINTOPOINT;
1272 
1273 	dev->iflink = p->link;
1274 
1275 	if (p->flags & IP6_TNL_F_CAP_XMIT) {
1276 		int strict = (ipv6_addr_type(&p->raddr) &
1277 			      (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
1278 
1279 		struct rt6_info *rt = rt6_lookup(t->net,
1280 						 &p->raddr, &p->laddr,
1281 						 p->link, strict);
1282 
1283 		if (rt == NULL)
1284 			return;
1285 
1286 		if (rt->dst.dev) {
1287 			dev->hard_header_len = rt->dst.dev->hard_header_len +
1288 				sizeof(struct ipv6hdr);
1289 
1290 			dev->mtu = rt->dst.dev->mtu - sizeof(struct ipv6hdr);
1291 			if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1292 				dev->mtu -= 8;
1293 
1294 			if (dev->mtu < IPV6_MIN_MTU)
1295 				dev->mtu = IPV6_MIN_MTU;
1296 		}
1297 		ip6_rt_put(rt);
1298 	}
1299 }
1300 
1301 /**
1302  * ip6_tnl_change - update the tunnel parameters
1303  *   @t: tunnel to be changed
1304  *   @p: tunnel configuration parameters
1305  *
1306  * Description:
1307  *   ip6_tnl_change() updates the tunnel parameters
1308  **/
1309 
1310 static int
1311 ip6_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p)
1312 {
1313 	t->parms.laddr = p->laddr;
1314 	t->parms.raddr = p->raddr;
1315 	t->parms.flags = p->flags;
1316 	t->parms.hop_limit = p->hop_limit;
1317 	t->parms.encap_limit = p->encap_limit;
1318 	t->parms.flowinfo = p->flowinfo;
1319 	t->parms.link = p->link;
1320 	t->parms.proto = p->proto;
1321 	ip6_tnl_dst_reset(t);
1322 	ip6_tnl_link_config(t);
1323 	return 0;
1324 }
1325 
1326 static int ip6_tnl_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
1327 {
1328 	struct net *net = t->net;
1329 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1330 	int err;
1331 
1332 	ip6_tnl_unlink(ip6n, t);
1333 	synchronize_net();
1334 	err = ip6_tnl_change(t, p);
1335 	ip6_tnl_link(ip6n, t);
1336 	netdev_state_change(t->dev);
1337 	return err;
1338 }
1339 
1340 static int ip6_tnl0_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
1341 {
1342 	/* for default tnl0 device allow to change only the proto */
1343 	t->parms.proto = p->proto;
1344 	netdev_state_change(t->dev);
1345 	return 0;
1346 }
1347 
1348 static void
1349 ip6_tnl_parm_from_user(struct __ip6_tnl_parm *p, const struct ip6_tnl_parm *u)
1350 {
1351 	p->laddr = u->laddr;
1352 	p->raddr = u->raddr;
1353 	p->flags = u->flags;
1354 	p->hop_limit = u->hop_limit;
1355 	p->encap_limit = u->encap_limit;
1356 	p->flowinfo = u->flowinfo;
1357 	p->link = u->link;
1358 	p->proto = u->proto;
1359 	memcpy(p->name, u->name, sizeof(u->name));
1360 }
1361 
1362 static void
1363 ip6_tnl_parm_to_user(struct ip6_tnl_parm *u, const struct __ip6_tnl_parm *p)
1364 {
1365 	u->laddr = p->laddr;
1366 	u->raddr = p->raddr;
1367 	u->flags = p->flags;
1368 	u->hop_limit = p->hop_limit;
1369 	u->encap_limit = p->encap_limit;
1370 	u->flowinfo = p->flowinfo;
1371 	u->link = p->link;
1372 	u->proto = p->proto;
1373 	memcpy(u->name, p->name, sizeof(u->name));
1374 }
1375 
1376 /**
1377  * ip6_tnl_ioctl - configure ipv6 tunnels from userspace
1378  *   @dev: virtual device associated with tunnel
1379  *   @ifr: parameters passed from userspace
1380  *   @cmd: command to be performed
1381  *
1382  * Description:
1383  *   ip6_tnl_ioctl() is used for managing IPv6 tunnels
1384  *   from userspace.
1385  *
1386  *   The possible commands are the following:
1387  *     %SIOCGETTUNNEL: get tunnel parameters for device
1388  *     %SIOCADDTUNNEL: add tunnel matching given tunnel parameters
1389  *     %SIOCCHGTUNNEL: change tunnel parameters to those given
1390  *     %SIOCDELTUNNEL: delete tunnel
1391  *
1392  *   The fallback device "ip6tnl0", created during module
1393  *   initialization, can be used for creating other tunnel devices.
1394  *
1395  * Return:
1396  *   0 on success,
1397  *   %-EFAULT if unable to copy data to or from userspace,
1398  *   %-EPERM if current process hasn't %CAP_NET_ADMIN set
1399  *   %-EINVAL if passed tunnel parameters are invalid,
1400  *   %-EEXIST if changing a tunnel's parameters would cause a conflict
1401  *   %-ENODEV if attempting to change or delete a nonexisting device
1402  **/
1403 
1404 static int
1405 ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1406 {
1407 	int err = 0;
1408 	struct ip6_tnl_parm p;
1409 	struct __ip6_tnl_parm p1;
1410 	struct ip6_tnl *t = netdev_priv(dev);
1411 	struct net *net = t->net;
1412 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1413 
1414 	switch (cmd) {
1415 	case SIOCGETTUNNEL:
1416 		if (dev == ip6n->fb_tnl_dev) {
1417 			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1418 				err = -EFAULT;
1419 				break;
1420 			}
1421 			ip6_tnl_parm_from_user(&p1, &p);
1422 			t = ip6_tnl_locate(net, &p1, 0);
1423 			if (t == NULL)
1424 				t = netdev_priv(dev);
1425 		} else {
1426 			memset(&p, 0, sizeof(p));
1427 		}
1428 		ip6_tnl_parm_to_user(&p, &t->parms);
1429 		if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) {
1430 			err = -EFAULT;
1431 		}
1432 		break;
1433 	case SIOCADDTUNNEL:
1434 	case SIOCCHGTUNNEL:
1435 		err = -EPERM;
1436 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1437 			break;
1438 		err = -EFAULT;
1439 		if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1440 			break;
1441 		err = -EINVAL;
1442 		if (p.proto != IPPROTO_IPV6 && p.proto != IPPROTO_IPIP &&
1443 		    p.proto != 0)
1444 			break;
1445 		ip6_tnl_parm_from_user(&p1, &p);
1446 		t = ip6_tnl_locate(net, &p1, cmd == SIOCADDTUNNEL);
1447 		if (cmd == SIOCCHGTUNNEL) {
1448 			if (t != NULL) {
1449 				if (t->dev != dev) {
1450 					err = -EEXIST;
1451 					break;
1452 				}
1453 			} else
1454 				t = netdev_priv(dev);
1455 			if (dev == ip6n->fb_tnl_dev)
1456 				err = ip6_tnl0_update(t, &p1);
1457 			else
1458 				err = ip6_tnl_update(t, &p1);
1459 		}
1460 		if (t) {
1461 			err = 0;
1462 			ip6_tnl_parm_to_user(&p, &t->parms);
1463 			if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1464 				err = -EFAULT;
1465 
1466 		} else
1467 			err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1468 		break;
1469 	case SIOCDELTUNNEL:
1470 		err = -EPERM;
1471 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1472 			break;
1473 
1474 		if (dev == ip6n->fb_tnl_dev) {
1475 			err = -EFAULT;
1476 			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1477 				break;
1478 			err = -ENOENT;
1479 			ip6_tnl_parm_from_user(&p1, &p);
1480 			t = ip6_tnl_locate(net, &p1, 0);
1481 			if (t == NULL)
1482 				break;
1483 			err = -EPERM;
1484 			if (t->dev == ip6n->fb_tnl_dev)
1485 				break;
1486 			dev = t->dev;
1487 		}
1488 		err = 0;
1489 		unregister_netdevice(dev);
1490 		break;
1491 	default:
1492 		err = -EINVAL;
1493 	}
1494 	return err;
1495 }
1496 
1497 /**
1498  * ip6_tnl_change_mtu - change mtu manually for tunnel device
1499  *   @dev: virtual device associated with tunnel
1500  *   @new_mtu: the new mtu
1501  *
1502  * Return:
1503  *   0 on success,
1504  *   %-EINVAL if mtu too small
1505  **/
1506 
1507 static int
1508 ip6_tnl_change_mtu(struct net_device *dev, int new_mtu)
1509 {
1510 	struct ip6_tnl *tnl = netdev_priv(dev);
1511 
1512 	if (tnl->parms.proto == IPPROTO_IPIP) {
1513 		if (new_mtu < 68)
1514 			return -EINVAL;
1515 	} else {
1516 		if (new_mtu < IPV6_MIN_MTU)
1517 			return -EINVAL;
1518 	}
1519 	if (new_mtu > 0xFFF8 - dev->hard_header_len)
1520 		return -EINVAL;
1521 	dev->mtu = new_mtu;
1522 	return 0;
1523 }
1524 
1525 
1526 static const struct net_device_ops ip6_tnl_netdev_ops = {
1527 	.ndo_init	= ip6_tnl_dev_init,
1528 	.ndo_uninit	= ip6_tnl_dev_uninit,
1529 	.ndo_start_xmit = ip6_tnl_xmit,
1530 	.ndo_do_ioctl	= ip6_tnl_ioctl,
1531 	.ndo_change_mtu = ip6_tnl_change_mtu,
1532 	.ndo_get_stats	= ip6_get_stats,
1533 };
1534 
1535 
1536 /**
1537  * ip6_tnl_dev_setup - setup virtual tunnel device
1538  *   @dev: virtual device associated with tunnel
1539  *
1540  * Description:
1541  *   Initialize function pointers and device parameters
1542  **/
1543 
1544 static void ip6_tnl_dev_setup(struct net_device *dev)
1545 {
1546 	struct ip6_tnl *t;
1547 
1548 	dev->netdev_ops = &ip6_tnl_netdev_ops;
1549 	dev->destructor = ip6_dev_free;
1550 
1551 	dev->type = ARPHRD_TUNNEL6;
1552 	dev->hard_header_len = LL_MAX_HEADER + sizeof(struct ipv6hdr);
1553 	dev->mtu = ETH_DATA_LEN - sizeof(struct ipv6hdr);
1554 	t = netdev_priv(dev);
1555 	if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1556 		dev->mtu -= 8;
1557 	dev->flags |= IFF_NOARP;
1558 	dev->addr_len = sizeof(struct in6_addr);
1559 	netif_keep_dst(dev);
1560 	/* This perm addr will be used as interface identifier by IPv6 */
1561 	dev->addr_assign_type = NET_ADDR_RANDOM;
1562 	eth_random_addr(dev->perm_addr);
1563 }
1564 
1565 
1566 /**
1567  * ip6_tnl_dev_init_gen - general initializer for all tunnel devices
1568  *   @dev: virtual device associated with tunnel
1569  **/
1570 
1571 static inline int
1572 ip6_tnl_dev_init_gen(struct net_device *dev)
1573 {
1574 	struct ip6_tnl *t = netdev_priv(dev);
1575 
1576 	t->dev = dev;
1577 	t->net = dev_net(dev);
1578 	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1579 	if (!dev->tstats)
1580 		return -ENOMEM;
1581 	return 0;
1582 }
1583 
1584 /**
1585  * ip6_tnl_dev_init - initializer for all non fallback tunnel devices
1586  *   @dev: virtual device associated with tunnel
1587  **/
1588 
1589 static int ip6_tnl_dev_init(struct net_device *dev)
1590 {
1591 	struct ip6_tnl *t = netdev_priv(dev);
1592 	int err = ip6_tnl_dev_init_gen(dev);
1593 
1594 	if (err)
1595 		return err;
1596 	ip6_tnl_link_config(t);
1597 	return 0;
1598 }
1599 
1600 /**
1601  * ip6_fb_tnl_dev_init - initializer for fallback tunnel device
1602  *   @dev: fallback device
1603  *
1604  * Return: 0
1605  **/
1606 
1607 static int __net_init ip6_fb_tnl_dev_init(struct net_device *dev)
1608 {
1609 	struct ip6_tnl *t = netdev_priv(dev);
1610 	struct net *net = dev_net(dev);
1611 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1612 
1613 	t->parms.proto = IPPROTO_IPV6;
1614 	dev_hold(dev);
1615 
1616 	rcu_assign_pointer(ip6n->tnls_wc[0], t);
1617 	return 0;
1618 }
1619 
1620 static int ip6_tnl_validate(struct nlattr *tb[], struct nlattr *data[])
1621 {
1622 	u8 proto;
1623 
1624 	if (!data || !data[IFLA_IPTUN_PROTO])
1625 		return 0;
1626 
1627 	proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1628 	if (proto != IPPROTO_IPV6 &&
1629 	    proto != IPPROTO_IPIP &&
1630 	    proto != 0)
1631 		return -EINVAL;
1632 
1633 	return 0;
1634 }
1635 
1636 static void ip6_tnl_netlink_parms(struct nlattr *data[],
1637 				  struct __ip6_tnl_parm *parms)
1638 {
1639 	memset(parms, 0, sizeof(*parms));
1640 
1641 	if (!data)
1642 		return;
1643 
1644 	if (data[IFLA_IPTUN_LINK])
1645 		parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
1646 
1647 	if (data[IFLA_IPTUN_LOCAL])
1648 		nla_memcpy(&parms->laddr, data[IFLA_IPTUN_LOCAL],
1649 			   sizeof(struct in6_addr));
1650 
1651 	if (data[IFLA_IPTUN_REMOTE])
1652 		nla_memcpy(&parms->raddr, data[IFLA_IPTUN_REMOTE],
1653 			   sizeof(struct in6_addr));
1654 
1655 	if (data[IFLA_IPTUN_TTL])
1656 		parms->hop_limit = nla_get_u8(data[IFLA_IPTUN_TTL]);
1657 
1658 	if (data[IFLA_IPTUN_ENCAP_LIMIT])
1659 		parms->encap_limit = nla_get_u8(data[IFLA_IPTUN_ENCAP_LIMIT]);
1660 
1661 	if (data[IFLA_IPTUN_FLOWINFO])
1662 		parms->flowinfo = nla_get_be32(data[IFLA_IPTUN_FLOWINFO]);
1663 
1664 	if (data[IFLA_IPTUN_FLAGS])
1665 		parms->flags = nla_get_u32(data[IFLA_IPTUN_FLAGS]);
1666 
1667 	if (data[IFLA_IPTUN_PROTO])
1668 		parms->proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1669 }
1670 
1671 static int ip6_tnl_newlink(struct net *src_net, struct net_device *dev,
1672 			   struct nlattr *tb[], struct nlattr *data[])
1673 {
1674 	struct net *net = dev_net(dev);
1675 	struct ip6_tnl *nt;
1676 
1677 	nt = netdev_priv(dev);
1678 	ip6_tnl_netlink_parms(data, &nt->parms);
1679 
1680 	if (ip6_tnl_locate(net, &nt->parms, 0))
1681 		return -EEXIST;
1682 
1683 	return ip6_tnl_create2(dev);
1684 }
1685 
1686 static int ip6_tnl_changelink(struct net_device *dev, struct nlattr *tb[],
1687 			      struct nlattr *data[])
1688 {
1689 	struct ip6_tnl *t = netdev_priv(dev);
1690 	struct __ip6_tnl_parm p;
1691 	struct net *net = t->net;
1692 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1693 
1694 	if (dev == ip6n->fb_tnl_dev)
1695 		return -EINVAL;
1696 
1697 	ip6_tnl_netlink_parms(data, &p);
1698 
1699 	t = ip6_tnl_locate(net, &p, 0);
1700 
1701 	if (t) {
1702 		if (t->dev != dev)
1703 			return -EEXIST;
1704 	} else
1705 		t = netdev_priv(dev);
1706 
1707 	return ip6_tnl_update(t, &p);
1708 }
1709 
1710 static void ip6_tnl_dellink(struct net_device *dev, struct list_head *head)
1711 {
1712 	struct net *net = dev_net(dev);
1713 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1714 
1715 	if (dev != ip6n->fb_tnl_dev)
1716 		unregister_netdevice_queue(dev, head);
1717 }
1718 
1719 static size_t ip6_tnl_get_size(const struct net_device *dev)
1720 {
1721 	return
1722 		/* IFLA_IPTUN_LINK */
1723 		nla_total_size(4) +
1724 		/* IFLA_IPTUN_LOCAL */
1725 		nla_total_size(sizeof(struct in6_addr)) +
1726 		/* IFLA_IPTUN_REMOTE */
1727 		nla_total_size(sizeof(struct in6_addr)) +
1728 		/* IFLA_IPTUN_TTL */
1729 		nla_total_size(1) +
1730 		/* IFLA_IPTUN_ENCAP_LIMIT */
1731 		nla_total_size(1) +
1732 		/* IFLA_IPTUN_FLOWINFO */
1733 		nla_total_size(4) +
1734 		/* IFLA_IPTUN_FLAGS */
1735 		nla_total_size(4) +
1736 		/* IFLA_IPTUN_PROTO */
1737 		nla_total_size(1) +
1738 		0;
1739 }
1740 
1741 static int ip6_tnl_fill_info(struct sk_buff *skb, const struct net_device *dev)
1742 {
1743 	struct ip6_tnl *tunnel = netdev_priv(dev);
1744 	struct __ip6_tnl_parm *parm = &tunnel->parms;
1745 
1746 	if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
1747 	    nla_put(skb, IFLA_IPTUN_LOCAL, sizeof(struct in6_addr),
1748 		    &parm->laddr) ||
1749 	    nla_put(skb, IFLA_IPTUN_REMOTE, sizeof(struct in6_addr),
1750 		    &parm->raddr) ||
1751 	    nla_put_u8(skb, IFLA_IPTUN_TTL, parm->hop_limit) ||
1752 	    nla_put_u8(skb, IFLA_IPTUN_ENCAP_LIMIT, parm->encap_limit) ||
1753 	    nla_put_be32(skb, IFLA_IPTUN_FLOWINFO, parm->flowinfo) ||
1754 	    nla_put_u32(skb, IFLA_IPTUN_FLAGS, parm->flags) ||
1755 	    nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->proto))
1756 		goto nla_put_failure;
1757 	return 0;
1758 
1759 nla_put_failure:
1760 	return -EMSGSIZE;
1761 }
1762 
1763 struct net *ip6_tnl_get_link_net(const struct net_device *dev)
1764 {
1765 	struct ip6_tnl *tunnel = netdev_priv(dev);
1766 
1767 	return tunnel->net;
1768 }
1769 EXPORT_SYMBOL(ip6_tnl_get_link_net);
1770 
1771 static const struct nla_policy ip6_tnl_policy[IFLA_IPTUN_MAX + 1] = {
1772 	[IFLA_IPTUN_LINK]		= { .type = NLA_U32 },
1773 	[IFLA_IPTUN_LOCAL]		= { .len = sizeof(struct in6_addr) },
1774 	[IFLA_IPTUN_REMOTE]		= { .len = sizeof(struct in6_addr) },
1775 	[IFLA_IPTUN_TTL]		= { .type = NLA_U8 },
1776 	[IFLA_IPTUN_ENCAP_LIMIT]	= { .type = NLA_U8 },
1777 	[IFLA_IPTUN_FLOWINFO]		= { .type = NLA_U32 },
1778 	[IFLA_IPTUN_FLAGS]		= { .type = NLA_U32 },
1779 	[IFLA_IPTUN_PROTO]		= { .type = NLA_U8 },
1780 };
1781 
1782 static struct rtnl_link_ops ip6_link_ops __read_mostly = {
1783 	.kind		= "ip6tnl",
1784 	.maxtype	= IFLA_IPTUN_MAX,
1785 	.policy		= ip6_tnl_policy,
1786 	.priv_size	= sizeof(struct ip6_tnl),
1787 	.setup		= ip6_tnl_dev_setup,
1788 	.validate	= ip6_tnl_validate,
1789 	.newlink	= ip6_tnl_newlink,
1790 	.changelink	= ip6_tnl_changelink,
1791 	.dellink	= ip6_tnl_dellink,
1792 	.get_size	= ip6_tnl_get_size,
1793 	.fill_info	= ip6_tnl_fill_info,
1794 	.get_link_net	= ip6_tnl_get_link_net,
1795 };
1796 
1797 static struct xfrm6_tunnel ip4ip6_handler __read_mostly = {
1798 	.handler	= ip4ip6_rcv,
1799 	.err_handler	= ip4ip6_err,
1800 	.priority	=	1,
1801 };
1802 
1803 static struct xfrm6_tunnel ip6ip6_handler __read_mostly = {
1804 	.handler	= ip6ip6_rcv,
1805 	.err_handler	= ip6ip6_err,
1806 	.priority	=	1,
1807 };
1808 
1809 static void __net_exit ip6_tnl_destroy_tunnels(struct net *net)
1810 {
1811 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1812 	struct net_device *dev, *aux;
1813 	int h;
1814 	struct ip6_tnl *t;
1815 	LIST_HEAD(list);
1816 
1817 	for_each_netdev_safe(net, dev, aux)
1818 		if (dev->rtnl_link_ops == &ip6_link_ops)
1819 			unregister_netdevice_queue(dev, &list);
1820 
1821 	for (h = 0; h < HASH_SIZE; h++) {
1822 		t = rtnl_dereference(ip6n->tnls_r_l[h]);
1823 		while (t != NULL) {
1824 			/* If dev is in the same netns, it has already
1825 			 * been added to the list by the previous loop.
1826 			 */
1827 			if (!net_eq(dev_net(t->dev), net))
1828 				unregister_netdevice_queue(t->dev, &list);
1829 			t = rtnl_dereference(t->next);
1830 		}
1831 	}
1832 
1833 	unregister_netdevice_many(&list);
1834 }
1835 
1836 static int __net_init ip6_tnl_init_net(struct net *net)
1837 {
1838 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1839 	struct ip6_tnl *t = NULL;
1840 	int err;
1841 
1842 	ip6n->tnls[0] = ip6n->tnls_wc;
1843 	ip6n->tnls[1] = ip6n->tnls_r_l;
1844 
1845 	err = -ENOMEM;
1846 	ip6n->fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6tnl0",
1847 					NET_NAME_UNKNOWN, ip6_tnl_dev_setup);
1848 
1849 	if (!ip6n->fb_tnl_dev)
1850 		goto err_alloc_dev;
1851 	dev_net_set(ip6n->fb_tnl_dev, net);
1852 	ip6n->fb_tnl_dev->rtnl_link_ops = &ip6_link_ops;
1853 	/* FB netdevice is special: we have one, and only one per netns.
1854 	 * Allowing to move it to another netns is clearly unsafe.
1855 	 */
1856 	ip6n->fb_tnl_dev->features |= NETIF_F_NETNS_LOCAL;
1857 
1858 	err = ip6_fb_tnl_dev_init(ip6n->fb_tnl_dev);
1859 	if (err < 0)
1860 		goto err_register;
1861 
1862 	err = register_netdev(ip6n->fb_tnl_dev);
1863 	if (err < 0)
1864 		goto err_register;
1865 
1866 	t = netdev_priv(ip6n->fb_tnl_dev);
1867 
1868 	strcpy(t->parms.name, ip6n->fb_tnl_dev->name);
1869 	return 0;
1870 
1871 err_register:
1872 	ip6_dev_free(ip6n->fb_tnl_dev);
1873 err_alloc_dev:
1874 	return err;
1875 }
1876 
1877 static void __net_exit ip6_tnl_exit_net(struct net *net)
1878 {
1879 	rtnl_lock();
1880 	ip6_tnl_destroy_tunnels(net);
1881 	rtnl_unlock();
1882 }
1883 
1884 static struct pernet_operations ip6_tnl_net_ops = {
1885 	.init = ip6_tnl_init_net,
1886 	.exit = ip6_tnl_exit_net,
1887 	.id   = &ip6_tnl_net_id,
1888 	.size = sizeof(struct ip6_tnl_net),
1889 };
1890 
1891 /**
1892  * ip6_tunnel_init - register protocol and reserve needed resources
1893  *
1894  * Return: 0 on success
1895  **/
1896 
1897 static int __init ip6_tunnel_init(void)
1898 {
1899 	int  err;
1900 
1901 	err = register_pernet_device(&ip6_tnl_net_ops);
1902 	if (err < 0)
1903 		goto out_pernet;
1904 
1905 	err = xfrm6_tunnel_register(&ip4ip6_handler, AF_INET);
1906 	if (err < 0) {
1907 		pr_err("%s: can't register ip4ip6\n", __func__);
1908 		goto out_ip4ip6;
1909 	}
1910 
1911 	err = xfrm6_tunnel_register(&ip6ip6_handler, AF_INET6);
1912 	if (err < 0) {
1913 		pr_err("%s: can't register ip6ip6\n", __func__);
1914 		goto out_ip6ip6;
1915 	}
1916 	err = rtnl_link_register(&ip6_link_ops);
1917 	if (err < 0)
1918 		goto rtnl_link_failed;
1919 
1920 	return 0;
1921 
1922 rtnl_link_failed:
1923 	xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6);
1924 out_ip6ip6:
1925 	xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET);
1926 out_ip4ip6:
1927 	unregister_pernet_device(&ip6_tnl_net_ops);
1928 out_pernet:
1929 	return err;
1930 }
1931 
1932 /**
1933  * ip6_tunnel_cleanup - free resources and unregister protocol
1934  **/
1935 
1936 static void __exit ip6_tunnel_cleanup(void)
1937 {
1938 	rtnl_link_unregister(&ip6_link_ops);
1939 	if (xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET))
1940 		pr_info("%s: can't deregister ip4ip6\n", __func__);
1941 
1942 	if (xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6))
1943 		pr_info("%s: can't deregister ip6ip6\n", __func__);
1944 
1945 	unregister_pernet_device(&ip6_tnl_net_ops);
1946 }
1947 
1948 module_init(ip6_tunnel_init);
1949 module_exit(ip6_tunnel_cleanup);
1950