xref: /openbmc/linux/net/ipv6/ip6_tunnel.c (revision 680ef72a)
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 && t->dev->flags & IFF_UP)
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 net *net = dev_net(skb->dev);
476 	u8 rel_type = ICMPV6_DEST_UNREACH;
477 	u8 rel_code = ICMPV6_ADDR_UNREACH;
478 	__u32 rel_info = 0;
479 	struct ip6_tnl *t;
480 	int err = -ENOENT;
481 	int rel_msg = 0;
482 	u8 tproto;
483 	__u16 len;
484 
485 	/* If the packet doesn't contain the original IPv6 header we are
486 	   in trouble since we might need the source address for further
487 	   processing of the error. */
488 
489 	rcu_read_lock();
490 	t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->daddr, &ipv6h->saddr);
491 	if (!t)
492 		goto out;
493 
494 	tproto = READ_ONCE(t->parms.proto);
495 	if (tproto != ipproto && tproto != 0)
496 		goto out;
497 
498 	err = 0;
499 
500 	switch (*type) {
501 		struct ipv6_tlv_tnl_enc_lim *tel;
502 		__u32 mtu, teli;
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 		ip6_update_pmtu(skb, net, htonl(*info), 0, 0,
534 				sock_net_uid(net, NULL));
535 		mtu = *info - offset;
536 		if (mtu < IPV6_MIN_MTU)
537 			mtu = IPV6_MIN_MTU;
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 	case NDISC_REDIRECT:
547 		ip6_redirect(skb, net, skb->dev->ifindex, 0,
548 			     sock_net_uid(net, NULL));
549 		break;
550 	}
551 
552 	*type = rel_type;
553 	*code = rel_code;
554 	*info = rel_info;
555 	*msg = rel_msg;
556 
557 out:
558 	rcu_read_unlock();
559 	return err;
560 }
561 
562 static int
563 ip4ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
564 	   u8 type, u8 code, int offset, __be32 info)
565 {
566 	__u32 rel_info = ntohl(info);
567 	const struct iphdr *eiph;
568 	struct sk_buff *skb2;
569 	int err, rel_msg = 0;
570 	u8 rel_type = type;
571 	u8 rel_code = code;
572 	struct rtable *rt;
573 	struct flowi4 fl4;
574 
575 	err = ip6_tnl_err(skb, IPPROTO_IPIP, opt, &rel_type, &rel_code,
576 			  &rel_msg, &rel_info, offset);
577 	if (err < 0)
578 		return err;
579 
580 	if (rel_msg == 0)
581 		return 0;
582 
583 	switch (rel_type) {
584 	case ICMPV6_DEST_UNREACH:
585 		if (rel_code != ICMPV6_ADDR_UNREACH)
586 			return 0;
587 		rel_type = ICMP_DEST_UNREACH;
588 		rel_code = ICMP_HOST_UNREACH;
589 		break;
590 	case ICMPV6_PKT_TOOBIG:
591 		if (rel_code != 0)
592 			return 0;
593 		rel_type = ICMP_DEST_UNREACH;
594 		rel_code = ICMP_FRAG_NEEDED;
595 		break;
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, eiph->saddr,
615 				   0, 0, 0, IPPROTO_IPIP, RT_TOS(eiph->tos), 0);
616 	if (IS_ERR(rt))
617 		goto out;
618 
619 	skb2->dev = rt->dst.dev;
620 	ip_rt_put(rt);
621 
622 	/* route "incoming" packet */
623 	if (rt->rt_flags & RTCF_LOCAL) {
624 		rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL,
625 					   eiph->daddr, eiph->saddr, 0, 0,
626 					   IPPROTO_IPIP, RT_TOS(eiph->tos), 0);
627 		if (IS_ERR(rt) || rt->dst.dev->type != ARPHRD_TUNNEL) {
628 			if (!IS_ERR(rt))
629 				ip_rt_put(rt);
630 			goto out;
631 		}
632 		skb_dst_set(skb2, &rt->dst);
633 	} else {
634 		if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos,
635 				   skb2->dev) ||
636 		    skb_dst(skb2)->dev->type != ARPHRD_TUNNEL)
637 			goto out;
638 	}
639 
640 	/* change mtu on this route */
641 	if (rel_type == ICMP_DEST_UNREACH && rel_code == ICMP_FRAG_NEEDED) {
642 		if (rel_info > dst_mtu(skb_dst(skb2)))
643 			goto out;
644 
645 		skb_dst(skb2)->ops->update_pmtu(skb_dst(skb2), NULL, skb2,
646 						rel_info);
647 	}
648 
649 	icmp_send(skb2, rel_type, rel_code, htonl(rel_info));
650 
651 out:
652 	kfree_skb(skb2);
653 	return 0;
654 }
655 
656 static int
657 ip6ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
658 	   u8 type, u8 code, int offset, __be32 info)
659 {
660 	__u32 rel_info = ntohl(info);
661 	int err, rel_msg = 0;
662 	u8 rel_type = type;
663 	u8 rel_code = code;
664 
665 	err = ip6_tnl_err(skb, IPPROTO_IPV6, opt, &rel_type, &rel_code,
666 			  &rel_msg, &rel_info, offset);
667 	if (err < 0)
668 		return err;
669 
670 	if (rel_msg && pskb_may_pull(skb, offset + sizeof(struct ipv6hdr))) {
671 		struct rt6_info *rt;
672 		struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
673 
674 		if (!skb2)
675 			return 0;
676 
677 		skb_dst_drop(skb2);
678 		skb_pull(skb2, offset);
679 		skb_reset_network_header(skb2);
680 
681 		/* Try to guess incoming interface */
682 		rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr,
683 				NULL, 0, 0);
684 
685 		if (rt && rt->dst.dev)
686 			skb2->dev = rt->dst.dev;
687 
688 		icmpv6_send(skb2, rel_type, rel_code, rel_info);
689 
690 		ip6_rt_put(rt);
691 
692 		kfree_skb(skb2);
693 	}
694 
695 	return 0;
696 }
697 
698 static int ip4ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
699 				       const struct ipv6hdr *ipv6h,
700 				       struct sk_buff *skb)
701 {
702 	__u8 dsfield = ipv6_get_dsfield(ipv6h) & ~INET_ECN_MASK;
703 
704 	if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
705 		ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, dsfield);
706 
707 	return IP6_ECN_decapsulate(ipv6h, skb);
708 }
709 
710 static int ip6ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
711 				       const struct ipv6hdr *ipv6h,
712 				       struct sk_buff *skb)
713 {
714 	if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
715 		ipv6_copy_dscp(ipv6_get_dsfield(ipv6h), ipv6_hdr(skb));
716 
717 	return IP6_ECN_decapsulate(ipv6h, skb);
718 }
719 
720 __u32 ip6_tnl_get_cap(struct ip6_tnl *t,
721 			     const struct in6_addr *laddr,
722 			     const struct in6_addr *raddr)
723 {
724 	struct __ip6_tnl_parm *p = &t->parms;
725 	int ltype = ipv6_addr_type(laddr);
726 	int rtype = ipv6_addr_type(raddr);
727 	__u32 flags = 0;
728 
729 	if (ltype == IPV6_ADDR_ANY || rtype == IPV6_ADDR_ANY) {
730 		flags = IP6_TNL_F_CAP_PER_PACKET;
731 	} else if (ltype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
732 		   rtype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
733 		   !((ltype|rtype) & IPV6_ADDR_LOOPBACK) &&
734 		   (!((ltype|rtype) & IPV6_ADDR_LINKLOCAL) || p->link)) {
735 		if (ltype&IPV6_ADDR_UNICAST)
736 			flags |= IP6_TNL_F_CAP_XMIT;
737 		if (rtype&IPV6_ADDR_UNICAST)
738 			flags |= IP6_TNL_F_CAP_RCV;
739 	}
740 	return flags;
741 }
742 EXPORT_SYMBOL(ip6_tnl_get_cap);
743 
744 /* called with rcu_read_lock() */
745 int ip6_tnl_rcv_ctl(struct ip6_tnl *t,
746 				  const struct in6_addr *laddr,
747 				  const struct in6_addr *raddr)
748 {
749 	struct __ip6_tnl_parm *p = &t->parms;
750 	int ret = 0;
751 	struct net *net = t->net;
752 
753 	if ((p->flags & IP6_TNL_F_CAP_RCV) ||
754 	    ((p->flags & IP6_TNL_F_CAP_PER_PACKET) &&
755 	     (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_RCV))) {
756 		struct net_device *ldev = NULL;
757 
758 		if (p->link)
759 			ldev = dev_get_by_index_rcu(net, p->link);
760 
761 		if ((ipv6_addr_is_multicast(laddr) ||
762 		     likely(ipv6_chk_addr(net, laddr, ldev, 0))) &&
763 		    ((p->flags & IP6_TNL_F_ALLOW_LOCAL_REMOTE) ||
764 		     likely(!ipv6_chk_addr(net, raddr, NULL, 0))))
765 			ret = 1;
766 	}
767 	return ret;
768 }
769 EXPORT_SYMBOL_GPL(ip6_tnl_rcv_ctl);
770 
771 static int __ip6_tnl_rcv(struct ip6_tnl *tunnel, struct sk_buff *skb,
772 			 const struct tnl_ptk_info *tpi,
773 			 struct metadata_dst *tun_dst,
774 			 int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
775 						const struct ipv6hdr *ipv6h,
776 						struct sk_buff *skb),
777 			 bool log_ecn_err)
778 {
779 	struct pcpu_sw_netstats *tstats;
780 	const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
781 	int err;
782 
783 	if ((!(tpi->flags & TUNNEL_CSUM) &&
784 	     (tunnel->parms.i_flags & TUNNEL_CSUM)) ||
785 	    ((tpi->flags & TUNNEL_CSUM) &&
786 	     !(tunnel->parms.i_flags & TUNNEL_CSUM))) {
787 		tunnel->dev->stats.rx_crc_errors++;
788 		tunnel->dev->stats.rx_errors++;
789 		goto drop;
790 	}
791 
792 	if (tunnel->parms.i_flags & TUNNEL_SEQ) {
793 		if (!(tpi->flags & TUNNEL_SEQ) ||
794 		    (tunnel->i_seqno &&
795 		     (s32)(ntohl(tpi->seq) - tunnel->i_seqno) < 0)) {
796 			tunnel->dev->stats.rx_fifo_errors++;
797 			tunnel->dev->stats.rx_errors++;
798 			goto drop;
799 		}
800 		tunnel->i_seqno = ntohl(tpi->seq) + 1;
801 	}
802 
803 	skb->protocol = tpi->proto;
804 
805 	/* Warning: All skb pointers will be invalidated! */
806 	if (tunnel->dev->type == ARPHRD_ETHER) {
807 		if (!pskb_may_pull(skb, ETH_HLEN)) {
808 			tunnel->dev->stats.rx_length_errors++;
809 			tunnel->dev->stats.rx_errors++;
810 			goto drop;
811 		}
812 
813 		ipv6h = ipv6_hdr(skb);
814 		skb->protocol = eth_type_trans(skb, tunnel->dev);
815 		skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
816 	} else {
817 		skb->dev = tunnel->dev;
818 	}
819 
820 	skb_reset_network_header(skb);
821 	memset(skb->cb, 0, sizeof(struct inet6_skb_parm));
822 
823 	__skb_tunnel_rx(skb, tunnel->dev, tunnel->net);
824 
825 	err = dscp_ecn_decapsulate(tunnel, ipv6h, skb);
826 	if (unlikely(err)) {
827 		if (log_ecn_err)
828 			net_info_ratelimited("non-ECT from %pI6 with DS=%#x\n",
829 					     &ipv6h->saddr,
830 					     ipv6_get_dsfield(ipv6h));
831 		if (err > 1) {
832 			++tunnel->dev->stats.rx_frame_errors;
833 			++tunnel->dev->stats.rx_errors;
834 			goto drop;
835 		}
836 	}
837 
838 	tstats = this_cpu_ptr(tunnel->dev->tstats);
839 	u64_stats_update_begin(&tstats->syncp);
840 	tstats->rx_packets++;
841 	tstats->rx_bytes += skb->len;
842 	u64_stats_update_end(&tstats->syncp);
843 
844 	skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(tunnel->dev)));
845 
846 	if (tun_dst)
847 		skb_dst_set(skb, (struct dst_entry *)tun_dst);
848 
849 	gro_cells_receive(&tunnel->gro_cells, skb);
850 	return 0;
851 
852 drop:
853 	if (tun_dst)
854 		dst_release((struct dst_entry *)tun_dst);
855 	kfree_skb(skb);
856 	return 0;
857 }
858 
859 int ip6_tnl_rcv(struct ip6_tnl *t, struct sk_buff *skb,
860 		const struct tnl_ptk_info *tpi,
861 		struct metadata_dst *tun_dst,
862 		bool log_ecn_err)
863 {
864 	return __ip6_tnl_rcv(t, skb, tpi, NULL, ip6ip6_dscp_ecn_decapsulate,
865 			     log_ecn_err);
866 }
867 EXPORT_SYMBOL(ip6_tnl_rcv);
868 
869 static const struct tnl_ptk_info tpi_v6 = {
870 	/* no tunnel info required for ipxip6. */
871 	.proto = htons(ETH_P_IPV6),
872 };
873 
874 static const struct tnl_ptk_info tpi_v4 = {
875 	/* no tunnel info required for ipxip6. */
876 	.proto = htons(ETH_P_IP),
877 };
878 
879 static int ipxip6_rcv(struct sk_buff *skb, u8 ipproto,
880 		      const struct tnl_ptk_info *tpi,
881 		      int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
882 						  const struct ipv6hdr *ipv6h,
883 						  struct sk_buff *skb))
884 {
885 	struct ip6_tnl *t;
886 	const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
887 	struct metadata_dst *tun_dst = NULL;
888 	int ret = -1;
889 
890 	rcu_read_lock();
891 	t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->saddr, &ipv6h->daddr);
892 
893 	if (t) {
894 		u8 tproto = READ_ONCE(t->parms.proto);
895 
896 		if (tproto != ipproto && tproto != 0)
897 			goto drop;
898 		if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
899 			goto drop;
900 		if (!ip6_tnl_rcv_ctl(t, &ipv6h->daddr, &ipv6h->saddr))
901 			goto drop;
902 		if (iptunnel_pull_header(skb, 0, tpi->proto, false))
903 			goto drop;
904 		if (t->parms.collect_md) {
905 			tun_dst = ipv6_tun_rx_dst(skb, 0, 0, 0);
906 			if (!tun_dst)
907 				return 0;
908 		}
909 		ret = __ip6_tnl_rcv(t, skb, tpi, tun_dst, dscp_ecn_decapsulate,
910 				    log_ecn_error);
911 	}
912 
913 	rcu_read_unlock();
914 
915 	return ret;
916 
917 drop:
918 	rcu_read_unlock();
919 	kfree_skb(skb);
920 	return 0;
921 }
922 
923 static int ip4ip6_rcv(struct sk_buff *skb)
924 {
925 	return ipxip6_rcv(skb, IPPROTO_IPIP, &tpi_v4,
926 			  ip4ip6_dscp_ecn_decapsulate);
927 }
928 
929 static int ip6ip6_rcv(struct sk_buff *skb)
930 {
931 	return ipxip6_rcv(skb, IPPROTO_IPV6, &tpi_v6,
932 			  ip6ip6_dscp_ecn_decapsulate);
933 }
934 
935 struct ipv6_tel_txoption {
936 	struct ipv6_txoptions ops;
937 	__u8 dst_opt[8];
938 };
939 
940 static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit)
941 {
942 	memset(opt, 0, sizeof(struct ipv6_tel_txoption));
943 
944 	opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT;
945 	opt->dst_opt[3] = 1;
946 	opt->dst_opt[4] = encap_limit;
947 	opt->dst_opt[5] = IPV6_TLV_PADN;
948 	opt->dst_opt[6] = 1;
949 
950 	opt->ops.dst1opt = (struct ipv6_opt_hdr *) opt->dst_opt;
951 	opt->ops.opt_nflen = 8;
952 }
953 
954 /**
955  * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
956  *   @t: the outgoing tunnel device
957  *   @hdr: IPv6 header from the incoming packet
958  *
959  * Description:
960  *   Avoid trivial tunneling loop by checking that tunnel exit-point
961  *   doesn't match source of incoming packet.
962  *
963  * Return:
964  *   1 if conflict,
965  *   0 else
966  **/
967 
968 static inline bool
969 ip6_tnl_addr_conflict(const struct ip6_tnl *t, const struct ipv6hdr *hdr)
970 {
971 	return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
972 }
973 
974 int ip6_tnl_xmit_ctl(struct ip6_tnl *t,
975 		     const struct in6_addr *laddr,
976 		     const struct in6_addr *raddr)
977 {
978 	struct __ip6_tnl_parm *p = &t->parms;
979 	int ret = 0;
980 	struct net *net = t->net;
981 
982 	if ((p->flags & IP6_TNL_F_CAP_XMIT) ||
983 	    ((p->flags & IP6_TNL_F_CAP_PER_PACKET) &&
984 	     (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_XMIT))) {
985 		struct net_device *ldev = NULL;
986 
987 		rcu_read_lock();
988 		if (p->link)
989 			ldev = dev_get_by_index_rcu(net, p->link);
990 
991 		if (unlikely(!ipv6_chk_addr(net, laddr, ldev, 0)))
992 			pr_warn("%s xmit: Local address not yet configured!\n",
993 				p->name);
994 		else if (!(p->flags & IP6_TNL_F_ALLOW_LOCAL_REMOTE) &&
995 			 !ipv6_addr_is_multicast(raddr) &&
996 			 unlikely(ipv6_chk_addr(net, raddr, NULL, 0)))
997 			pr_warn("%s xmit: Routing loop! Remote address found on this node!\n",
998 				p->name);
999 		else
1000 			ret = 1;
1001 		rcu_read_unlock();
1002 	}
1003 	return ret;
1004 }
1005 EXPORT_SYMBOL_GPL(ip6_tnl_xmit_ctl);
1006 
1007 /**
1008  * ip6_tnl_xmit - encapsulate packet and send
1009  *   @skb: the outgoing socket buffer
1010  *   @dev: the outgoing tunnel device
1011  *   @dsfield: dscp code for outer header
1012  *   @fl6: flow of tunneled packet
1013  *   @encap_limit: encapsulation limit
1014  *   @pmtu: Path MTU is stored if packet is too big
1015  *   @proto: next header value
1016  *
1017  * Description:
1018  *   Build new header and do some sanity checks on the packet before sending
1019  *   it.
1020  *
1021  * Return:
1022  *   0 on success
1023  *   -1 fail
1024  *   %-EMSGSIZE message too big. return mtu in this case.
1025  **/
1026 
1027 int ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev, __u8 dsfield,
1028 		 struct flowi6 *fl6, int encap_limit, __u32 *pmtu,
1029 		 __u8 proto)
1030 {
1031 	struct ip6_tnl *t = netdev_priv(dev);
1032 	struct net *net = t->net;
1033 	struct net_device_stats *stats = &t->dev->stats;
1034 	struct ipv6hdr *ipv6h;
1035 	struct ipv6_tel_txoption opt;
1036 	struct dst_entry *dst = NULL, *ndst = NULL;
1037 	struct net_device *tdev;
1038 	int mtu;
1039 	unsigned int eth_hlen = t->dev->type == ARPHRD_ETHER ? ETH_HLEN : 0;
1040 	unsigned int psh_hlen = sizeof(struct ipv6hdr) + t->encap_hlen;
1041 	unsigned int max_headroom = psh_hlen;
1042 	bool use_cache = false;
1043 	u8 hop_limit;
1044 	int err = -1;
1045 
1046 	if (t->parms.collect_md) {
1047 		hop_limit = skb_tunnel_info(skb)->key.ttl;
1048 		goto route_lookup;
1049 	} else {
1050 		hop_limit = t->parms.hop_limit;
1051 	}
1052 
1053 	/* NBMA tunnel */
1054 	if (ipv6_addr_any(&t->parms.raddr)) {
1055 		if (skb->protocol == htons(ETH_P_IPV6)) {
1056 			struct in6_addr *addr6;
1057 			struct neighbour *neigh;
1058 			int addr_type;
1059 
1060 			if (!skb_dst(skb))
1061 				goto tx_err_link_failure;
1062 
1063 			neigh = dst_neigh_lookup(skb_dst(skb),
1064 						 &ipv6_hdr(skb)->daddr);
1065 			if (!neigh)
1066 				goto tx_err_link_failure;
1067 
1068 			addr6 = (struct in6_addr *)&neigh->primary_key;
1069 			addr_type = ipv6_addr_type(addr6);
1070 
1071 			if (addr_type == IPV6_ADDR_ANY)
1072 				addr6 = &ipv6_hdr(skb)->daddr;
1073 
1074 			memcpy(&fl6->daddr, addr6, sizeof(fl6->daddr));
1075 			neigh_release(neigh);
1076 		}
1077 	} else if (!(t->parms.flags &
1078 		     (IP6_TNL_F_USE_ORIG_TCLASS | IP6_TNL_F_USE_ORIG_FWMARK))) {
1079 		/* enable the cache only only if the routing decision does
1080 		 * not depend on the current inner header value
1081 		 */
1082 		use_cache = true;
1083 	}
1084 
1085 	if (use_cache)
1086 		dst = dst_cache_get(&t->dst_cache);
1087 
1088 	if (!ip6_tnl_xmit_ctl(t, &fl6->saddr, &fl6->daddr))
1089 		goto tx_err_link_failure;
1090 
1091 	if (!dst) {
1092 route_lookup:
1093 		/* add dsfield to flowlabel for route lookup */
1094 		fl6->flowlabel = ip6_make_flowinfo(dsfield, fl6->flowlabel);
1095 
1096 		dst = ip6_route_output(net, NULL, fl6);
1097 
1098 		if (dst->error)
1099 			goto tx_err_link_failure;
1100 		dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), NULL, 0);
1101 		if (IS_ERR(dst)) {
1102 			err = PTR_ERR(dst);
1103 			dst = NULL;
1104 			goto tx_err_link_failure;
1105 		}
1106 		if (t->parms.collect_md &&
1107 		    ipv6_dev_get_saddr(net, ip6_dst_idev(dst)->dev,
1108 				       &fl6->daddr, 0, &fl6->saddr))
1109 			goto tx_err_link_failure;
1110 		ndst = dst;
1111 	}
1112 
1113 	tdev = dst->dev;
1114 
1115 	if (tdev == dev) {
1116 		stats->collisions++;
1117 		net_warn_ratelimited("%s: Local routing loop detected!\n",
1118 				     t->parms.name);
1119 		goto tx_err_dst_release;
1120 	}
1121 	mtu = dst_mtu(dst) - eth_hlen - psh_hlen - t->tun_hlen;
1122 	if (encap_limit >= 0) {
1123 		max_headroom += 8;
1124 		mtu -= 8;
1125 	}
1126 	if (mtu < IPV6_MIN_MTU)
1127 		mtu = IPV6_MIN_MTU;
1128 	if (skb_dst(skb) && !t->parms.collect_md)
1129 		skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
1130 	if (skb->len - t->tun_hlen - eth_hlen > mtu && !skb_is_gso(skb)) {
1131 		*pmtu = mtu;
1132 		err = -EMSGSIZE;
1133 		goto tx_err_dst_release;
1134 	}
1135 
1136 	if (t->err_count > 0) {
1137 		if (time_before(jiffies,
1138 				t->err_time + IP6TUNNEL_ERR_TIMEO)) {
1139 			t->err_count--;
1140 
1141 			dst_link_failure(skb);
1142 		} else {
1143 			t->err_count = 0;
1144 		}
1145 	}
1146 
1147 	skb_scrub_packet(skb, !net_eq(t->net, dev_net(dev)));
1148 
1149 	/*
1150 	 * Okay, now see if we can stuff it in the buffer as-is.
1151 	 */
1152 	max_headroom += LL_RESERVED_SPACE(tdev);
1153 
1154 	if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
1155 	    (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
1156 		struct sk_buff *new_skb;
1157 
1158 		new_skb = skb_realloc_headroom(skb, max_headroom);
1159 		if (!new_skb)
1160 			goto tx_err_dst_release;
1161 
1162 		if (skb->sk)
1163 			skb_set_owner_w(new_skb, skb->sk);
1164 		consume_skb(skb);
1165 		skb = new_skb;
1166 	}
1167 
1168 	if (t->parms.collect_md) {
1169 		if (t->encap.type != TUNNEL_ENCAP_NONE)
1170 			goto tx_err_dst_release;
1171 	} else {
1172 		if (use_cache && ndst)
1173 			dst_cache_set_ip6(&t->dst_cache, ndst, &fl6->saddr);
1174 	}
1175 	skb_dst_set(skb, dst);
1176 
1177 	if (encap_limit >= 0) {
1178 		init_tel_txopt(&opt, encap_limit);
1179 		ipv6_push_frag_opts(skb, &opt.ops, &proto);
1180 	}
1181 	hop_limit = hop_limit ? : ip6_dst_hoplimit(dst);
1182 
1183 	/* Calculate max headroom for all the headers and adjust
1184 	 * needed_headroom if necessary.
1185 	 */
1186 	max_headroom = LL_RESERVED_SPACE(dst->dev) + sizeof(struct ipv6hdr)
1187 			+ dst->header_len + t->hlen;
1188 	if (max_headroom > dev->needed_headroom)
1189 		dev->needed_headroom = max_headroom;
1190 
1191 	err = ip6_tnl_encap(skb, t, &proto, fl6);
1192 	if (err)
1193 		return err;
1194 
1195 	skb_push(skb, sizeof(struct ipv6hdr));
1196 	skb_reset_network_header(skb);
1197 	ipv6h = ipv6_hdr(skb);
1198 	ip6_flow_hdr(ipv6h, dsfield,
1199 		     ip6_make_flowlabel(net, skb, fl6->flowlabel, true, fl6));
1200 	ipv6h->hop_limit = hop_limit;
1201 	ipv6h->nexthdr = proto;
1202 	ipv6h->saddr = fl6->saddr;
1203 	ipv6h->daddr = fl6->daddr;
1204 	ip6tunnel_xmit(NULL, skb, dev);
1205 	return 0;
1206 tx_err_link_failure:
1207 	stats->tx_carrier_errors++;
1208 	dst_link_failure(skb);
1209 tx_err_dst_release:
1210 	dst_release(dst);
1211 	return err;
1212 }
1213 EXPORT_SYMBOL(ip6_tnl_xmit);
1214 
1215 static inline int
1216 ip4ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1217 {
1218 	struct ip6_tnl *t = netdev_priv(dev);
1219 	const struct iphdr  *iph = ip_hdr(skb);
1220 	int encap_limit = -1;
1221 	struct flowi6 fl6;
1222 	__u8 dsfield;
1223 	__u32 mtu;
1224 	u8 tproto;
1225 	int err;
1226 
1227 	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1228 
1229 	tproto = READ_ONCE(t->parms.proto);
1230 	if (tproto != IPPROTO_IPIP && tproto != 0)
1231 		return -1;
1232 
1233 	if (t->parms.collect_md) {
1234 		struct ip_tunnel_info *tun_info;
1235 		const struct ip_tunnel_key *key;
1236 
1237 		tun_info = skb_tunnel_info(skb);
1238 		if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
1239 			     ip_tunnel_info_af(tun_info) != AF_INET6))
1240 			return -1;
1241 		key = &tun_info->key;
1242 		memset(&fl6, 0, sizeof(fl6));
1243 		fl6.flowi6_proto = IPPROTO_IPIP;
1244 		fl6.daddr = key->u.ipv6.dst;
1245 		fl6.flowlabel = key->label;
1246 		dsfield =  key->tos;
1247 	} else {
1248 		if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1249 			encap_limit = t->parms.encap_limit;
1250 
1251 		memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
1252 		fl6.flowi6_proto = IPPROTO_IPIP;
1253 
1254 		if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1255 			dsfield = ipv4_get_dsfield(iph);
1256 		else
1257 			dsfield = ip6_tclass(t->parms.flowinfo);
1258 		if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
1259 			fl6.flowi6_mark = skb->mark;
1260 		else
1261 			fl6.flowi6_mark = t->parms.fwmark;
1262 	}
1263 
1264 	fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
1265 
1266 	if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP6))
1267 		return -1;
1268 
1269 	dsfield = INET_ECN_encapsulate(dsfield, ipv4_get_dsfield(iph));
1270 
1271 	skb_set_inner_ipproto(skb, IPPROTO_IPIP);
1272 
1273 	err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
1274 			   IPPROTO_IPIP);
1275 	if (err != 0) {
1276 		/* XXX: send ICMP error even if DF is not set. */
1277 		if (err == -EMSGSIZE)
1278 			icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
1279 				  htonl(mtu));
1280 		return -1;
1281 	}
1282 
1283 	return 0;
1284 }
1285 
1286 static inline int
1287 ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1288 {
1289 	struct ip6_tnl *t = netdev_priv(dev);
1290 	struct ipv6hdr *ipv6h = ipv6_hdr(skb);
1291 	int encap_limit = -1;
1292 	__u16 offset;
1293 	struct flowi6 fl6;
1294 	__u8 dsfield;
1295 	__u32 mtu;
1296 	u8 tproto;
1297 	int err;
1298 
1299 	tproto = READ_ONCE(t->parms.proto);
1300 	if ((tproto != IPPROTO_IPV6 && tproto != 0) ||
1301 	    ip6_tnl_addr_conflict(t, ipv6h))
1302 		return -1;
1303 
1304 	if (t->parms.collect_md) {
1305 		struct ip_tunnel_info *tun_info;
1306 		const struct ip_tunnel_key *key;
1307 
1308 		tun_info = skb_tunnel_info(skb);
1309 		if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
1310 			     ip_tunnel_info_af(tun_info) != AF_INET6))
1311 			return -1;
1312 		key = &tun_info->key;
1313 		memset(&fl6, 0, sizeof(fl6));
1314 		fl6.flowi6_proto = IPPROTO_IPV6;
1315 		fl6.daddr = key->u.ipv6.dst;
1316 		fl6.flowlabel = key->label;
1317 		dsfield = key->tos;
1318 	} else {
1319 		offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
1320 		/* ip6_tnl_parse_tlv_enc_lim() might have reallocated skb->head */
1321 		ipv6h = ipv6_hdr(skb);
1322 		if (offset > 0) {
1323 			struct ipv6_tlv_tnl_enc_lim *tel;
1324 
1325 			tel = (void *)&skb_network_header(skb)[offset];
1326 			if (tel->encap_limit == 0) {
1327 				icmpv6_send(skb, ICMPV6_PARAMPROB,
1328 					    ICMPV6_HDR_FIELD, offset + 2);
1329 				return -1;
1330 			}
1331 			encap_limit = tel->encap_limit - 1;
1332 		} else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) {
1333 			encap_limit = t->parms.encap_limit;
1334 		}
1335 
1336 		memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
1337 		fl6.flowi6_proto = IPPROTO_IPV6;
1338 
1339 		if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1340 			dsfield = ipv6_get_dsfield(ipv6h);
1341 		else
1342 			dsfield = ip6_tclass(t->parms.flowinfo);
1343 		if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
1344 			fl6.flowlabel |= ip6_flowlabel(ipv6h);
1345 		if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
1346 			fl6.flowi6_mark = skb->mark;
1347 		else
1348 			fl6.flowi6_mark = t->parms.fwmark;
1349 	}
1350 
1351 	fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
1352 
1353 	if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP6))
1354 		return -1;
1355 
1356 	dsfield = INET_ECN_encapsulate(dsfield, ipv6_get_dsfield(ipv6h));
1357 
1358 	skb_set_inner_ipproto(skb, IPPROTO_IPV6);
1359 
1360 	err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
1361 			   IPPROTO_IPV6);
1362 	if (err != 0) {
1363 		if (err == -EMSGSIZE)
1364 			icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
1365 		return -1;
1366 	}
1367 
1368 	return 0;
1369 }
1370 
1371 static netdev_tx_t
1372 ip6_tnl_start_xmit(struct sk_buff *skb, struct net_device *dev)
1373 {
1374 	struct ip6_tnl *t = netdev_priv(dev);
1375 	struct net_device_stats *stats = &t->dev->stats;
1376 	int ret;
1377 
1378 	switch (skb->protocol) {
1379 	case htons(ETH_P_IP):
1380 		ret = ip4ip6_tnl_xmit(skb, dev);
1381 		break;
1382 	case htons(ETH_P_IPV6):
1383 		ret = ip6ip6_tnl_xmit(skb, dev);
1384 		break;
1385 	default:
1386 		goto tx_err;
1387 	}
1388 
1389 	if (ret < 0)
1390 		goto tx_err;
1391 
1392 	return NETDEV_TX_OK;
1393 
1394 tx_err:
1395 	stats->tx_errors++;
1396 	stats->tx_dropped++;
1397 	kfree_skb(skb);
1398 	return NETDEV_TX_OK;
1399 }
1400 
1401 static void ip6_tnl_link_config(struct ip6_tnl *t)
1402 {
1403 	struct net_device *dev = t->dev;
1404 	struct __ip6_tnl_parm *p = &t->parms;
1405 	struct flowi6 *fl6 = &t->fl.u.ip6;
1406 	int t_hlen;
1407 
1408 	memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
1409 	memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
1410 
1411 	/* Set up flowi template */
1412 	fl6->saddr = p->laddr;
1413 	fl6->daddr = p->raddr;
1414 	fl6->flowi6_oif = p->link;
1415 	fl6->flowlabel = 0;
1416 
1417 	if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
1418 		fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
1419 	if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
1420 		fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
1421 
1422 	p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
1423 	p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
1424 
1425 	if (p->flags&IP6_TNL_F_CAP_XMIT && p->flags&IP6_TNL_F_CAP_RCV)
1426 		dev->flags |= IFF_POINTOPOINT;
1427 	else
1428 		dev->flags &= ~IFF_POINTOPOINT;
1429 
1430 	t->tun_hlen = 0;
1431 	t->hlen = t->encap_hlen + t->tun_hlen;
1432 	t_hlen = t->hlen + sizeof(struct ipv6hdr);
1433 
1434 	if (p->flags & IP6_TNL_F_CAP_XMIT) {
1435 		int strict = (ipv6_addr_type(&p->raddr) &
1436 			      (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
1437 
1438 		struct rt6_info *rt = rt6_lookup(t->net,
1439 						 &p->raddr, &p->laddr,
1440 						 p->link, strict);
1441 
1442 		if (!rt)
1443 			return;
1444 
1445 		if (rt->dst.dev) {
1446 			dev->hard_header_len = rt->dst.dev->hard_header_len +
1447 				t_hlen;
1448 
1449 			dev->mtu = rt->dst.dev->mtu - t_hlen;
1450 			if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1451 				dev->mtu -= 8;
1452 
1453 			if (dev->mtu < IPV6_MIN_MTU)
1454 				dev->mtu = IPV6_MIN_MTU;
1455 		}
1456 		ip6_rt_put(rt);
1457 	}
1458 }
1459 
1460 /**
1461  * ip6_tnl_change - update the tunnel parameters
1462  *   @t: tunnel to be changed
1463  *   @p: tunnel configuration parameters
1464  *
1465  * Description:
1466  *   ip6_tnl_change() updates the tunnel parameters
1467  **/
1468 
1469 static int
1470 ip6_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p)
1471 {
1472 	t->parms.laddr = p->laddr;
1473 	t->parms.raddr = p->raddr;
1474 	t->parms.flags = p->flags;
1475 	t->parms.hop_limit = p->hop_limit;
1476 	t->parms.encap_limit = p->encap_limit;
1477 	t->parms.flowinfo = p->flowinfo;
1478 	t->parms.link = p->link;
1479 	t->parms.proto = p->proto;
1480 	t->parms.fwmark = p->fwmark;
1481 	dst_cache_reset(&t->dst_cache);
1482 	ip6_tnl_link_config(t);
1483 	return 0;
1484 }
1485 
1486 static int ip6_tnl_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
1487 {
1488 	struct net *net = t->net;
1489 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1490 	int err;
1491 
1492 	ip6_tnl_unlink(ip6n, t);
1493 	synchronize_net();
1494 	err = ip6_tnl_change(t, p);
1495 	ip6_tnl_link(ip6n, t);
1496 	netdev_state_change(t->dev);
1497 	return err;
1498 }
1499 
1500 static int ip6_tnl0_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
1501 {
1502 	/* for default tnl0 device allow to change only the proto */
1503 	t->parms.proto = p->proto;
1504 	netdev_state_change(t->dev);
1505 	return 0;
1506 }
1507 
1508 static void
1509 ip6_tnl_parm_from_user(struct __ip6_tnl_parm *p, const struct ip6_tnl_parm *u)
1510 {
1511 	p->laddr = u->laddr;
1512 	p->raddr = u->raddr;
1513 	p->flags = u->flags;
1514 	p->hop_limit = u->hop_limit;
1515 	p->encap_limit = u->encap_limit;
1516 	p->flowinfo = u->flowinfo;
1517 	p->link = u->link;
1518 	p->proto = u->proto;
1519 	memcpy(p->name, u->name, sizeof(u->name));
1520 }
1521 
1522 static void
1523 ip6_tnl_parm_to_user(struct ip6_tnl_parm *u, const struct __ip6_tnl_parm *p)
1524 {
1525 	u->laddr = p->laddr;
1526 	u->raddr = p->raddr;
1527 	u->flags = p->flags;
1528 	u->hop_limit = p->hop_limit;
1529 	u->encap_limit = p->encap_limit;
1530 	u->flowinfo = p->flowinfo;
1531 	u->link = p->link;
1532 	u->proto = p->proto;
1533 	memcpy(u->name, p->name, sizeof(u->name));
1534 }
1535 
1536 /**
1537  * ip6_tnl_ioctl - configure ipv6 tunnels from userspace
1538  *   @dev: virtual device associated with tunnel
1539  *   @ifr: parameters passed from userspace
1540  *   @cmd: command to be performed
1541  *
1542  * Description:
1543  *   ip6_tnl_ioctl() is used for managing IPv6 tunnels
1544  *   from userspace.
1545  *
1546  *   The possible commands are the following:
1547  *     %SIOCGETTUNNEL: get tunnel parameters for device
1548  *     %SIOCADDTUNNEL: add tunnel matching given tunnel parameters
1549  *     %SIOCCHGTUNNEL: change tunnel parameters to those given
1550  *     %SIOCDELTUNNEL: delete tunnel
1551  *
1552  *   The fallback device "ip6tnl0", created during module
1553  *   initialization, can be used for creating other tunnel devices.
1554  *
1555  * Return:
1556  *   0 on success,
1557  *   %-EFAULT if unable to copy data to or from userspace,
1558  *   %-EPERM if current process hasn't %CAP_NET_ADMIN set
1559  *   %-EINVAL if passed tunnel parameters are invalid,
1560  *   %-EEXIST if changing a tunnel's parameters would cause a conflict
1561  *   %-ENODEV if attempting to change or delete a nonexisting device
1562  **/
1563 
1564 static int
1565 ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1566 {
1567 	int err = 0;
1568 	struct ip6_tnl_parm p;
1569 	struct __ip6_tnl_parm p1;
1570 	struct ip6_tnl *t = netdev_priv(dev);
1571 	struct net *net = t->net;
1572 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1573 
1574 	memset(&p1, 0, sizeof(p1));
1575 
1576 	switch (cmd) {
1577 	case SIOCGETTUNNEL:
1578 		if (dev == ip6n->fb_tnl_dev) {
1579 			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1580 				err = -EFAULT;
1581 				break;
1582 			}
1583 			ip6_tnl_parm_from_user(&p1, &p);
1584 			t = ip6_tnl_locate(net, &p1, 0);
1585 			if (IS_ERR(t))
1586 				t = netdev_priv(dev);
1587 		} else {
1588 			memset(&p, 0, sizeof(p));
1589 		}
1590 		ip6_tnl_parm_to_user(&p, &t->parms);
1591 		if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) {
1592 			err = -EFAULT;
1593 		}
1594 		break;
1595 	case SIOCADDTUNNEL:
1596 	case SIOCCHGTUNNEL:
1597 		err = -EPERM;
1598 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1599 			break;
1600 		err = -EFAULT;
1601 		if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1602 			break;
1603 		err = -EINVAL;
1604 		if (p.proto != IPPROTO_IPV6 && p.proto != IPPROTO_IPIP &&
1605 		    p.proto != 0)
1606 			break;
1607 		ip6_tnl_parm_from_user(&p1, &p);
1608 		t = ip6_tnl_locate(net, &p1, cmd == SIOCADDTUNNEL);
1609 		if (cmd == SIOCCHGTUNNEL) {
1610 			if (!IS_ERR(t)) {
1611 				if (t->dev != dev) {
1612 					err = -EEXIST;
1613 					break;
1614 				}
1615 			} else
1616 				t = netdev_priv(dev);
1617 			if (dev == ip6n->fb_tnl_dev)
1618 				err = ip6_tnl0_update(t, &p1);
1619 			else
1620 				err = ip6_tnl_update(t, &p1);
1621 		}
1622 		if (!IS_ERR(t)) {
1623 			err = 0;
1624 			ip6_tnl_parm_to_user(&p, &t->parms);
1625 			if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1626 				err = -EFAULT;
1627 
1628 		} else {
1629 			err = PTR_ERR(t);
1630 		}
1631 		break;
1632 	case SIOCDELTUNNEL:
1633 		err = -EPERM;
1634 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1635 			break;
1636 
1637 		if (dev == ip6n->fb_tnl_dev) {
1638 			err = -EFAULT;
1639 			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1640 				break;
1641 			err = -ENOENT;
1642 			ip6_tnl_parm_from_user(&p1, &p);
1643 			t = ip6_tnl_locate(net, &p1, 0);
1644 			if (IS_ERR(t))
1645 				break;
1646 			err = -EPERM;
1647 			if (t->dev == ip6n->fb_tnl_dev)
1648 				break;
1649 			dev = t->dev;
1650 		}
1651 		err = 0;
1652 		unregister_netdevice(dev);
1653 		break;
1654 	default:
1655 		err = -EINVAL;
1656 	}
1657 	return err;
1658 }
1659 
1660 /**
1661  * ip6_tnl_change_mtu - change mtu manually for tunnel device
1662  *   @dev: virtual device associated with tunnel
1663  *   @new_mtu: the new mtu
1664  *
1665  * Return:
1666  *   0 on success,
1667  *   %-EINVAL if mtu too small
1668  **/
1669 
1670 int ip6_tnl_change_mtu(struct net_device *dev, int new_mtu)
1671 {
1672 	struct ip6_tnl *tnl = netdev_priv(dev);
1673 
1674 	if (tnl->parms.proto == IPPROTO_IPIP) {
1675 		if (new_mtu < ETH_MIN_MTU)
1676 			return -EINVAL;
1677 	} else {
1678 		if (new_mtu < IPV6_MIN_MTU)
1679 			return -EINVAL;
1680 	}
1681 	if (new_mtu > 0xFFF8 - dev->hard_header_len)
1682 		return -EINVAL;
1683 	dev->mtu = new_mtu;
1684 	return 0;
1685 }
1686 EXPORT_SYMBOL(ip6_tnl_change_mtu);
1687 
1688 int ip6_tnl_get_iflink(const struct net_device *dev)
1689 {
1690 	struct ip6_tnl *t = netdev_priv(dev);
1691 
1692 	return t->parms.link;
1693 }
1694 EXPORT_SYMBOL(ip6_tnl_get_iflink);
1695 
1696 int ip6_tnl_encap_add_ops(const struct ip6_tnl_encap_ops *ops,
1697 			  unsigned int num)
1698 {
1699 	if (num >= MAX_IPTUN_ENCAP_OPS)
1700 		return -ERANGE;
1701 
1702 	return !cmpxchg((const struct ip6_tnl_encap_ops **)
1703 			&ip6tun_encaps[num],
1704 			NULL, ops) ? 0 : -1;
1705 }
1706 EXPORT_SYMBOL(ip6_tnl_encap_add_ops);
1707 
1708 int ip6_tnl_encap_del_ops(const struct ip6_tnl_encap_ops *ops,
1709 			  unsigned int num)
1710 {
1711 	int ret;
1712 
1713 	if (num >= MAX_IPTUN_ENCAP_OPS)
1714 		return -ERANGE;
1715 
1716 	ret = (cmpxchg((const struct ip6_tnl_encap_ops **)
1717 		       &ip6tun_encaps[num],
1718 		       ops, NULL) == ops) ? 0 : -1;
1719 
1720 	synchronize_net();
1721 
1722 	return ret;
1723 }
1724 EXPORT_SYMBOL(ip6_tnl_encap_del_ops);
1725 
1726 int ip6_tnl_encap_setup(struct ip6_tnl *t,
1727 			struct ip_tunnel_encap *ipencap)
1728 {
1729 	int hlen;
1730 
1731 	memset(&t->encap, 0, sizeof(t->encap));
1732 
1733 	hlen = ip6_encap_hlen(ipencap);
1734 	if (hlen < 0)
1735 		return hlen;
1736 
1737 	t->encap.type = ipencap->type;
1738 	t->encap.sport = ipencap->sport;
1739 	t->encap.dport = ipencap->dport;
1740 	t->encap.flags = ipencap->flags;
1741 
1742 	t->encap_hlen = hlen;
1743 	t->hlen = t->encap_hlen + t->tun_hlen;
1744 
1745 	return 0;
1746 }
1747 EXPORT_SYMBOL_GPL(ip6_tnl_encap_setup);
1748 
1749 static const struct net_device_ops ip6_tnl_netdev_ops = {
1750 	.ndo_init	= ip6_tnl_dev_init,
1751 	.ndo_uninit	= ip6_tnl_dev_uninit,
1752 	.ndo_start_xmit = ip6_tnl_start_xmit,
1753 	.ndo_do_ioctl	= ip6_tnl_ioctl,
1754 	.ndo_change_mtu = ip6_tnl_change_mtu,
1755 	.ndo_get_stats	= ip6_get_stats,
1756 	.ndo_get_iflink = ip6_tnl_get_iflink,
1757 };
1758 
1759 #define IPXIPX_FEATURES (NETIF_F_SG |		\
1760 			 NETIF_F_FRAGLIST |	\
1761 			 NETIF_F_HIGHDMA |	\
1762 			 NETIF_F_GSO_SOFTWARE |	\
1763 			 NETIF_F_HW_CSUM)
1764 
1765 /**
1766  * ip6_tnl_dev_setup - setup virtual tunnel device
1767  *   @dev: virtual device associated with tunnel
1768  *
1769  * Description:
1770  *   Initialize function pointers and device parameters
1771  **/
1772 
1773 static void ip6_tnl_dev_setup(struct net_device *dev)
1774 {
1775 	dev->netdev_ops = &ip6_tnl_netdev_ops;
1776 	dev->needs_free_netdev = true;
1777 	dev->priv_destructor = ip6_dev_free;
1778 
1779 	dev->type = ARPHRD_TUNNEL6;
1780 	dev->flags |= IFF_NOARP;
1781 	dev->addr_len = sizeof(struct in6_addr);
1782 	dev->features |= NETIF_F_LLTX;
1783 	netif_keep_dst(dev);
1784 
1785 	dev->features		|= IPXIPX_FEATURES;
1786 	dev->hw_features	|= IPXIPX_FEATURES;
1787 
1788 	/* This perm addr will be used as interface identifier by IPv6 */
1789 	dev->addr_assign_type = NET_ADDR_RANDOM;
1790 	eth_random_addr(dev->perm_addr);
1791 }
1792 
1793 
1794 /**
1795  * ip6_tnl_dev_init_gen - general initializer for all tunnel devices
1796  *   @dev: virtual device associated with tunnel
1797  **/
1798 
1799 static inline int
1800 ip6_tnl_dev_init_gen(struct net_device *dev)
1801 {
1802 	struct ip6_tnl *t = netdev_priv(dev);
1803 	int ret;
1804 	int t_hlen;
1805 
1806 	t->dev = dev;
1807 	t->net = dev_net(dev);
1808 	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1809 	if (!dev->tstats)
1810 		return -ENOMEM;
1811 
1812 	ret = dst_cache_init(&t->dst_cache, GFP_KERNEL);
1813 	if (ret)
1814 		goto free_stats;
1815 
1816 	ret = gro_cells_init(&t->gro_cells, dev);
1817 	if (ret)
1818 		goto destroy_dst;
1819 
1820 	t->tun_hlen = 0;
1821 	t->hlen = t->encap_hlen + t->tun_hlen;
1822 	t_hlen = t->hlen + sizeof(struct ipv6hdr);
1823 
1824 	dev->type = ARPHRD_TUNNEL6;
1825 	dev->hard_header_len = LL_MAX_HEADER + t_hlen;
1826 	dev->mtu = ETH_DATA_LEN - t_hlen;
1827 	if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1828 		dev->mtu -= 8;
1829 	dev->min_mtu = ETH_MIN_MTU;
1830 	dev->max_mtu = 0xFFF8 - dev->hard_header_len;
1831 
1832 	return 0;
1833 
1834 destroy_dst:
1835 	dst_cache_destroy(&t->dst_cache);
1836 free_stats:
1837 	free_percpu(dev->tstats);
1838 	dev->tstats = NULL;
1839 
1840 	return ret;
1841 }
1842 
1843 /**
1844  * ip6_tnl_dev_init - initializer for all non fallback tunnel devices
1845  *   @dev: virtual device associated with tunnel
1846  **/
1847 
1848 static int ip6_tnl_dev_init(struct net_device *dev)
1849 {
1850 	struct ip6_tnl *t = netdev_priv(dev);
1851 	int err = ip6_tnl_dev_init_gen(dev);
1852 
1853 	if (err)
1854 		return err;
1855 	ip6_tnl_link_config(t);
1856 	if (t->parms.collect_md) {
1857 		dev->features |= NETIF_F_NETNS_LOCAL;
1858 		netif_keep_dst(dev);
1859 	}
1860 	return 0;
1861 }
1862 
1863 /**
1864  * ip6_fb_tnl_dev_init - initializer for fallback tunnel device
1865  *   @dev: fallback device
1866  *
1867  * Return: 0
1868  **/
1869 
1870 static int __net_init ip6_fb_tnl_dev_init(struct net_device *dev)
1871 {
1872 	struct ip6_tnl *t = netdev_priv(dev);
1873 	struct net *net = dev_net(dev);
1874 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1875 
1876 	t->parms.proto = IPPROTO_IPV6;
1877 	dev_hold(dev);
1878 
1879 	rcu_assign_pointer(ip6n->tnls_wc[0], t);
1880 	return 0;
1881 }
1882 
1883 static int ip6_tnl_validate(struct nlattr *tb[], struct nlattr *data[],
1884 			    struct netlink_ext_ack *extack)
1885 {
1886 	u8 proto;
1887 
1888 	if (!data || !data[IFLA_IPTUN_PROTO])
1889 		return 0;
1890 
1891 	proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1892 	if (proto != IPPROTO_IPV6 &&
1893 	    proto != IPPROTO_IPIP &&
1894 	    proto != 0)
1895 		return -EINVAL;
1896 
1897 	return 0;
1898 }
1899 
1900 static void ip6_tnl_netlink_parms(struct nlattr *data[],
1901 				  struct __ip6_tnl_parm *parms)
1902 {
1903 	memset(parms, 0, sizeof(*parms));
1904 
1905 	if (!data)
1906 		return;
1907 
1908 	if (data[IFLA_IPTUN_LINK])
1909 		parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
1910 
1911 	if (data[IFLA_IPTUN_LOCAL])
1912 		parms->laddr = nla_get_in6_addr(data[IFLA_IPTUN_LOCAL]);
1913 
1914 	if (data[IFLA_IPTUN_REMOTE])
1915 		parms->raddr = nla_get_in6_addr(data[IFLA_IPTUN_REMOTE]);
1916 
1917 	if (data[IFLA_IPTUN_TTL])
1918 		parms->hop_limit = nla_get_u8(data[IFLA_IPTUN_TTL]);
1919 
1920 	if (data[IFLA_IPTUN_ENCAP_LIMIT])
1921 		parms->encap_limit = nla_get_u8(data[IFLA_IPTUN_ENCAP_LIMIT]);
1922 
1923 	if (data[IFLA_IPTUN_FLOWINFO])
1924 		parms->flowinfo = nla_get_be32(data[IFLA_IPTUN_FLOWINFO]);
1925 
1926 	if (data[IFLA_IPTUN_FLAGS])
1927 		parms->flags = nla_get_u32(data[IFLA_IPTUN_FLAGS]);
1928 
1929 	if (data[IFLA_IPTUN_PROTO])
1930 		parms->proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1931 
1932 	if (data[IFLA_IPTUN_COLLECT_METADATA])
1933 		parms->collect_md = true;
1934 
1935 	if (data[IFLA_IPTUN_FWMARK])
1936 		parms->fwmark = nla_get_u32(data[IFLA_IPTUN_FWMARK]);
1937 }
1938 
1939 static bool ip6_tnl_netlink_encap_parms(struct nlattr *data[],
1940 					struct ip_tunnel_encap *ipencap)
1941 {
1942 	bool ret = false;
1943 
1944 	memset(ipencap, 0, sizeof(*ipencap));
1945 
1946 	if (!data)
1947 		return ret;
1948 
1949 	if (data[IFLA_IPTUN_ENCAP_TYPE]) {
1950 		ret = true;
1951 		ipencap->type = nla_get_u16(data[IFLA_IPTUN_ENCAP_TYPE]);
1952 	}
1953 
1954 	if (data[IFLA_IPTUN_ENCAP_FLAGS]) {
1955 		ret = true;
1956 		ipencap->flags = nla_get_u16(data[IFLA_IPTUN_ENCAP_FLAGS]);
1957 	}
1958 
1959 	if (data[IFLA_IPTUN_ENCAP_SPORT]) {
1960 		ret = true;
1961 		ipencap->sport = nla_get_be16(data[IFLA_IPTUN_ENCAP_SPORT]);
1962 	}
1963 
1964 	if (data[IFLA_IPTUN_ENCAP_DPORT]) {
1965 		ret = true;
1966 		ipencap->dport = nla_get_be16(data[IFLA_IPTUN_ENCAP_DPORT]);
1967 	}
1968 
1969 	return ret;
1970 }
1971 
1972 static int ip6_tnl_newlink(struct net *src_net, struct net_device *dev,
1973 			   struct nlattr *tb[], struct nlattr *data[],
1974 			   struct netlink_ext_ack *extack)
1975 {
1976 	struct net *net = dev_net(dev);
1977 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1978 	struct ip6_tnl *nt, *t;
1979 	struct ip_tunnel_encap ipencap;
1980 
1981 	nt = netdev_priv(dev);
1982 
1983 	if (ip6_tnl_netlink_encap_parms(data, &ipencap)) {
1984 		int err = ip6_tnl_encap_setup(nt, &ipencap);
1985 
1986 		if (err < 0)
1987 			return err;
1988 	}
1989 
1990 	ip6_tnl_netlink_parms(data, &nt->parms);
1991 
1992 	if (nt->parms.collect_md) {
1993 		if (rtnl_dereference(ip6n->collect_md_tun))
1994 			return -EEXIST;
1995 	} else {
1996 		t = ip6_tnl_locate(net, &nt->parms, 0);
1997 		if (!IS_ERR(t))
1998 			return -EEXIST;
1999 	}
2000 
2001 	return ip6_tnl_create2(dev);
2002 }
2003 
2004 static int ip6_tnl_changelink(struct net_device *dev, struct nlattr *tb[],
2005 			      struct nlattr *data[],
2006 			      struct netlink_ext_ack *extack)
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, struct list_head *list)
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 
2171 	for_each_netdev_safe(net, dev, aux)
2172 		if (dev->rtnl_link_ops == &ip6_link_ops)
2173 			unregister_netdevice_queue(dev, list);
2174 
2175 	for (h = 0; h < IP6_TUNNEL_HASH_SIZE; h++) {
2176 		t = rtnl_dereference(ip6n->tnls_r_l[h]);
2177 		while (t) {
2178 			/* If dev is in the same netns, it has already
2179 			 * been added to the list by the previous loop.
2180 			 */
2181 			if (!net_eq(dev_net(t->dev), net))
2182 				unregister_netdevice_queue(t->dev, list);
2183 			t = rtnl_dereference(t->next);
2184 		}
2185 	}
2186 }
2187 
2188 static int __net_init ip6_tnl_init_net(struct net *net)
2189 {
2190 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2191 	struct ip6_tnl *t = NULL;
2192 	int err;
2193 
2194 	ip6n->tnls[0] = ip6n->tnls_wc;
2195 	ip6n->tnls[1] = ip6n->tnls_r_l;
2196 
2197 	err = -ENOMEM;
2198 	ip6n->fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6tnl0",
2199 					NET_NAME_UNKNOWN, ip6_tnl_dev_setup);
2200 
2201 	if (!ip6n->fb_tnl_dev)
2202 		goto err_alloc_dev;
2203 	dev_net_set(ip6n->fb_tnl_dev, net);
2204 	ip6n->fb_tnl_dev->rtnl_link_ops = &ip6_link_ops;
2205 	/* FB netdevice is special: we have one, and only one per netns.
2206 	 * Allowing to move it to another netns is clearly unsafe.
2207 	 */
2208 	ip6n->fb_tnl_dev->features |= NETIF_F_NETNS_LOCAL;
2209 
2210 	err = ip6_fb_tnl_dev_init(ip6n->fb_tnl_dev);
2211 	if (err < 0)
2212 		goto err_register;
2213 
2214 	err = register_netdev(ip6n->fb_tnl_dev);
2215 	if (err < 0)
2216 		goto err_register;
2217 
2218 	t = netdev_priv(ip6n->fb_tnl_dev);
2219 
2220 	strcpy(t->parms.name, ip6n->fb_tnl_dev->name);
2221 	return 0;
2222 
2223 err_register:
2224 	free_netdev(ip6n->fb_tnl_dev);
2225 err_alloc_dev:
2226 	return err;
2227 }
2228 
2229 static void __net_exit ip6_tnl_exit_batch_net(struct list_head *net_list)
2230 {
2231 	struct net *net;
2232 	LIST_HEAD(list);
2233 
2234 	rtnl_lock();
2235 	list_for_each_entry(net, net_list, exit_list)
2236 		ip6_tnl_destroy_tunnels(net, &list);
2237 	unregister_netdevice_many(&list);
2238 	rtnl_unlock();
2239 }
2240 
2241 static struct pernet_operations ip6_tnl_net_ops = {
2242 	.init = ip6_tnl_init_net,
2243 	.exit_batch = ip6_tnl_exit_batch_net,
2244 	.id   = &ip6_tnl_net_id,
2245 	.size = sizeof(struct ip6_tnl_net),
2246 };
2247 
2248 /**
2249  * ip6_tunnel_init - register protocol and reserve needed resources
2250  *
2251  * Return: 0 on success
2252  **/
2253 
2254 static int __init ip6_tunnel_init(void)
2255 {
2256 	int  err;
2257 
2258 	if (!ipv6_mod_enabled())
2259 		return -EOPNOTSUPP;
2260 
2261 	err = register_pernet_device(&ip6_tnl_net_ops);
2262 	if (err < 0)
2263 		goto out_pernet;
2264 
2265 	err = xfrm6_tunnel_register(&ip4ip6_handler, AF_INET);
2266 	if (err < 0) {
2267 		pr_err("%s: can't register ip4ip6\n", __func__);
2268 		goto out_ip4ip6;
2269 	}
2270 
2271 	err = xfrm6_tunnel_register(&ip6ip6_handler, AF_INET6);
2272 	if (err < 0) {
2273 		pr_err("%s: can't register ip6ip6\n", __func__);
2274 		goto out_ip6ip6;
2275 	}
2276 	err = rtnl_link_register(&ip6_link_ops);
2277 	if (err < 0)
2278 		goto rtnl_link_failed;
2279 
2280 	return 0;
2281 
2282 rtnl_link_failed:
2283 	xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6);
2284 out_ip6ip6:
2285 	xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET);
2286 out_ip4ip6:
2287 	unregister_pernet_device(&ip6_tnl_net_ops);
2288 out_pernet:
2289 	return err;
2290 }
2291 
2292 /**
2293  * ip6_tunnel_cleanup - free resources and unregister protocol
2294  **/
2295 
2296 static void __exit ip6_tunnel_cleanup(void)
2297 {
2298 	rtnl_link_unregister(&ip6_link_ops);
2299 	if (xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET))
2300 		pr_info("%s: can't deregister ip4ip6\n", __func__);
2301 
2302 	if (xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6))
2303 		pr_info("%s: can't deregister ip6ip6\n", __func__);
2304 
2305 	unregister_pernet_device(&ip6_tnl_net_ops);
2306 }
2307 
2308 module_init(ip6_tunnel_init);
2309 module_exit(ip6_tunnel_cleanup);
2310