xref: /openbmc/linux/net/ipv6/ip6_tunnel.c (revision f7d84fa7)
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 <linux/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 #include <net/dst_metadata.h>
61 
62 MODULE_AUTHOR("Ville Nuorvala");
63 MODULE_DESCRIPTION("IPv6 tunneling device");
64 MODULE_LICENSE("GPL");
65 MODULE_ALIAS_RTNL_LINK("ip6tnl");
66 MODULE_ALIAS_NETDEV("ip6tnl0");
67 
68 #define IP6_TUNNEL_HASH_SIZE_SHIFT  5
69 #define IP6_TUNNEL_HASH_SIZE (1 << IP6_TUNNEL_HASH_SIZE_SHIFT)
70 
71 static bool log_ecn_error = true;
72 module_param(log_ecn_error, bool, 0644);
73 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
74 
75 static u32 HASH(const struct in6_addr *addr1, const struct in6_addr *addr2)
76 {
77 	u32 hash = ipv6_addr_hash(addr1) ^ ipv6_addr_hash(addr2);
78 
79 	return hash_32(hash, IP6_TUNNEL_HASH_SIZE_SHIFT);
80 }
81 
82 static int ip6_tnl_dev_init(struct net_device *dev);
83 static void ip6_tnl_dev_setup(struct net_device *dev);
84 static struct rtnl_link_ops ip6_link_ops __read_mostly;
85 
86 static unsigned int ip6_tnl_net_id __read_mostly;
87 struct ip6_tnl_net {
88 	/* the IPv6 tunnel fallback device */
89 	struct net_device *fb_tnl_dev;
90 	/* lists for storing tunnels in use */
91 	struct ip6_tnl __rcu *tnls_r_l[IP6_TUNNEL_HASH_SIZE];
92 	struct ip6_tnl __rcu *tnls_wc[1];
93 	struct ip6_tnl __rcu **tnls[2];
94 	struct ip6_tnl __rcu *collect_md_tun;
95 };
96 
97 static struct net_device_stats *ip6_get_stats(struct net_device *dev)
98 {
99 	struct pcpu_sw_netstats tmp, sum = { 0 };
100 	int i;
101 
102 	for_each_possible_cpu(i) {
103 		unsigned int start;
104 		const struct pcpu_sw_netstats *tstats =
105 						   per_cpu_ptr(dev->tstats, i);
106 
107 		do {
108 			start = u64_stats_fetch_begin_irq(&tstats->syncp);
109 			tmp.rx_packets = tstats->rx_packets;
110 			tmp.rx_bytes = tstats->rx_bytes;
111 			tmp.tx_packets = tstats->tx_packets;
112 			tmp.tx_bytes =  tstats->tx_bytes;
113 		} while (u64_stats_fetch_retry_irq(&tstats->syncp, start));
114 
115 		sum.rx_packets += tmp.rx_packets;
116 		sum.rx_bytes   += tmp.rx_bytes;
117 		sum.tx_packets += tmp.tx_packets;
118 		sum.tx_bytes   += tmp.tx_bytes;
119 	}
120 	dev->stats.rx_packets = sum.rx_packets;
121 	dev->stats.rx_bytes   = sum.rx_bytes;
122 	dev->stats.tx_packets = sum.tx_packets;
123 	dev->stats.tx_bytes   = sum.tx_bytes;
124 	return &dev->stats;
125 }
126 
127 /**
128  * ip6_tnl_lookup - fetch tunnel matching the end-point addresses
129  *   @remote: the address of the tunnel exit-point
130  *   @local: the address of the tunnel entry-point
131  *
132  * Return:
133  *   tunnel matching given end-points if found,
134  *   else fallback tunnel if its device is up,
135  *   else %NULL
136  **/
137 
138 #define for_each_ip6_tunnel_rcu(start) \
139 	for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
140 
141 static struct ip6_tnl *
142 ip6_tnl_lookup(struct net *net, const struct in6_addr *remote, const struct in6_addr *local)
143 {
144 	unsigned int hash = HASH(remote, local);
145 	struct ip6_tnl *t;
146 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
147 	struct in6_addr any;
148 
149 	for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
150 		if (ipv6_addr_equal(local, &t->parms.laddr) &&
151 		    ipv6_addr_equal(remote, &t->parms.raddr) &&
152 		    (t->dev->flags & IFF_UP))
153 			return t;
154 	}
155 
156 	memset(&any, 0, sizeof(any));
157 	hash = HASH(&any, local);
158 	for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
159 		if (ipv6_addr_equal(local, &t->parms.laddr) &&
160 		    ipv6_addr_any(&t->parms.raddr) &&
161 		    (t->dev->flags & IFF_UP))
162 			return t;
163 	}
164 
165 	hash = HASH(remote, &any);
166 	for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
167 		if (ipv6_addr_equal(remote, &t->parms.raddr) &&
168 		    ipv6_addr_any(&t->parms.laddr) &&
169 		    (t->dev->flags & IFF_UP))
170 			return t;
171 	}
172 
173 	t = rcu_dereference(ip6n->collect_md_tun);
174 	if (t)
175 		return t;
176 
177 	t = rcu_dereference(ip6n->tnls_wc[0]);
178 	if (t && (t->dev->flags & IFF_UP))
179 		return t;
180 
181 	return NULL;
182 }
183 
184 /**
185  * ip6_tnl_bucket - get head of list matching given tunnel parameters
186  *   @p: parameters containing tunnel end-points
187  *
188  * Description:
189  *   ip6_tnl_bucket() returns the head of the list matching the
190  *   &struct in6_addr entries laddr and raddr in @p.
191  *
192  * Return: head of IPv6 tunnel list
193  **/
194 
195 static struct ip6_tnl __rcu **
196 ip6_tnl_bucket(struct ip6_tnl_net *ip6n, const struct __ip6_tnl_parm *p)
197 {
198 	const struct in6_addr *remote = &p->raddr;
199 	const struct in6_addr *local = &p->laddr;
200 	unsigned int h = 0;
201 	int prio = 0;
202 
203 	if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) {
204 		prio = 1;
205 		h = HASH(remote, local);
206 	}
207 	return &ip6n->tnls[prio][h];
208 }
209 
210 /**
211  * ip6_tnl_link - add tunnel to hash table
212  *   @t: tunnel to be added
213  **/
214 
215 static void
216 ip6_tnl_link(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
217 {
218 	struct ip6_tnl __rcu **tp = ip6_tnl_bucket(ip6n, &t->parms);
219 
220 	if (t->parms.collect_md)
221 		rcu_assign_pointer(ip6n->collect_md_tun, t);
222 	rcu_assign_pointer(t->next , rtnl_dereference(*tp));
223 	rcu_assign_pointer(*tp, t);
224 }
225 
226 /**
227  * ip6_tnl_unlink - remove tunnel from hash table
228  *   @t: tunnel to be removed
229  **/
230 
231 static void
232 ip6_tnl_unlink(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
233 {
234 	struct ip6_tnl __rcu **tp;
235 	struct ip6_tnl *iter;
236 
237 	if (t->parms.collect_md)
238 		rcu_assign_pointer(ip6n->collect_md_tun, NULL);
239 
240 	for (tp = ip6_tnl_bucket(ip6n, &t->parms);
241 	     (iter = rtnl_dereference(*tp)) != NULL;
242 	     tp = &iter->next) {
243 		if (t == iter) {
244 			rcu_assign_pointer(*tp, t->next);
245 			break;
246 		}
247 	}
248 }
249 
250 static void ip6_dev_free(struct net_device *dev)
251 {
252 	struct ip6_tnl *t = netdev_priv(dev);
253 
254 	gro_cells_destroy(&t->gro_cells);
255 	dst_cache_destroy(&t->dst_cache);
256 	free_percpu(dev->tstats);
257 }
258 
259 static int ip6_tnl_create2(struct net_device *dev)
260 {
261 	struct ip6_tnl *t = netdev_priv(dev);
262 	struct net *net = dev_net(dev);
263 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
264 	int err;
265 
266 	t = netdev_priv(dev);
267 
268 	dev->rtnl_link_ops = &ip6_link_ops;
269 	err = register_netdevice(dev);
270 	if (err < 0)
271 		goto out;
272 
273 	strcpy(t->parms.name, dev->name);
274 
275 	dev_hold(dev);
276 	ip6_tnl_link(ip6n, t);
277 	return 0;
278 
279 out:
280 	return err;
281 }
282 
283 /**
284  * ip6_tnl_create - create a new tunnel
285  *   @p: tunnel parameters
286  *   @pt: pointer to new tunnel
287  *
288  * Description:
289  *   Create tunnel matching given parameters.
290  *
291  * Return:
292  *   created tunnel or error pointer
293  **/
294 
295 static struct ip6_tnl *ip6_tnl_create(struct net *net, struct __ip6_tnl_parm *p)
296 {
297 	struct net_device *dev;
298 	struct ip6_tnl *t;
299 	char name[IFNAMSIZ];
300 	int err = -ENOMEM;
301 
302 	if (p->name[0])
303 		strlcpy(name, p->name, IFNAMSIZ);
304 	else
305 		sprintf(name, "ip6tnl%%d");
306 
307 	dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
308 			   ip6_tnl_dev_setup);
309 	if (!dev)
310 		goto failed;
311 
312 	dev_net_set(dev, net);
313 
314 	t = netdev_priv(dev);
315 	t->parms = *p;
316 	t->net = dev_net(dev);
317 	err = ip6_tnl_create2(dev);
318 	if (err < 0)
319 		goto failed_free;
320 
321 	return t;
322 
323 failed_free:
324 	free_netdev(dev);
325 failed:
326 	return ERR_PTR(err);
327 }
328 
329 /**
330  * ip6_tnl_locate - find or create tunnel matching given parameters
331  *   @p: tunnel parameters
332  *   @create: != 0 if allowed to create new tunnel if no match found
333  *
334  * Description:
335  *   ip6_tnl_locate() first tries to locate an existing tunnel
336  *   based on @parms. If this is unsuccessful, but @create is set a new
337  *   tunnel device is created and registered for use.
338  *
339  * Return:
340  *   matching tunnel or error pointer
341  **/
342 
343 static struct ip6_tnl *ip6_tnl_locate(struct net *net,
344 		struct __ip6_tnl_parm *p, int create)
345 {
346 	const struct in6_addr *remote = &p->raddr;
347 	const struct in6_addr *local = &p->laddr;
348 	struct ip6_tnl __rcu **tp;
349 	struct ip6_tnl *t;
350 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
351 
352 	for (tp = ip6_tnl_bucket(ip6n, p);
353 	     (t = rtnl_dereference(*tp)) != NULL;
354 	     tp = &t->next) {
355 		if (ipv6_addr_equal(local, &t->parms.laddr) &&
356 		    ipv6_addr_equal(remote, &t->parms.raddr)) {
357 			if (create)
358 				return ERR_PTR(-EEXIST);
359 
360 			return t;
361 		}
362 	}
363 	if (!create)
364 		return ERR_PTR(-ENODEV);
365 	return ip6_tnl_create(net, p);
366 }
367 
368 /**
369  * ip6_tnl_dev_uninit - tunnel device uninitializer
370  *   @dev: the device to be destroyed
371  *
372  * Description:
373  *   ip6_tnl_dev_uninit() removes tunnel from its list
374  **/
375 
376 static void
377 ip6_tnl_dev_uninit(struct net_device *dev)
378 {
379 	struct ip6_tnl *t = netdev_priv(dev);
380 	struct net *net = t->net;
381 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
382 
383 	if (dev == ip6n->fb_tnl_dev)
384 		RCU_INIT_POINTER(ip6n->tnls_wc[0], NULL);
385 	else
386 		ip6_tnl_unlink(ip6n, t);
387 	dst_cache_reset(&t->dst_cache);
388 	dev_put(dev);
389 }
390 
391 /**
392  * parse_tvl_tnl_enc_lim - handle encapsulation limit option
393  *   @skb: received socket buffer
394  *
395  * Return:
396  *   0 if none was found,
397  *   else index to encapsulation limit
398  **/
399 
400 __u16 ip6_tnl_parse_tlv_enc_lim(struct sk_buff *skb, __u8 *raw)
401 {
402 	const struct ipv6hdr *ipv6h = (const struct ipv6hdr *)raw;
403 	unsigned int nhoff = raw - skb->data;
404 	unsigned int off = nhoff + sizeof(*ipv6h);
405 	u8 next, nexthdr = ipv6h->nexthdr;
406 
407 	while (ipv6_ext_hdr(nexthdr) && nexthdr != NEXTHDR_NONE) {
408 		struct ipv6_opt_hdr *hdr;
409 		u16 optlen;
410 
411 		if (!pskb_may_pull(skb, off + sizeof(*hdr)))
412 			break;
413 
414 		hdr = (struct ipv6_opt_hdr *)(skb->data + off);
415 		if (nexthdr == NEXTHDR_FRAGMENT) {
416 			struct frag_hdr *frag_hdr = (struct frag_hdr *) hdr;
417 			if (frag_hdr->frag_off)
418 				break;
419 			optlen = 8;
420 		} else if (nexthdr == NEXTHDR_AUTH) {
421 			optlen = (hdr->hdrlen + 2) << 2;
422 		} else {
423 			optlen = ipv6_optlen(hdr);
424 		}
425 		/* cache hdr->nexthdr, since pskb_may_pull() might
426 		 * invalidate hdr
427 		 */
428 		next = hdr->nexthdr;
429 		if (nexthdr == NEXTHDR_DEST) {
430 			u16 i = 2;
431 
432 			/* Remember : hdr is no longer valid at this point. */
433 			if (!pskb_may_pull(skb, off + optlen))
434 				break;
435 
436 			while (1) {
437 				struct ipv6_tlv_tnl_enc_lim *tel;
438 
439 				/* No more room for encapsulation limit */
440 				if (i + sizeof(*tel) > optlen)
441 					break;
442 
443 				tel = (struct ipv6_tlv_tnl_enc_lim *)(skb->data + off + i);
444 				/* return index of option if found and valid */
445 				if (tel->type == IPV6_TLV_TNL_ENCAP_LIMIT &&
446 				    tel->length == 1)
447 					return i + off - nhoff;
448 				/* else jump to next option */
449 				if (tel->type)
450 					i += tel->length + 2;
451 				else
452 					i++;
453 			}
454 		}
455 		nexthdr = next;
456 		off += optlen;
457 	}
458 	return 0;
459 }
460 EXPORT_SYMBOL(ip6_tnl_parse_tlv_enc_lim);
461 
462 /**
463  * ip6_tnl_err - tunnel error handler
464  *
465  * Description:
466  *   ip6_tnl_err() should handle errors in the tunnel according
467  *   to the specifications in RFC 2473.
468  **/
469 
470 static int
471 ip6_tnl_err(struct sk_buff *skb, __u8 ipproto, struct inet6_skb_parm *opt,
472 	    u8 *type, u8 *code, int *msg, __u32 *info, int offset)
473 {
474 	const struct ipv6hdr *ipv6h = (const struct ipv6hdr *) skb->data;
475 	struct ip6_tnl *t;
476 	int rel_msg = 0;
477 	u8 rel_type = ICMPV6_DEST_UNREACH;
478 	u8 rel_code = ICMPV6_ADDR_UNREACH;
479 	u8 tproto;
480 	__u32 rel_info = 0;
481 	__u16 len;
482 	int err = -ENOENT;
483 
484 	/* If the packet doesn't contain the original IPv6 header we are
485 	   in trouble since we might need the source address for further
486 	   processing of the error. */
487 
488 	rcu_read_lock();
489 	t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->daddr, &ipv6h->saddr);
490 	if (!t)
491 		goto out;
492 
493 	tproto = ACCESS_ONCE(t->parms.proto);
494 	if (tproto != ipproto && tproto != 0)
495 		goto out;
496 
497 	err = 0;
498 
499 	switch (*type) {
500 		__u32 teli;
501 		struct ipv6_tlv_tnl_enc_lim *tel;
502 		__u32 mtu;
503 	case ICMPV6_DEST_UNREACH:
504 		net_dbg_ratelimited("%s: Path to destination invalid or inactive!\n",
505 				    t->parms.name);
506 		rel_msg = 1;
507 		break;
508 	case ICMPV6_TIME_EXCEED:
509 		if ((*code) == ICMPV6_EXC_HOPLIMIT) {
510 			net_dbg_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
511 					    t->parms.name);
512 			rel_msg = 1;
513 		}
514 		break;
515 	case ICMPV6_PARAMPROB:
516 		teli = 0;
517 		if ((*code) == ICMPV6_HDR_FIELD)
518 			teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
519 
520 		if (teli && teli == *info - 2) {
521 			tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
522 			if (tel->encap_limit == 0) {
523 				net_dbg_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
524 						    t->parms.name);
525 				rel_msg = 1;
526 			}
527 		} else {
528 			net_dbg_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
529 					    t->parms.name);
530 		}
531 		break;
532 	case ICMPV6_PKT_TOOBIG:
533 		mtu = *info - offset;
534 		if (mtu < IPV6_MIN_MTU)
535 			mtu = IPV6_MIN_MTU;
536 		t->dev->mtu = mtu;
537 
538 		len = sizeof(*ipv6h) + ntohs(ipv6h->payload_len);
539 		if (len > mtu) {
540 			rel_type = ICMPV6_PKT_TOOBIG;
541 			rel_code = 0;
542 			rel_info = mtu;
543 			rel_msg = 1;
544 		}
545 		break;
546 	}
547 
548 	*type = rel_type;
549 	*code = rel_code;
550 	*info = rel_info;
551 	*msg = rel_msg;
552 
553 out:
554 	rcu_read_unlock();
555 	return err;
556 }
557 
558 static int
559 ip4ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
560 	   u8 type, u8 code, int offset, __be32 info)
561 {
562 	int rel_msg = 0;
563 	u8 rel_type = type;
564 	u8 rel_code = code;
565 	__u32 rel_info = ntohl(info);
566 	int err;
567 	struct sk_buff *skb2;
568 	const struct iphdr *eiph;
569 	struct rtable *rt;
570 	struct flowi4 fl4;
571 
572 	err = ip6_tnl_err(skb, IPPROTO_IPIP, opt, &rel_type, &rel_code,
573 			  &rel_msg, &rel_info, offset);
574 	if (err < 0)
575 		return err;
576 
577 	if (rel_msg == 0)
578 		return 0;
579 
580 	switch (rel_type) {
581 	case ICMPV6_DEST_UNREACH:
582 		if (rel_code != ICMPV6_ADDR_UNREACH)
583 			return 0;
584 		rel_type = ICMP_DEST_UNREACH;
585 		rel_code = ICMP_HOST_UNREACH;
586 		break;
587 	case ICMPV6_PKT_TOOBIG:
588 		if (rel_code != 0)
589 			return 0;
590 		rel_type = ICMP_DEST_UNREACH;
591 		rel_code = ICMP_FRAG_NEEDED;
592 		break;
593 	case NDISC_REDIRECT:
594 		rel_type = ICMP_REDIRECT;
595 		rel_code = ICMP_REDIR_HOST;
596 	default:
597 		return 0;
598 	}
599 
600 	if (!pskb_may_pull(skb, offset + sizeof(struct iphdr)))
601 		return 0;
602 
603 	skb2 = skb_clone(skb, GFP_ATOMIC);
604 	if (!skb2)
605 		return 0;
606 
607 	skb_dst_drop(skb2);
608 
609 	skb_pull(skb2, offset);
610 	skb_reset_network_header(skb2);
611 	eiph = ip_hdr(skb2);
612 
613 	/* Try to guess incoming interface */
614 	rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL,
615 				   eiph->saddr, 0,
616 				   0, 0,
617 				   IPPROTO_IPIP, RT_TOS(eiph->tos), 0);
618 	if (IS_ERR(rt))
619 		goto out;
620 
621 	skb2->dev = rt->dst.dev;
622 
623 	/* route "incoming" packet */
624 	if (rt->rt_flags & RTCF_LOCAL) {
625 		ip_rt_put(rt);
626 		rt = NULL;
627 		rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL,
628 					   eiph->daddr, eiph->saddr,
629 					   0, 0,
630 					   IPPROTO_IPIP,
631 					   RT_TOS(eiph->tos), 0);
632 		if (IS_ERR(rt) ||
633 		    rt->dst.dev->type != ARPHRD_TUNNEL) {
634 			if (!IS_ERR(rt))
635 				ip_rt_put(rt);
636 			goto out;
637 		}
638 		skb_dst_set(skb2, &rt->dst);
639 	} else {
640 		ip_rt_put(rt);
641 		if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos,
642 				   skb2->dev) ||
643 		    skb_dst(skb2)->dev->type != ARPHRD_TUNNEL)
644 			goto out;
645 	}
646 
647 	/* change mtu on this route */
648 	if (rel_type == ICMP_DEST_UNREACH && rel_code == ICMP_FRAG_NEEDED) {
649 		if (rel_info > dst_mtu(skb_dst(skb2)))
650 			goto out;
651 
652 		skb_dst(skb2)->ops->update_pmtu(skb_dst(skb2), NULL, skb2, rel_info);
653 	}
654 	if (rel_type == ICMP_REDIRECT)
655 		skb_dst(skb2)->ops->redirect(skb_dst(skb2), NULL, skb2);
656 
657 	icmp_send(skb2, rel_type, rel_code, htonl(rel_info));
658 
659 out:
660 	kfree_skb(skb2);
661 	return 0;
662 }
663 
664 static int
665 ip6ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
666 	   u8 type, u8 code, int offset, __be32 info)
667 {
668 	int rel_msg = 0;
669 	u8 rel_type = type;
670 	u8 rel_code = code;
671 	__u32 rel_info = ntohl(info);
672 	int err;
673 
674 	err = ip6_tnl_err(skb, IPPROTO_IPV6, opt, &rel_type, &rel_code,
675 			  &rel_msg, &rel_info, offset);
676 	if (err < 0)
677 		return err;
678 
679 	if (rel_msg && pskb_may_pull(skb, offset + sizeof(struct ipv6hdr))) {
680 		struct rt6_info *rt;
681 		struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
682 
683 		if (!skb2)
684 			return 0;
685 
686 		skb_dst_drop(skb2);
687 		skb_pull(skb2, offset);
688 		skb_reset_network_header(skb2);
689 
690 		/* Try to guess incoming interface */
691 		rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr,
692 				NULL, 0, 0);
693 
694 		if (rt && rt->dst.dev)
695 			skb2->dev = rt->dst.dev;
696 
697 		icmpv6_send(skb2, rel_type, rel_code, rel_info);
698 
699 		ip6_rt_put(rt);
700 
701 		kfree_skb(skb2);
702 	}
703 
704 	return 0;
705 }
706 
707 static int ip4ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
708 				       const struct ipv6hdr *ipv6h,
709 				       struct sk_buff *skb)
710 {
711 	__u8 dsfield = ipv6_get_dsfield(ipv6h) & ~INET_ECN_MASK;
712 
713 	if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
714 		ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, dsfield);
715 
716 	return IP6_ECN_decapsulate(ipv6h, skb);
717 }
718 
719 static int ip6ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
720 				       const struct ipv6hdr *ipv6h,
721 				       struct sk_buff *skb)
722 {
723 	if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
724 		ipv6_copy_dscp(ipv6_get_dsfield(ipv6h), ipv6_hdr(skb));
725 
726 	return IP6_ECN_decapsulate(ipv6h, skb);
727 }
728 
729 __u32 ip6_tnl_get_cap(struct ip6_tnl *t,
730 			     const struct in6_addr *laddr,
731 			     const struct in6_addr *raddr)
732 {
733 	struct __ip6_tnl_parm *p = &t->parms;
734 	int ltype = ipv6_addr_type(laddr);
735 	int rtype = ipv6_addr_type(raddr);
736 	__u32 flags = 0;
737 
738 	if (ltype == IPV6_ADDR_ANY || rtype == IPV6_ADDR_ANY) {
739 		flags = IP6_TNL_F_CAP_PER_PACKET;
740 	} else if (ltype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
741 		   rtype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
742 		   !((ltype|rtype) & IPV6_ADDR_LOOPBACK) &&
743 		   (!((ltype|rtype) & IPV6_ADDR_LINKLOCAL) || p->link)) {
744 		if (ltype&IPV6_ADDR_UNICAST)
745 			flags |= IP6_TNL_F_CAP_XMIT;
746 		if (rtype&IPV6_ADDR_UNICAST)
747 			flags |= IP6_TNL_F_CAP_RCV;
748 	}
749 	return flags;
750 }
751 EXPORT_SYMBOL(ip6_tnl_get_cap);
752 
753 /* called with rcu_read_lock() */
754 int ip6_tnl_rcv_ctl(struct ip6_tnl *t,
755 				  const struct in6_addr *laddr,
756 				  const struct in6_addr *raddr)
757 {
758 	struct __ip6_tnl_parm *p = &t->parms;
759 	int ret = 0;
760 	struct net *net = t->net;
761 
762 	if ((p->flags & IP6_TNL_F_CAP_RCV) ||
763 	    ((p->flags & IP6_TNL_F_CAP_PER_PACKET) &&
764 	     (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_RCV))) {
765 		struct net_device *ldev = NULL;
766 
767 		if (p->link)
768 			ldev = dev_get_by_index_rcu(net, p->link);
769 
770 		if ((ipv6_addr_is_multicast(laddr) ||
771 		     likely(ipv6_chk_addr(net, laddr, ldev, 0))) &&
772 		    likely(!ipv6_chk_addr(net, raddr, NULL, 0)))
773 			ret = 1;
774 	}
775 	return ret;
776 }
777 EXPORT_SYMBOL_GPL(ip6_tnl_rcv_ctl);
778 
779 static int __ip6_tnl_rcv(struct ip6_tnl *tunnel, struct sk_buff *skb,
780 			 const struct tnl_ptk_info *tpi,
781 			 struct metadata_dst *tun_dst,
782 			 int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
783 						const struct ipv6hdr *ipv6h,
784 						struct sk_buff *skb),
785 			 bool log_ecn_err)
786 {
787 	struct pcpu_sw_netstats *tstats;
788 	const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
789 	int err;
790 
791 	if ((!(tpi->flags & TUNNEL_CSUM) &&
792 	     (tunnel->parms.i_flags & TUNNEL_CSUM)) ||
793 	    ((tpi->flags & TUNNEL_CSUM) &&
794 	     !(tunnel->parms.i_flags & TUNNEL_CSUM))) {
795 		tunnel->dev->stats.rx_crc_errors++;
796 		tunnel->dev->stats.rx_errors++;
797 		goto drop;
798 	}
799 
800 	if (tunnel->parms.i_flags & TUNNEL_SEQ) {
801 		if (!(tpi->flags & TUNNEL_SEQ) ||
802 		    (tunnel->i_seqno &&
803 		     (s32)(ntohl(tpi->seq) - tunnel->i_seqno) < 0)) {
804 			tunnel->dev->stats.rx_fifo_errors++;
805 			tunnel->dev->stats.rx_errors++;
806 			goto drop;
807 		}
808 		tunnel->i_seqno = ntohl(tpi->seq) + 1;
809 	}
810 
811 	skb->protocol = tpi->proto;
812 
813 	/* Warning: All skb pointers will be invalidated! */
814 	if (tunnel->dev->type == ARPHRD_ETHER) {
815 		if (!pskb_may_pull(skb, ETH_HLEN)) {
816 			tunnel->dev->stats.rx_length_errors++;
817 			tunnel->dev->stats.rx_errors++;
818 			goto drop;
819 		}
820 
821 		ipv6h = ipv6_hdr(skb);
822 		skb->protocol = eth_type_trans(skb, tunnel->dev);
823 		skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
824 	} else {
825 		skb->dev = tunnel->dev;
826 	}
827 
828 	skb_reset_network_header(skb);
829 	memset(skb->cb, 0, sizeof(struct inet6_skb_parm));
830 
831 	__skb_tunnel_rx(skb, tunnel->dev, tunnel->net);
832 
833 	err = dscp_ecn_decapsulate(tunnel, ipv6h, skb);
834 	if (unlikely(err)) {
835 		if (log_ecn_err)
836 			net_info_ratelimited("non-ECT from %pI6 with DS=%#x\n",
837 					     &ipv6h->saddr,
838 					     ipv6_get_dsfield(ipv6h));
839 		if (err > 1) {
840 			++tunnel->dev->stats.rx_frame_errors;
841 			++tunnel->dev->stats.rx_errors;
842 			goto drop;
843 		}
844 	}
845 
846 	tstats = this_cpu_ptr(tunnel->dev->tstats);
847 	u64_stats_update_begin(&tstats->syncp);
848 	tstats->rx_packets++;
849 	tstats->rx_bytes += skb->len;
850 	u64_stats_update_end(&tstats->syncp);
851 
852 	skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(tunnel->dev)));
853 
854 	if (tun_dst)
855 		skb_dst_set(skb, (struct dst_entry *)tun_dst);
856 
857 	gro_cells_receive(&tunnel->gro_cells, skb);
858 	return 0;
859 
860 drop:
861 	kfree_skb(skb);
862 	return 0;
863 }
864 
865 int ip6_tnl_rcv(struct ip6_tnl *t, struct sk_buff *skb,
866 		const struct tnl_ptk_info *tpi,
867 		struct metadata_dst *tun_dst,
868 		bool log_ecn_err)
869 {
870 	return __ip6_tnl_rcv(t, skb, tpi, NULL, ip6ip6_dscp_ecn_decapsulate,
871 			     log_ecn_err);
872 }
873 EXPORT_SYMBOL(ip6_tnl_rcv);
874 
875 static const struct tnl_ptk_info tpi_v6 = {
876 	/* no tunnel info required for ipxip6. */
877 	.proto = htons(ETH_P_IPV6),
878 };
879 
880 static const struct tnl_ptk_info tpi_v4 = {
881 	/* no tunnel info required for ipxip6. */
882 	.proto = htons(ETH_P_IP),
883 };
884 
885 static int ipxip6_rcv(struct sk_buff *skb, u8 ipproto,
886 		      const struct tnl_ptk_info *tpi,
887 		      int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
888 						  const struct ipv6hdr *ipv6h,
889 						  struct sk_buff *skb))
890 {
891 	struct ip6_tnl *t;
892 	const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
893 	struct metadata_dst *tun_dst = NULL;
894 	int ret = -1;
895 
896 	rcu_read_lock();
897 	t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->saddr, &ipv6h->daddr);
898 
899 	if (t) {
900 		u8 tproto = ACCESS_ONCE(t->parms.proto);
901 
902 		if (tproto != ipproto && tproto != 0)
903 			goto drop;
904 		if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
905 			goto drop;
906 		if (!ip6_tnl_rcv_ctl(t, &ipv6h->daddr, &ipv6h->saddr))
907 			goto drop;
908 		if (iptunnel_pull_header(skb, 0, tpi->proto, false))
909 			goto drop;
910 		if (t->parms.collect_md) {
911 			tun_dst = ipv6_tun_rx_dst(skb, 0, 0, 0);
912 			if (!tun_dst)
913 				return 0;
914 		}
915 		ret = __ip6_tnl_rcv(t, skb, tpi, tun_dst, dscp_ecn_decapsulate,
916 				    log_ecn_error);
917 	}
918 
919 	rcu_read_unlock();
920 
921 	return ret;
922 
923 drop:
924 	rcu_read_unlock();
925 	kfree_skb(skb);
926 	return 0;
927 }
928 
929 static int ip4ip6_rcv(struct sk_buff *skb)
930 {
931 	return ipxip6_rcv(skb, IPPROTO_IPIP, &tpi_v4,
932 			  ip4ip6_dscp_ecn_decapsulate);
933 }
934 
935 static int ip6ip6_rcv(struct sk_buff *skb)
936 {
937 	return ipxip6_rcv(skb, IPPROTO_IPV6, &tpi_v6,
938 			  ip6ip6_dscp_ecn_decapsulate);
939 }
940 
941 struct ipv6_tel_txoption {
942 	struct ipv6_txoptions ops;
943 	__u8 dst_opt[8];
944 };
945 
946 static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit)
947 {
948 	memset(opt, 0, sizeof(struct ipv6_tel_txoption));
949 
950 	opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT;
951 	opt->dst_opt[3] = 1;
952 	opt->dst_opt[4] = encap_limit;
953 	opt->dst_opt[5] = IPV6_TLV_PADN;
954 	opt->dst_opt[6] = 1;
955 
956 	opt->ops.dst1opt = (struct ipv6_opt_hdr *) opt->dst_opt;
957 	opt->ops.opt_nflen = 8;
958 }
959 
960 /**
961  * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
962  *   @t: the outgoing tunnel device
963  *   @hdr: IPv6 header from the incoming packet
964  *
965  * Description:
966  *   Avoid trivial tunneling loop by checking that tunnel exit-point
967  *   doesn't match source of incoming packet.
968  *
969  * Return:
970  *   1 if conflict,
971  *   0 else
972  **/
973 
974 static inline bool
975 ip6_tnl_addr_conflict(const struct ip6_tnl *t, const struct ipv6hdr *hdr)
976 {
977 	return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
978 }
979 
980 int ip6_tnl_xmit_ctl(struct ip6_tnl *t,
981 		     const struct in6_addr *laddr,
982 		     const struct in6_addr *raddr)
983 {
984 	struct __ip6_tnl_parm *p = &t->parms;
985 	int ret = 0;
986 	struct net *net = t->net;
987 
988 	if ((p->flags & IP6_TNL_F_CAP_XMIT) ||
989 	    ((p->flags & IP6_TNL_F_CAP_PER_PACKET) &&
990 	     (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_XMIT))) {
991 		struct net_device *ldev = NULL;
992 
993 		rcu_read_lock();
994 		if (p->link)
995 			ldev = dev_get_by_index_rcu(net, p->link);
996 
997 		if (unlikely(!ipv6_chk_addr(net, laddr, ldev, 0)))
998 			pr_warn("%s xmit: Local address not yet configured!\n",
999 				p->name);
1000 		else if (!ipv6_addr_is_multicast(raddr) &&
1001 			 unlikely(ipv6_chk_addr(net, raddr, NULL, 0)))
1002 			pr_warn("%s xmit: Routing loop! Remote address found on this node!\n",
1003 				p->name);
1004 		else
1005 			ret = 1;
1006 		rcu_read_unlock();
1007 	}
1008 	return ret;
1009 }
1010 EXPORT_SYMBOL_GPL(ip6_tnl_xmit_ctl);
1011 
1012 /**
1013  * ip6_tnl_xmit - encapsulate packet and send
1014  *   @skb: the outgoing socket buffer
1015  *   @dev: the outgoing tunnel device
1016  *   @dsfield: dscp code for outer header
1017  *   @fl6: flow of tunneled packet
1018  *   @encap_limit: encapsulation limit
1019  *   @pmtu: Path MTU is stored if packet is too big
1020  *   @proto: next header value
1021  *
1022  * Description:
1023  *   Build new header and do some sanity checks on the packet before sending
1024  *   it.
1025  *
1026  * Return:
1027  *   0 on success
1028  *   -1 fail
1029  *   %-EMSGSIZE message too big. return mtu in this case.
1030  **/
1031 
1032 int ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev, __u8 dsfield,
1033 		 struct flowi6 *fl6, int encap_limit, __u32 *pmtu,
1034 		 __u8 proto)
1035 {
1036 	struct ip6_tnl *t = netdev_priv(dev);
1037 	struct net *net = t->net;
1038 	struct net_device_stats *stats = &t->dev->stats;
1039 	struct ipv6hdr *ipv6h;
1040 	struct ipv6_tel_txoption opt;
1041 	struct dst_entry *dst = NULL, *ndst = NULL;
1042 	struct net_device *tdev;
1043 	int mtu;
1044 	unsigned int psh_hlen = sizeof(struct ipv6hdr) + t->encap_hlen;
1045 	unsigned int max_headroom = psh_hlen;
1046 	bool use_cache = false;
1047 	u8 hop_limit;
1048 	int err = -1;
1049 
1050 	if (t->parms.collect_md) {
1051 		hop_limit = skb_tunnel_info(skb)->key.ttl;
1052 		goto route_lookup;
1053 	} else {
1054 		hop_limit = t->parms.hop_limit;
1055 	}
1056 
1057 	/* NBMA tunnel */
1058 	if (ipv6_addr_any(&t->parms.raddr)) {
1059 		if (skb->protocol == htons(ETH_P_IPV6)) {
1060 			struct in6_addr *addr6;
1061 			struct neighbour *neigh;
1062 			int addr_type;
1063 
1064 			if (!skb_dst(skb))
1065 				goto tx_err_link_failure;
1066 
1067 			neigh = dst_neigh_lookup(skb_dst(skb),
1068 						 &ipv6_hdr(skb)->daddr);
1069 			if (!neigh)
1070 				goto tx_err_link_failure;
1071 
1072 			addr6 = (struct in6_addr *)&neigh->primary_key;
1073 			addr_type = ipv6_addr_type(addr6);
1074 
1075 			if (addr_type == IPV6_ADDR_ANY)
1076 				addr6 = &ipv6_hdr(skb)->daddr;
1077 
1078 			memcpy(&fl6->daddr, addr6, sizeof(fl6->daddr));
1079 			neigh_release(neigh);
1080 		}
1081 	} else if (!(t->parms.flags &
1082 		     (IP6_TNL_F_USE_ORIG_TCLASS | IP6_TNL_F_USE_ORIG_FWMARK))) {
1083 		/* enable the cache only only if the routing decision does
1084 		 * not depend on the current inner header value
1085 		 */
1086 		use_cache = true;
1087 	}
1088 
1089 	if (use_cache)
1090 		dst = dst_cache_get(&t->dst_cache);
1091 
1092 	if (!ip6_tnl_xmit_ctl(t, &fl6->saddr, &fl6->daddr))
1093 		goto tx_err_link_failure;
1094 
1095 	if (!dst) {
1096 route_lookup:
1097 		/* add dsfield to flowlabel for route lookup */
1098 		fl6->flowlabel = ip6_make_flowinfo(dsfield, fl6->flowlabel);
1099 
1100 		dst = ip6_route_output(net, NULL, fl6);
1101 
1102 		if (dst->error)
1103 			goto tx_err_link_failure;
1104 		dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), NULL, 0);
1105 		if (IS_ERR(dst)) {
1106 			err = PTR_ERR(dst);
1107 			dst = NULL;
1108 			goto tx_err_link_failure;
1109 		}
1110 		if (t->parms.collect_md &&
1111 		    ipv6_dev_get_saddr(net, ip6_dst_idev(dst)->dev,
1112 				       &fl6->daddr, 0, &fl6->saddr))
1113 			goto tx_err_link_failure;
1114 		ndst = dst;
1115 	}
1116 
1117 	tdev = dst->dev;
1118 
1119 	if (tdev == dev) {
1120 		stats->collisions++;
1121 		net_warn_ratelimited("%s: Local routing loop detected!\n",
1122 				     t->parms.name);
1123 		goto tx_err_dst_release;
1124 	}
1125 	mtu = dst_mtu(dst) - psh_hlen - t->tun_hlen;
1126 	if (encap_limit >= 0) {
1127 		max_headroom += 8;
1128 		mtu -= 8;
1129 	}
1130 	if (mtu < IPV6_MIN_MTU)
1131 		mtu = IPV6_MIN_MTU;
1132 	if (skb_dst(skb) && !t->parms.collect_md)
1133 		skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
1134 	if (skb->len - t->tun_hlen > mtu && !skb_is_gso(skb)) {
1135 		*pmtu = mtu;
1136 		err = -EMSGSIZE;
1137 		goto tx_err_dst_release;
1138 	}
1139 
1140 	if (t->err_count > 0) {
1141 		if (time_before(jiffies,
1142 				t->err_time + IP6TUNNEL_ERR_TIMEO)) {
1143 			t->err_count--;
1144 
1145 			dst_link_failure(skb);
1146 		} else {
1147 			t->err_count = 0;
1148 		}
1149 	}
1150 
1151 	skb_scrub_packet(skb, !net_eq(t->net, dev_net(dev)));
1152 
1153 	/*
1154 	 * Okay, now see if we can stuff it in the buffer as-is.
1155 	 */
1156 	max_headroom += LL_RESERVED_SPACE(tdev);
1157 
1158 	if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
1159 	    (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
1160 		struct sk_buff *new_skb;
1161 
1162 		new_skb = skb_realloc_headroom(skb, max_headroom);
1163 		if (!new_skb)
1164 			goto tx_err_dst_release;
1165 
1166 		if (skb->sk)
1167 			skb_set_owner_w(new_skb, skb->sk);
1168 		consume_skb(skb);
1169 		skb = new_skb;
1170 	}
1171 
1172 	if (t->parms.collect_md) {
1173 		if (t->encap.type != TUNNEL_ENCAP_NONE)
1174 			goto tx_err_dst_release;
1175 	} else {
1176 		if (use_cache && ndst)
1177 			dst_cache_set_ip6(&t->dst_cache, ndst, &fl6->saddr);
1178 	}
1179 	skb_dst_set(skb, dst);
1180 
1181 	if (encap_limit >= 0) {
1182 		init_tel_txopt(&opt, encap_limit);
1183 		ipv6_push_frag_opts(skb, &opt.ops, &proto);
1184 	}
1185 
1186 	/* Calculate max headroom for all the headers and adjust
1187 	 * needed_headroom if necessary.
1188 	 */
1189 	max_headroom = LL_RESERVED_SPACE(dst->dev) + sizeof(struct ipv6hdr)
1190 			+ dst->header_len + t->hlen;
1191 	if (max_headroom > dev->needed_headroom)
1192 		dev->needed_headroom = max_headroom;
1193 
1194 	err = ip6_tnl_encap(skb, t, &proto, fl6);
1195 	if (err)
1196 		return err;
1197 
1198 	skb_push(skb, sizeof(struct ipv6hdr));
1199 	skb_reset_network_header(skb);
1200 	ipv6h = ipv6_hdr(skb);
1201 	ip6_flow_hdr(ipv6h, dsfield,
1202 		     ip6_make_flowlabel(net, skb, fl6->flowlabel, true, fl6));
1203 	ipv6h->hop_limit = hop_limit;
1204 	ipv6h->nexthdr = proto;
1205 	ipv6h->saddr = fl6->saddr;
1206 	ipv6h->daddr = fl6->daddr;
1207 	ip6tunnel_xmit(NULL, skb, dev);
1208 	return 0;
1209 tx_err_link_failure:
1210 	stats->tx_carrier_errors++;
1211 	dst_link_failure(skb);
1212 tx_err_dst_release:
1213 	dst_release(dst);
1214 	return err;
1215 }
1216 EXPORT_SYMBOL(ip6_tnl_xmit);
1217 
1218 static inline int
1219 ip4ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1220 {
1221 	struct ip6_tnl *t = netdev_priv(dev);
1222 	const struct iphdr  *iph = ip_hdr(skb);
1223 	int encap_limit = -1;
1224 	struct flowi6 fl6;
1225 	__u8 dsfield;
1226 	__u32 mtu;
1227 	u8 tproto;
1228 	int err;
1229 
1230 	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1231 
1232 	tproto = ACCESS_ONCE(t->parms.proto);
1233 	if (tproto != IPPROTO_IPIP && tproto != 0)
1234 		return -1;
1235 
1236 	if (t->parms.collect_md) {
1237 		struct ip_tunnel_info *tun_info;
1238 		const struct ip_tunnel_key *key;
1239 
1240 		tun_info = skb_tunnel_info(skb);
1241 		if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
1242 			     ip_tunnel_info_af(tun_info) != AF_INET6))
1243 			return -1;
1244 		key = &tun_info->key;
1245 		memset(&fl6, 0, sizeof(fl6));
1246 		fl6.flowi6_proto = IPPROTO_IPIP;
1247 		fl6.daddr = key->u.ipv6.dst;
1248 		fl6.flowlabel = key->label;
1249 		dsfield = ip6_tclass(key->label);
1250 	} else {
1251 		if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1252 			encap_limit = t->parms.encap_limit;
1253 
1254 		memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
1255 		fl6.flowi6_proto = IPPROTO_IPIP;
1256 
1257 		if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1258 			dsfield = ipv4_get_dsfield(iph);
1259 		else
1260 			dsfield = ip6_tclass(t->parms.flowinfo);
1261 		if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
1262 			fl6.flowi6_mark = skb->mark;
1263 		else
1264 			fl6.flowi6_mark = t->parms.fwmark;
1265 	}
1266 
1267 	fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
1268 
1269 	if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP6))
1270 		return -1;
1271 
1272 	dsfield = INET_ECN_encapsulate(dsfield, ipv4_get_dsfield(iph));
1273 
1274 	skb_set_inner_ipproto(skb, IPPROTO_IPIP);
1275 
1276 	err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
1277 			   IPPROTO_IPIP);
1278 	if (err != 0) {
1279 		/* XXX: send ICMP error even if DF is not set. */
1280 		if (err == -EMSGSIZE)
1281 			icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
1282 				  htonl(mtu));
1283 		return -1;
1284 	}
1285 
1286 	return 0;
1287 }
1288 
1289 static inline int
1290 ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1291 {
1292 	struct ip6_tnl *t = netdev_priv(dev);
1293 	struct ipv6hdr *ipv6h = ipv6_hdr(skb);
1294 	int encap_limit = -1;
1295 	__u16 offset;
1296 	struct flowi6 fl6;
1297 	__u8 dsfield;
1298 	__u32 mtu;
1299 	u8 tproto;
1300 	int err;
1301 
1302 	tproto = ACCESS_ONCE(t->parms.proto);
1303 	if ((tproto != IPPROTO_IPV6 && tproto != 0) ||
1304 	    ip6_tnl_addr_conflict(t, ipv6h))
1305 		return -1;
1306 
1307 	if (t->parms.collect_md) {
1308 		struct ip_tunnel_info *tun_info;
1309 		const struct ip_tunnel_key *key;
1310 
1311 		tun_info = skb_tunnel_info(skb);
1312 		if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
1313 			     ip_tunnel_info_af(tun_info) != AF_INET6))
1314 			return -1;
1315 		key = &tun_info->key;
1316 		memset(&fl6, 0, sizeof(fl6));
1317 		fl6.flowi6_proto = IPPROTO_IPV6;
1318 		fl6.daddr = key->u.ipv6.dst;
1319 		fl6.flowlabel = key->label;
1320 		dsfield = ip6_tclass(key->label);
1321 	} else {
1322 		offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
1323 		/* ip6_tnl_parse_tlv_enc_lim() might have reallocated skb->head */
1324 		ipv6h = ipv6_hdr(skb);
1325 		if (offset > 0) {
1326 			struct ipv6_tlv_tnl_enc_lim *tel;
1327 
1328 			tel = (void *)&skb_network_header(skb)[offset];
1329 			if (tel->encap_limit == 0) {
1330 				icmpv6_send(skb, ICMPV6_PARAMPROB,
1331 					    ICMPV6_HDR_FIELD, offset + 2);
1332 				return -1;
1333 			}
1334 			encap_limit = tel->encap_limit - 1;
1335 		} else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) {
1336 			encap_limit = t->parms.encap_limit;
1337 		}
1338 
1339 		memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
1340 		fl6.flowi6_proto = IPPROTO_IPV6;
1341 
1342 		if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1343 			dsfield = ipv6_get_dsfield(ipv6h);
1344 		else
1345 			dsfield = ip6_tclass(t->parms.flowinfo);
1346 		if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
1347 			fl6.flowlabel |= ip6_flowlabel(ipv6h);
1348 		if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
1349 			fl6.flowi6_mark = skb->mark;
1350 		else
1351 			fl6.flowi6_mark = t->parms.fwmark;
1352 	}
1353 
1354 	fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
1355 
1356 	if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP6))
1357 		return -1;
1358 
1359 	dsfield = INET_ECN_encapsulate(dsfield, ipv6_get_dsfield(ipv6h));
1360 
1361 	skb_set_inner_ipproto(skb, IPPROTO_IPV6);
1362 
1363 	err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
1364 			   IPPROTO_IPV6);
1365 	if (err != 0) {
1366 		if (err == -EMSGSIZE)
1367 			icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
1368 		return -1;
1369 	}
1370 
1371 	return 0;
1372 }
1373 
1374 static netdev_tx_t
1375 ip6_tnl_start_xmit(struct sk_buff *skb, struct net_device *dev)
1376 {
1377 	struct ip6_tnl *t = netdev_priv(dev);
1378 	struct net_device_stats *stats = &t->dev->stats;
1379 	int ret;
1380 
1381 	switch (skb->protocol) {
1382 	case htons(ETH_P_IP):
1383 		ret = ip4ip6_tnl_xmit(skb, dev);
1384 		break;
1385 	case htons(ETH_P_IPV6):
1386 		ret = ip6ip6_tnl_xmit(skb, dev);
1387 		break;
1388 	default:
1389 		goto tx_err;
1390 	}
1391 
1392 	if (ret < 0)
1393 		goto tx_err;
1394 
1395 	return NETDEV_TX_OK;
1396 
1397 tx_err:
1398 	stats->tx_errors++;
1399 	stats->tx_dropped++;
1400 	kfree_skb(skb);
1401 	return NETDEV_TX_OK;
1402 }
1403 
1404 static void ip6_tnl_link_config(struct ip6_tnl *t)
1405 {
1406 	struct net_device *dev = t->dev;
1407 	struct __ip6_tnl_parm *p = &t->parms;
1408 	struct flowi6 *fl6 = &t->fl.u.ip6;
1409 	int t_hlen;
1410 
1411 	memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
1412 	memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
1413 
1414 	/* Set up flowi template */
1415 	fl6->saddr = p->laddr;
1416 	fl6->daddr = p->raddr;
1417 	fl6->flowi6_oif = p->link;
1418 	fl6->flowlabel = 0;
1419 
1420 	if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
1421 		fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
1422 	if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
1423 		fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
1424 
1425 	p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
1426 	p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
1427 
1428 	if (p->flags&IP6_TNL_F_CAP_XMIT && p->flags&IP6_TNL_F_CAP_RCV)
1429 		dev->flags |= IFF_POINTOPOINT;
1430 	else
1431 		dev->flags &= ~IFF_POINTOPOINT;
1432 
1433 	t->tun_hlen = 0;
1434 	t->hlen = t->encap_hlen + t->tun_hlen;
1435 	t_hlen = t->hlen + sizeof(struct ipv6hdr);
1436 
1437 	if (p->flags & IP6_TNL_F_CAP_XMIT) {
1438 		int strict = (ipv6_addr_type(&p->raddr) &
1439 			      (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
1440 
1441 		struct rt6_info *rt = rt6_lookup(t->net,
1442 						 &p->raddr, &p->laddr,
1443 						 p->link, strict);
1444 
1445 		if (!rt)
1446 			return;
1447 
1448 		if (rt->dst.dev) {
1449 			dev->hard_header_len = rt->dst.dev->hard_header_len +
1450 				t_hlen;
1451 
1452 			dev->mtu = rt->dst.dev->mtu - t_hlen;
1453 			if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1454 				dev->mtu -= 8;
1455 
1456 			if (dev->mtu < IPV6_MIN_MTU)
1457 				dev->mtu = IPV6_MIN_MTU;
1458 		}
1459 		ip6_rt_put(rt);
1460 	}
1461 }
1462 
1463 /**
1464  * ip6_tnl_change - update the tunnel parameters
1465  *   @t: tunnel to be changed
1466  *   @p: tunnel configuration parameters
1467  *
1468  * Description:
1469  *   ip6_tnl_change() updates the tunnel parameters
1470  **/
1471 
1472 static int
1473 ip6_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p)
1474 {
1475 	t->parms.laddr = p->laddr;
1476 	t->parms.raddr = p->raddr;
1477 	t->parms.flags = p->flags;
1478 	t->parms.hop_limit = p->hop_limit;
1479 	t->parms.encap_limit = p->encap_limit;
1480 	t->parms.flowinfo = p->flowinfo;
1481 	t->parms.link = p->link;
1482 	t->parms.proto = p->proto;
1483 	t->parms.fwmark = p->fwmark;
1484 	dst_cache_reset(&t->dst_cache);
1485 	ip6_tnl_link_config(t);
1486 	return 0;
1487 }
1488 
1489 static int ip6_tnl_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
1490 {
1491 	struct net *net = t->net;
1492 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1493 	int err;
1494 
1495 	ip6_tnl_unlink(ip6n, t);
1496 	synchronize_net();
1497 	err = ip6_tnl_change(t, p);
1498 	ip6_tnl_link(ip6n, t);
1499 	netdev_state_change(t->dev);
1500 	return err;
1501 }
1502 
1503 static int ip6_tnl0_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
1504 {
1505 	/* for default tnl0 device allow to change only the proto */
1506 	t->parms.proto = p->proto;
1507 	netdev_state_change(t->dev);
1508 	return 0;
1509 }
1510 
1511 static void
1512 ip6_tnl_parm_from_user(struct __ip6_tnl_parm *p, const struct ip6_tnl_parm *u)
1513 {
1514 	p->laddr = u->laddr;
1515 	p->raddr = u->raddr;
1516 	p->flags = u->flags;
1517 	p->hop_limit = u->hop_limit;
1518 	p->encap_limit = u->encap_limit;
1519 	p->flowinfo = u->flowinfo;
1520 	p->link = u->link;
1521 	p->proto = u->proto;
1522 	memcpy(p->name, u->name, sizeof(u->name));
1523 }
1524 
1525 static void
1526 ip6_tnl_parm_to_user(struct ip6_tnl_parm *u, const struct __ip6_tnl_parm *p)
1527 {
1528 	u->laddr = p->laddr;
1529 	u->raddr = p->raddr;
1530 	u->flags = p->flags;
1531 	u->hop_limit = p->hop_limit;
1532 	u->encap_limit = p->encap_limit;
1533 	u->flowinfo = p->flowinfo;
1534 	u->link = p->link;
1535 	u->proto = p->proto;
1536 	memcpy(u->name, p->name, sizeof(u->name));
1537 }
1538 
1539 /**
1540  * ip6_tnl_ioctl - configure ipv6 tunnels from userspace
1541  *   @dev: virtual device associated with tunnel
1542  *   @ifr: parameters passed from userspace
1543  *   @cmd: command to be performed
1544  *
1545  * Description:
1546  *   ip6_tnl_ioctl() is used for managing IPv6 tunnels
1547  *   from userspace.
1548  *
1549  *   The possible commands are the following:
1550  *     %SIOCGETTUNNEL: get tunnel parameters for device
1551  *     %SIOCADDTUNNEL: add tunnel matching given tunnel parameters
1552  *     %SIOCCHGTUNNEL: change tunnel parameters to those given
1553  *     %SIOCDELTUNNEL: delete tunnel
1554  *
1555  *   The fallback device "ip6tnl0", created during module
1556  *   initialization, can be used for creating other tunnel devices.
1557  *
1558  * Return:
1559  *   0 on success,
1560  *   %-EFAULT if unable to copy data to or from userspace,
1561  *   %-EPERM if current process hasn't %CAP_NET_ADMIN set
1562  *   %-EINVAL if passed tunnel parameters are invalid,
1563  *   %-EEXIST if changing a tunnel's parameters would cause a conflict
1564  *   %-ENODEV if attempting to change or delete a nonexisting device
1565  **/
1566 
1567 static int
1568 ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1569 {
1570 	int err = 0;
1571 	struct ip6_tnl_parm p;
1572 	struct __ip6_tnl_parm p1;
1573 	struct ip6_tnl *t = netdev_priv(dev);
1574 	struct net *net = t->net;
1575 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1576 
1577 	memset(&p1, 0, sizeof(p1));
1578 
1579 	switch (cmd) {
1580 	case SIOCGETTUNNEL:
1581 		if (dev == ip6n->fb_tnl_dev) {
1582 			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1583 				err = -EFAULT;
1584 				break;
1585 			}
1586 			ip6_tnl_parm_from_user(&p1, &p);
1587 			t = ip6_tnl_locate(net, &p1, 0);
1588 			if (IS_ERR(t))
1589 				t = netdev_priv(dev);
1590 		} else {
1591 			memset(&p, 0, sizeof(p));
1592 		}
1593 		ip6_tnl_parm_to_user(&p, &t->parms);
1594 		if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) {
1595 			err = -EFAULT;
1596 		}
1597 		break;
1598 	case SIOCADDTUNNEL:
1599 	case SIOCCHGTUNNEL:
1600 		err = -EPERM;
1601 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1602 			break;
1603 		err = -EFAULT;
1604 		if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1605 			break;
1606 		err = -EINVAL;
1607 		if (p.proto != IPPROTO_IPV6 && p.proto != IPPROTO_IPIP &&
1608 		    p.proto != 0)
1609 			break;
1610 		ip6_tnl_parm_from_user(&p1, &p);
1611 		t = ip6_tnl_locate(net, &p1, cmd == SIOCADDTUNNEL);
1612 		if (cmd == SIOCCHGTUNNEL) {
1613 			if (!IS_ERR(t)) {
1614 				if (t->dev != dev) {
1615 					err = -EEXIST;
1616 					break;
1617 				}
1618 			} else
1619 				t = netdev_priv(dev);
1620 			if (dev == ip6n->fb_tnl_dev)
1621 				err = ip6_tnl0_update(t, &p1);
1622 			else
1623 				err = ip6_tnl_update(t, &p1);
1624 		}
1625 		if (!IS_ERR(t)) {
1626 			err = 0;
1627 			ip6_tnl_parm_to_user(&p, &t->parms);
1628 			if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1629 				err = -EFAULT;
1630 
1631 		} else {
1632 			err = PTR_ERR(t);
1633 		}
1634 		break;
1635 	case SIOCDELTUNNEL:
1636 		err = -EPERM;
1637 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1638 			break;
1639 
1640 		if (dev == ip6n->fb_tnl_dev) {
1641 			err = -EFAULT;
1642 			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1643 				break;
1644 			err = -ENOENT;
1645 			ip6_tnl_parm_from_user(&p1, &p);
1646 			t = ip6_tnl_locate(net, &p1, 0);
1647 			if (IS_ERR(t))
1648 				break;
1649 			err = -EPERM;
1650 			if (t->dev == ip6n->fb_tnl_dev)
1651 				break;
1652 			dev = t->dev;
1653 		}
1654 		err = 0;
1655 		unregister_netdevice(dev);
1656 		break;
1657 	default:
1658 		err = -EINVAL;
1659 	}
1660 	return err;
1661 }
1662 
1663 /**
1664  * ip6_tnl_change_mtu - change mtu manually for tunnel device
1665  *   @dev: virtual device associated with tunnel
1666  *   @new_mtu: the new mtu
1667  *
1668  * Return:
1669  *   0 on success,
1670  *   %-EINVAL if mtu too small
1671  **/
1672 
1673 int ip6_tnl_change_mtu(struct net_device *dev, int new_mtu)
1674 {
1675 	struct ip6_tnl *tnl = netdev_priv(dev);
1676 
1677 	if (tnl->parms.proto == IPPROTO_IPIP) {
1678 		if (new_mtu < ETH_MIN_MTU)
1679 			return -EINVAL;
1680 	} else {
1681 		if (new_mtu < IPV6_MIN_MTU)
1682 			return -EINVAL;
1683 	}
1684 	if (new_mtu > 0xFFF8 - dev->hard_header_len)
1685 		return -EINVAL;
1686 	dev->mtu = new_mtu;
1687 	return 0;
1688 }
1689 EXPORT_SYMBOL(ip6_tnl_change_mtu);
1690 
1691 int ip6_tnl_get_iflink(const struct net_device *dev)
1692 {
1693 	struct ip6_tnl *t = netdev_priv(dev);
1694 
1695 	return t->parms.link;
1696 }
1697 EXPORT_SYMBOL(ip6_tnl_get_iflink);
1698 
1699 int ip6_tnl_encap_add_ops(const struct ip6_tnl_encap_ops *ops,
1700 			  unsigned int num)
1701 {
1702 	if (num >= MAX_IPTUN_ENCAP_OPS)
1703 		return -ERANGE;
1704 
1705 	return !cmpxchg((const struct ip6_tnl_encap_ops **)
1706 			&ip6tun_encaps[num],
1707 			NULL, ops) ? 0 : -1;
1708 }
1709 EXPORT_SYMBOL(ip6_tnl_encap_add_ops);
1710 
1711 int ip6_tnl_encap_del_ops(const struct ip6_tnl_encap_ops *ops,
1712 			  unsigned int num)
1713 {
1714 	int ret;
1715 
1716 	if (num >= MAX_IPTUN_ENCAP_OPS)
1717 		return -ERANGE;
1718 
1719 	ret = (cmpxchg((const struct ip6_tnl_encap_ops **)
1720 		       &ip6tun_encaps[num],
1721 		       ops, NULL) == ops) ? 0 : -1;
1722 
1723 	synchronize_net();
1724 
1725 	return ret;
1726 }
1727 EXPORT_SYMBOL(ip6_tnl_encap_del_ops);
1728 
1729 int ip6_tnl_encap_setup(struct ip6_tnl *t,
1730 			struct ip_tunnel_encap *ipencap)
1731 {
1732 	int hlen;
1733 
1734 	memset(&t->encap, 0, sizeof(t->encap));
1735 
1736 	hlen = ip6_encap_hlen(ipencap);
1737 	if (hlen < 0)
1738 		return hlen;
1739 
1740 	t->encap.type = ipencap->type;
1741 	t->encap.sport = ipencap->sport;
1742 	t->encap.dport = ipencap->dport;
1743 	t->encap.flags = ipencap->flags;
1744 
1745 	t->encap_hlen = hlen;
1746 	t->hlen = t->encap_hlen + t->tun_hlen;
1747 
1748 	return 0;
1749 }
1750 EXPORT_SYMBOL_GPL(ip6_tnl_encap_setup);
1751 
1752 static const struct net_device_ops ip6_tnl_netdev_ops = {
1753 	.ndo_init	= ip6_tnl_dev_init,
1754 	.ndo_uninit	= ip6_tnl_dev_uninit,
1755 	.ndo_start_xmit = ip6_tnl_start_xmit,
1756 	.ndo_do_ioctl	= ip6_tnl_ioctl,
1757 	.ndo_change_mtu = ip6_tnl_change_mtu,
1758 	.ndo_get_stats	= ip6_get_stats,
1759 	.ndo_get_iflink = ip6_tnl_get_iflink,
1760 };
1761 
1762 #define IPXIPX_FEATURES (NETIF_F_SG |		\
1763 			 NETIF_F_FRAGLIST |	\
1764 			 NETIF_F_HIGHDMA |	\
1765 			 NETIF_F_GSO_SOFTWARE |	\
1766 			 NETIF_F_HW_CSUM)
1767 
1768 /**
1769  * ip6_tnl_dev_setup - setup virtual tunnel device
1770  *   @dev: virtual device associated with tunnel
1771  *
1772  * Description:
1773  *   Initialize function pointers and device parameters
1774  **/
1775 
1776 static void ip6_tnl_dev_setup(struct net_device *dev)
1777 {
1778 	dev->netdev_ops = &ip6_tnl_netdev_ops;
1779 	dev->needs_free_netdev = true;
1780 	dev->priv_destructor = ip6_dev_free;
1781 
1782 	dev->type = ARPHRD_TUNNEL6;
1783 	dev->flags |= IFF_NOARP;
1784 	dev->addr_len = sizeof(struct in6_addr);
1785 	dev->features |= NETIF_F_LLTX;
1786 	netif_keep_dst(dev);
1787 
1788 	dev->features		|= IPXIPX_FEATURES;
1789 	dev->hw_features	|= IPXIPX_FEATURES;
1790 
1791 	/* This perm addr will be used as interface identifier by IPv6 */
1792 	dev->addr_assign_type = NET_ADDR_RANDOM;
1793 	eth_random_addr(dev->perm_addr);
1794 }
1795 
1796 
1797 /**
1798  * ip6_tnl_dev_init_gen - general initializer for all tunnel devices
1799  *   @dev: virtual device associated with tunnel
1800  **/
1801 
1802 static inline int
1803 ip6_tnl_dev_init_gen(struct net_device *dev)
1804 {
1805 	struct ip6_tnl *t = netdev_priv(dev);
1806 	int ret;
1807 	int t_hlen;
1808 
1809 	t->dev = dev;
1810 	t->net = dev_net(dev);
1811 	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1812 	if (!dev->tstats)
1813 		return -ENOMEM;
1814 
1815 	ret = dst_cache_init(&t->dst_cache, GFP_KERNEL);
1816 	if (ret)
1817 		goto free_stats;
1818 
1819 	ret = gro_cells_init(&t->gro_cells, dev);
1820 	if (ret)
1821 		goto destroy_dst;
1822 
1823 	t->tun_hlen = 0;
1824 	t->hlen = t->encap_hlen + t->tun_hlen;
1825 	t_hlen = t->hlen + sizeof(struct ipv6hdr);
1826 
1827 	dev->type = ARPHRD_TUNNEL6;
1828 	dev->hard_header_len = LL_MAX_HEADER + t_hlen;
1829 	dev->mtu = ETH_DATA_LEN - t_hlen;
1830 	if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1831 		dev->mtu -= 8;
1832 	dev->min_mtu = ETH_MIN_MTU;
1833 	dev->max_mtu = 0xFFF8 - dev->hard_header_len;
1834 
1835 	return 0;
1836 
1837 destroy_dst:
1838 	dst_cache_destroy(&t->dst_cache);
1839 free_stats:
1840 	free_percpu(dev->tstats);
1841 	dev->tstats = NULL;
1842 
1843 	return ret;
1844 }
1845 
1846 /**
1847  * ip6_tnl_dev_init - initializer for all non fallback tunnel devices
1848  *   @dev: virtual device associated with tunnel
1849  **/
1850 
1851 static int ip6_tnl_dev_init(struct net_device *dev)
1852 {
1853 	struct ip6_tnl *t = netdev_priv(dev);
1854 	int err = ip6_tnl_dev_init_gen(dev);
1855 
1856 	if (err)
1857 		return err;
1858 	ip6_tnl_link_config(t);
1859 	if (t->parms.collect_md) {
1860 		dev->features |= NETIF_F_NETNS_LOCAL;
1861 		netif_keep_dst(dev);
1862 	}
1863 	return 0;
1864 }
1865 
1866 /**
1867  * ip6_fb_tnl_dev_init - initializer for fallback tunnel device
1868  *   @dev: fallback device
1869  *
1870  * Return: 0
1871  **/
1872 
1873 static int __net_init ip6_fb_tnl_dev_init(struct net_device *dev)
1874 {
1875 	struct ip6_tnl *t = netdev_priv(dev);
1876 	struct net *net = dev_net(dev);
1877 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1878 
1879 	t->parms.proto = IPPROTO_IPV6;
1880 	dev_hold(dev);
1881 
1882 	rcu_assign_pointer(ip6n->tnls_wc[0], t);
1883 	return 0;
1884 }
1885 
1886 static int ip6_tnl_validate(struct nlattr *tb[], struct nlattr *data[])
1887 {
1888 	u8 proto;
1889 
1890 	if (!data || !data[IFLA_IPTUN_PROTO])
1891 		return 0;
1892 
1893 	proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1894 	if (proto != IPPROTO_IPV6 &&
1895 	    proto != IPPROTO_IPIP &&
1896 	    proto != 0)
1897 		return -EINVAL;
1898 
1899 	return 0;
1900 }
1901 
1902 static void ip6_tnl_netlink_parms(struct nlattr *data[],
1903 				  struct __ip6_tnl_parm *parms)
1904 {
1905 	memset(parms, 0, sizeof(*parms));
1906 
1907 	if (!data)
1908 		return;
1909 
1910 	if (data[IFLA_IPTUN_LINK])
1911 		parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
1912 
1913 	if (data[IFLA_IPTUN_LOCAL])
1914 		parms->laddr = nla_get_in6_addr(data[IFLA_IPTUN_LOCAL]);
1915 
1916 	if (data[IFLA_IPTUN_REMOTE])
1917 		parms->raddr = nla_get_in6_addr(data[IFLA_IPTUN_REMOTE]);
1918 
1919 	if (data[IFLA_IPTUN_TTL])
1920 		parms->hop_limit = nla_get_u8(data[IFLA_IPTUN_TTL]);
1921 
1922 	if (data[IFLA_IPTUN_ENCAP_LIMIT])
1923 		parms->encap_limit = nla_get_u8(data[IFLA_IPTUN_ENCAP_LIMIT]);
1924 
1925 	if (data[IFLA_IPTUN_FLOWINFO])
1926 		parms->flowinfo = nla_get_be32(data[IFLA_IPTUN_FLOWINFO]);
1927 
1928 	if (data[IFLA_IPTUN_FLAGS])
1929 		parms->flags = nla_get_u32(data[IFLA_IPTUN_FLAGS]);
1930 
1931 	if (data[IFLA_IPTUN_PROTO])
1932 		parms->proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1933 
1934 	if (data[IFLA_IPTUN_COLLECT_METADATA])
1935 		parms->collect_md = true;
1936 
1937 	if (data[IFLA_IPTUN_FWMARK])
1938 		parms->fwmark = nla_get_u32(data[IFLA_IPTUN_FWMARK]);
1939 }
1940 
1941 static bool ip6_tnl_netlink_encap_parms(struct nlattr *data[],
1942 					struct ip_tunnel_encap *ipencap)
1943 {
1944 	bool ret = false;
1945 
1946 	memset(ipencap, 0, sizeof(*ipencap));
1947 
1948 	if (!data)
1949 		return ret;
1950 
1951 	if (data[IFLA_IPTUN_ENCAP_TYPE]) {
1952 		ret = true;
1953 		ipencap->type = nla_get_u16(data[IFLA_IPTUN_ENCAP_TYPE]);
1954 	}
1955 
1956 	if (data[IFLA_IPTUN_ENCAP_FLAGS]) {
1957 		ret = true;
1958 		ipencap->flags = nla_get_u16(data[IFLA_IPTUN_ENCAP_FLAGS]);
1959 	}
1960 
1961 	if (data[IFLA_IPTUN_ENCAP_SPORT]) {
1962 		ret = true;
1963 		ipencap->sport = nla_get_be16(data[IFLA_IPTUN_ENCAP_SPORT]);
1964 	}
1965 
1966 	if (data[IFLA_IPTUN_ENCAP_DPORT]) {
1967 		ret = true;
1968 		ipencap->dport = nla_get_be16(data[IFLA_IPTUN_ENCAP_DPORT]);
1969 	}
1970 
1971 	return ret;
1972 }
1973 
1974 static int ip6_tnl_newlink(struct net *src_net, struct net_device *dev,
1975 			   struct nlattr *tb[], struct nlattr *data[])
1976 {
1977 	struct net *net = dev_net(dev);
1978 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1979 	struct ip6_tnl *nt, *t;
1980 	struct ip_tunnel_encap ipencap;
1981 
1982 	nt = netdev_priv(dev);
1983 
1984 	if (ip6_tnl_netlink_encap_parms(data, &ipencap)) {
1985 		int err = ip6_tnl_encap_setup(nt, &ipencap);
1986 
1987 		if (err < 0)
1988 			return err;
1989 	}
1990 
1991 	ip6_tnl_netlink_parms(data, &nt->parms);
1992 
1993 	if (nt->parms.collect_md) {
1994 		if (rtnl_dereference(ip6n->collect_md_tun))
1995 			return -EEXIST;
1996 	} else {
1997 		t = ip6_tnl_locate(net, &nt->parms, 0);
1998 		if (!IS_ERR(t))
1999 			return -EEXIST;
2000 	}
2001 
2002 	return ip6_tnl_create2(dev);
2003 }
2004 
2005 static int ip6_tnl_changelink(struct net_device *dev, struct nlattr *tb[],
2006 			      struct nlattr *data[])
2007 {
2008 	struct ip6_tnl *t = netdev_priv(dev);
2009 	struct __ip6_tnl_parm p;
2010 	struct net *net = t->net;
2011 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2012 	struct ip_tunnel_encap ipencap;
2013 
2014 	if (dev == ip6n->fb_tnl_dev)
2015 		return -EINVAL;
2016 
2017 	if (ip6_tnl_netlink_encap_parms(data, &ipencap)) {
2018 		int err = ip6_tnl_encap_setup(t, &ipencap);
2019 
2020 		if (err < 0)
2021 			return err;
2022 	}
2023 	ip6_tnl_netlink_parms(data, &p);
2024 	if (p.collect_md)
2025 		return -EINVAL;
2026 
2027 	t = ip6_tnl_locate(net, &p, 0);
2028 	if (!IS_ERR(t)) {
2029 		if (t->dev != dev)
2030 			return -EEXIST;
2031 	} else
2032 		t = netdev_priv(dev);
2033 
2034 	return ip6_tnl_update(t, &p);
2035 }
2036 
2037 static void ip6_tnl_dellink(struct net_device *dev, struct list_head *head)
2038 {
2039 	struct net *net = dev_net(dev);
2040 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2041 
2042 	if (dev != ip6n->fb_tnl_dev)
2043 		unregister_netdevice_queue(dev, head);
2044 }
2045 
2046 static size_t ip6_tnl_get_size(const struct net_device *dev)
2047 {
2048 	return
2049 		/* IFLA_IPTUN_LINK */
2050 		nla_total_size(4) +
2051 		/* IFLA_IPTUN_LOCAL */
2052 		nla_total_size(sizeof(struct in6_addr)) +
2053 		/* IFLA_IPTUN_REMOTE */
2054 		nla_total_size(sizeof(struct in6_addr)) +
2055 		/* IFLA_IPTUN_TTL */
2056 		nla_total_size(1) +
2057 		/* IFLA_IPTUN_ENCAP_LIMIT */
2058 		nla_total_size(1) +
2059 		/* IFLA_IPTUN_FLOWINFO */
2060 		nla_total_size(4) +
2061 		/* IFLA_IPTUN_FLAGS */
2062 		nla_total_size(4) +
2063 		/* IFLA_IPTUN_PROTO */
2064 		nla_total_size(1) +
2065 		/* IFLA_IPTUN_ENCAP_TYPE */
2066 		nla_total_size(2) +
2067 		/* IFLA_IPTUN_ENCAP_FLAGS */
2068 		nla_total_size(2) +
2069 		/* IFLA_IPTUN_ENCAP_SPORT */
2070 		nla_total_size(2) +
2071 		/* IFLA_IPTUN_ENCAP_DPORT */
2072 		nla_total_size(2) +
2073 		/* IFLA_IPTUN_COLLECT_METADATA */
2074 		nla_total_size(0) +
2075 		/* IFLA_IPTUN_FWMARK */
2076 		nla_total_size(4) +
2077 		0;
2078 }
2079 
2080 static int ip6_tnl_fill_info(struct sk_buff *skb, const struct net_device *dev)
2081 {
2082 	struct ip6_tnl *tunnel = netdev_priv(dev);
2083 	struct __ip6_tnl_parm *parm = &tunnel->parms;
2084 
2085 	if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
2086 	    nla_put_in6_addr(skb, IFLA_IPTUN_LOCAL, &parm->laddr) ||
2087 	    nla_put_in6_addr(skb, IFLA_IPTUN_REMOTE, &parm->raddr) ||
2088 	    nla_put_u8(skb, IFLA_IPTUN_TTL, parm->hop_limit) ||
2089 	    nla_put_u8(skb, IFLA_IPTUN_ENCAP_LIMIT, parm->encap_limit) ||
2090 	    nla_put_be32(skb, IFLA_IPTUN_FLOWINFO, parm->flowinfo) ||
2091 	    nla_put_u32(skb, IFLA_IPTUN_FLAGS, parm->flags) ||
2092 	    nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->proto) ||
2093 	    nla_put_u32(skb, IFLA_IPTUN_FWMARK, parm->fwmark))
2094 		goto nla_put_failure;
2095 
2096 	if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE, tunnel->encap.type) ||
2097 	    nla_put_be16(skb, IFLA_IPTUN_ENCAP_SPORT, tunnel->encap.sport) ||
2098 	    nla_put_be16(skb, IFLA_IPTUN_ENCAP_DPORT, tunnel->encap.dport) ||
2099 	    nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS, tunnel->encap.flags))
2100 		goto nla_put_failure;
2101 
2102 	if (parm->collect_md)
2103 		if (nla_put_flag(skb, IFLA_IPTUN_COLLECT_METADATA))
2104 			goto nla_put_failure;
2105 
2106 	return 0;
2107 
2108 nla_put_failure:
2109 	return -EMSGSIZE;
2110 }
2111 
2112 struct net *ip6_tnl_get_link_net(const struct net_device *dev)
2113 {
2114 	struct ip6_tnl *tunnel = netdev_priv(dev);
2115 
2116 	return tunnel->net;
2117 }
2118 EXPORT_SYMBOL(ip6_tnl_get_link_net);
2119 
2120 static const struct nla_policy ip6_tnl_policy[IFLA_IPTUN_MAX + 1] = {
2121 	[IFLA_IPTUN_LINK]		= { .type = NLA_U32 },
2122 	[IFLA_IPTUN_LOCAL]		= { .len = sizeof(struct in6_addr) },
2123 	[IFLA_IPTUN_REMOTE]		= { .len = sizeof(struct in6_addr) },
2124 	[IFLA_IPTUN_TTL]		= { .type = NLA_U8 },
2125 	[IFLA_IPTUN_ENCAP_LIMIT]	= { .type = NLA_U8 },
2126 	[IFLA_IPTUN_FLOWINFO]		= { .type = NLA_U32 },
2127 	[IFLA_IPTUN_FLAGS]		= { .type = NLA_U32 },
2128 	[IFLA_IPTUN_PROTO]		= { .type = NLA_U8 },
2129 	[IFLA_IPTUN_ENCAP_TYPE]		= { .type = NLA_U16 },
2130 	[IFLA_IPTUN_ENCAP_FLAGS]	= { .type = NLA_U16 },
2131 	[IFLA_IPTUN_ENCAP_SPORT]	= { .type = NLA_U16 },
2132 	[IFLA_IPTUN_ENCAP_DPORT]	= { .type = NLA_U16 },
2133 	[IFLA_IPTUN_COLLECT_METADATA]	= { .type = NLA_FLAG },
2134 	[IFLA_IPTUN_FWMARK]		= { .type = NLA_U32 },
2135 };
2136 
2137 static struct rtnl_link_ops ip6_link_ops __read_mostly = {
2138 	.kind		= "ip6tnl",
2139 	.maxtype	= IFLA_IPTUN_MAX,
2140 	.policy		= ip6_tnl_policy,
2141 	.priv_size	= sizeof(struct ip6_tnl),
2142 	.setup		= ip6_tnl_dev_setup,
2143 	.validate	= ip6_tnl_validate,
2144 	.newlink	= ip6_tnl_newlink,
2145 	.changelink	= ip6_tnl_changelink,
2146 	.dellink	= ip6_tnl_dellink,
2147 	.get_size	= ip6_tnl_get_size,
2148 	.fill_info	= ip6_tnl_fill_info,
2149 	.get_link_net	= ip6_tnl_get_link_net,
2150 };
2151 
2152 static struct xfrm6_tunnel ip4ip6_handler __read_mostly = {
2153 	.handler	= ip4ip6_rcv,
2154 	.err_handler	= ip4ip6_err,
2155 	.priority	=	1,
2156 };
2157 
2158 static struct xfrm6_tunnel ip6ip6_handler __read_mostly = {
2159 	.handler	= ip6ip6_rcv,
2160 	.err_handler	= ip6ip6_err,
2161 	.priority	=	1,
2162 };
2163 
2164 static void __net_exit ip6_tnl_destroy_tunnels(struct net *net)
2165 {
2166 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2167 	struct net_device *dev, *aux;
2168 	int h;
2169 	struct ip6_tnl *t;
2170 	LIST_HEAD(list);
2171 
2172 	for_each_netdev_safe(net, dev, aux)
2173 		if (dev->rtnl_link_ops == &ip6_link_ops)
2174 			unregister_netdevice_queue(dev, &list);
2175 
2176 	for (h = 0; h < IP6_TUNNEL_HASH_SIZE; h++) {
2177 		t = rtnl_dereference(ip6n->tnls_r_l[h]);
2178 		while (t) {
2179 			/* If dev is in the same netns, it has already
2180 			 * been added to the list by the previous loop.
2181 			 */
2182 			if (!net_eq(dev_net(t->dev), net))
2183 				unregister_netdevice_queue(t->dev, &list);
2184 			t = rtnl_dereference(t->next);
2185 		}
2186 	}
2187 
2188 	unregister_netdevice_many(&list);
2189 }
2190 
2191 static int __net_init ip6_tnl_init_net(struct net *net)
2192 {
2193 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2194 	struct ip6_tnl *t = NULL;
2195 	int err;
2196 
2197 	ip6n->tnls[0] = ip6n->tnls_wc;
2198 	ip6n->tnls[1] = ip6n->tnls_r_l;
2199 
2200 	err = -ENOMEM;
2201 	ip6n->fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6tnl0",
2202 					NET_NAME_UNKNOWN, ip6_tnl_dev_setup);
2203 
2204 	if (!ip6n->fb_tnl_dev)
2205 		goto err_alloc_dev;
2206 	dev_net_set(ip6n->fb_tnl_dev, net);
2207 	ip6n->fb_tnl_dev->rtnl_link_ops = &ip6_link_ops;
2208 	/* FB netdevice is special: we have one, and only one per netns.
2209 	 * Allowing to move it to another netns is clearly unsafe.
2210 	 */
2211 	ip6n->fb_tnl_dev->features |= NETIF_F_NETNS_LOCAL;
2212 
2213 	err = ip6_fb_tnl_dev_init(ip6n->fb_tnl_dev);
2214 	if (err < 0)
2215 		goto err_register;
2216 
2217 	err = register_netdev(ip6n->fb_tnl_dev);
2218 	if (err < 0)
2219 		goto err_register;
2220 
2221 	t = netdev_priv(ip6n->fb_tnl_dev);
2222 
2223 	strcpy(t->parms.name, ip6n->fb_tnl_dev->name);
2224 	return 0;
2225 
2226 err_register:
2227 	free_netdev(ip6n->fb_tnl_dev);
2228 err_alloc_dev:
2229 	return err;
2230 }
2231 
2232 static void __net_exit ip6_tnl_exit_net(struct net *net)
2233 {
2234 	rtnl_lock();
2235 	ip6_tnl_destroy_tunnels(net);
2236 	rtnl_unlock();
2237 }
2238 
2239 static struct pernet_operations ip6_tnl_net_ops = {
2240 	.init = ip6_tnl_init_net,
2241 	.exit = ip6_tnl_exit_net,
2242 	.id   = &ip6_tnl_net_id,
2243 	.size = sizeof(struct ip6_tnl_net),
2244 };
2245 
2246 /**
2247  * ip6_tunnel_init - register protocol and reserve needed resources
2248  *
2249  * Return: 0 on success
2250  **/
2251 
2252 static int __init ip6_tunnel_init(void)
2253 {
2254 	int  err;
2255 
2256 	err = register_pernet_device(&ip6_tnl_net_ops);
2257 	if (err < 0)
2258 		goto out_pernet;
2259 
2260 	err = xfrm6_tunnel_register(&ip4ip6_handler, AF_INET);
2261 	if (err < 0) {
2262 		pr_err("%s: can't register ip4ip6\n", __func__);
2263 		goto out_ip4ip6;
2264 	}
2265 
2266 	err = xfrm6_tunnel_register(&ip6ip6_handler, AF_INET6);
2267 	if (err < 0) {
2268 		pr_err("%s: can't register ip6ip6\n", __func__);
2269 		goto out_ip6ip6;
2270 	}
2271 	err = rtnl_link_register(&ip6_link_ops);
2272 	if (err < 0)
2273 		goto rtnl_link_failed;
2274 
2275 	return 0;
2276 
2277 rtnl_link_failed:
2278 	xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6);
2279 out_ip6ip6:
2280 	xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET);
2281 out_ip4ip6:
2282 	unregister_pernet_device(&ip6_tnl_net_ops);
2283 out_pernet:
2284 	return err;
2285 }
2286 
2287 /**
2288  * ip6_tunnel_cleanup - free resources and unregister protocol
2289  **/
2290 
2291 static void __exit ip6_tunnel_cleanup(void)
2292 {
2293 	rtnl_link_unregister(&ip6_link_ops);
2294 	if (xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET))
2295 		pr_info("%s: can't deregister ip4ip6\n", __func__);
2296 
2297 	if (xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6))
2298 		pr_info("%s: can't deregister ip6ip6\n", __func__);
2299 
2300 	unregister_pernet_device(&ip6_tnl_net_ops);
2301 }
2302 
2303 module_init(ip6_tunnel_init);
2304 module_exit(ip6_tunnel_cleanup);
2305