xref: /linux/net/ipv6/ip6_tunnel.c (revision 140eb5227767c6754742020a16d2691222b9c19b)
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_update_pmtu(skb2, rel_info);
646 	}
647 
648 	icmp_send(skb2, rel_type, rel_code, htonl(rel_info));
649 
650 out:
651 	kfree_skb(skb2);
652 	return 0;
653 }
654 
655 static int
656 ip6ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
657 	   u8 type, u8 code, int offset, __be32 info)
658 {
659 	__u32 rel_info = ntohl(info);
660 	int err, rel_msg = 0;
661 	u8 rel_type = type;
662 	u8 rel_code = code;
663 
664 	err = ip6_tnl_err(skb, IPPROTO_IPV6, opt, &rel_type, &rel_code,
665 			  &rel_msg, &rel_info, offset);
666 	if (err < 0)
667 		return err;
668 
669 	if (rel_msg && pskb_may_pull(skb, offset + sizeof(struct ipv6hdr))) {
670 		struct rt6_info *rt;
671 		struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
672 
673 		if (!skb2)
674 			return 0;
675 
676 		skb_dst_drop(skb2);
677 		skb_pull(skb2, offset);
678 		skb_reset_network_header(skb2);
679 
680 		/* Try to guess incoming interface */
681 		rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr,
682 				NULL, 0, 0);
683 
684 		if (rt && rt->dst.dev)
685 			skb2->dev = rt->dst.dev;
686 
687 		icmpv6_send(skb2, rel_type, rel_code, rel_info);
688 
689 		ip6_rt_put(rt);
690 
691 		kfree_skb(skb2);
692 	}
693 
694 	return 0;
695 }
696 
697 static int ip4ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
698 				       const struct ipv6hdr *ipv6h,
699 				       struct sk_buff *skb)
700 {
701 	__u8 dsfield = ipv6_get_dsfield(ipv6h) & ~INET_ECN_MASK;
702 
703 	if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
704 		ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, dsfield);
705 
706 	return IP6_ECN_decapsulate(ipv6h, skb);
707 }
708 
709 static int ip6ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
710 				       const struct ipv6hdr *ipv6h,
711 				       struct sk_buff *skb)
712 {
713 	if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
714 		ipv6_copy_dscp(ipv6_get_dsfield(ipv6h), ipv6_hdr(skb));
715 
716 	return IP6_ECN_decapsulate(ipv6h, skb);
717 }
718 
719 __u32 ip6_tnl_get_cap(struct ip6_tnl *t,
720 			     const struct in6_addr *laddr,
721 			     const struct in6_addr *raddr)
722 {
723 	struct __ip6_tnl_parm *p = &t->parms;
724 	int ltype = ipv6_addr_type(laddr);
725 	int rtype = ipv6_addr_type(raddr);
726 	__u32 flags = 0;
727 
728 	if (ltype == IPV6_ADDR_ANY || rtype == IPV6_ADDR_ANY) {
729 		flags = IP6_TNL_F_CAP_PER_PACKET;
730 	} else if (ltype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
731 		   rtype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
732 		   !((ltype|rtype) & IPV6_ADDR_LOOPBACK) &&
733 		   (!((ltype|rtype) & IPV6_ADDR_LINKLOCAL) || p->link)) {
734 		if (ltype&IPV6_ADDR_UNICAST)
735 			flags |= IP6_TNL_F_CAP_XMIT;
736 		if (rtype&IPV6_ADDR_UNICAST)
737 			flags |= IP6_TNL_F_CAP_RCV;
738 	}
739 	return flags;
740 }
741 EXPORT_SYMBOL(ip6_tnl_get_cap);
742 
743 /* called with rcu_read_lock() */
744 int ip6_tnl_rcv_ctl(struct ip6_tnl *t,
745 				  const struct in6_addr *laddr,
746 				  const struct in6_addr *raddr)
747 {
748 	struct __ip6_tnl_parm *p = &t->parms;
749 	int ret = 0;
750 	struct net *net = t->net;
751 
752 	if ((p->flags & IP6_TNL_F_CAP_RCV) ||
753 	    ((p->flags & IP6_TNL_F_CAP_PER_PACKET) &&
754 	     (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_RCV))) {
755 		struct net_device *ldev = NULL;
756 
757 		if (p->link)
758 			ldev = dev_get_by_index_rcu(net, p->link);
759 
760 		if ((ipv6_addr_is_multicast(laddr) ||
761 		     likely(ipv6_chk_addr(net, laddr, ldev, 0))) &&
762 		    ((p->flags & IP6_TNL_F_ALLOW_LOCAL_REMOTE) ||
763 		     likely(!ipv6_chk_addr(net, raddr, NULL, 0))))
764 			ret = 1;
765 	}
766 	return ret;
767 }
768 EXPORT_SYMBOL_GPL(ip6_tnl_rcv_ctl);
769 
770 static int __ip6_tnl_rcv(struct ip6_tnl *tunnel, struct sk_buff *skb,
771 			 const struct tnl_ptk_info *tpi,
772 			 struct metadata_dst *tun_dst,
773 			 int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
774 						const struct ipv6hdr *ipv6h,
775 						struct sk_buff *skb),
776 			 bool log_ecn_err)
777 {
778 	struct pcpu_sw_netstats *tstats;
779 	const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
780 	int err;
781 
782 	if ((!(tpi->flags & TUNNEL_CSUM) &&
783 	     (tunnel->parms.i_flags & TUNNEL_CSUM)) ||
784 	    ((tpi->flags & TUNNEL_CSUM) &&
785 	     !(tunnel->parms.i_flags & TUNNEL_CSUM))) {
786 		tunnel->dev->stats.rx_crc_errors++;
787 		tunnel->dev->stats.rx_errors++;
788 		goto drop;
789 	}
790 
791 	if (tunnel->parms.i_flags & TUNNEL_SEQ) {
792 		if (!(tpi->flags & TUNNEL_SEQ) ||
793 		    (tunnel->i_seqno &&
794 		     (s32)(ntohl(tpi->seq) - tunnel->i_seqno) < 0)) {
795 			tunnel->dev->stats.rx_fifo_errors++;
796 			tunnel->dev->stats.rx_errors++;
797 			goto drop;
798 		}
799 		tunnel->i_seqno = ntohl(tpi->seq) + 1;
800 	}
801 
802 	skb->protocol = tpi->proto;
803 
804 	/* Warning: All skb pointers will be invalidated! */
805 	if (tunnel->dev->type == ARPHRD_ETHER) {
806 		if (!pskb_may_pull(skb, ETH_HLEN)) {
807 			tunnel->dev->stats.rx_length_errors++;
808 			tunnel->dev->stats.rx_errors++;
809 			goto drop;
810 		}
811 
812 		ipv6h = ipv6_hdr(skb);
813 		skb->protocol = eth_type_trans(skb, tunnel->dev);
814 		skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
815 	} else {
816 		skb->dev = tunnel->dev;
817 	}
818 
819 	skb_reset_network_header(skb);
820 	memset(skb->cb, 0, sizeof(struct inet6_skb_parm));
821 
822 	__skb_tunnel_rx(skb, tunnel->dev, tunnel->net);
823 
824 	err = dscp_ecn_decapsulate(tunnel, ipv6h, skb);
825 	if (unlikely(err)) {
826 		if (log_ecn_err)
827 			net_info_ratelimited("non-ECT from %pI6 with DS=%#x\n",
828 					     &ipv6h->saddr,
829 					     ipv6_get_dsfield(ipv6h));
830 		if (err > 1) {
831 			++tunnel->dev->stats.rx_frame_errors;
832 			++tunnel->dev->stats.rx_errors;
833 			goto drop;
834 		}
835 	}
836 
837 	tstats = this_cpu_ptr(tunnel->dev->tstats);
838 	u64_stats_update_begin(&tstats->syncp);
839 	tstats->rx_packets++;
840 	tstats->rx_bytes += skb->len;
841 	u64_stats_update_end(&tstats->syncp);
842 
843 	skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(tunnel->dev)));
844 
845 	if (tun_dst)
846 		skb_dst_set(skb, (struct dst_entry *)tun_dst);
847 
848 	gro_cells_receive(&tunnel->gro_cells, skb);
849 	return 0;
850 
851 drop:
852 	if (tun_dst)
853 		dst_release((struct dst_entry *)tun_dst);
854 	kfree_skb(skb);
855 	return 0;
856 }
857 
858 int ip6_tnl_rcv(struct ip6_tnl *t, struct sk_buff *skb,
859 		const struct tnl_ptk_info *tpi,
860 		struct metadata_dst *tun_dst,
861 		bool log_ecn_err)
862 {
863 	return __ip6_tnl_rcv(t, skb, tpi, NULL, ip6ip6_dscp_ecn_decapsulate,
864 			     log_ecn_err);
865 }
866 EXPORT_SYMBOL(ip6_tnl_rcv);
867 
868 static const struct tnl_ptk_info tpi_v6 = {
869 	/* no tunnel info required for ipxip6. */
870 	.proto = htons(ETH_P_IPV6),
871 };
872 
873 static const struct tnl_ptk_info tpi_v4 = {
874 	/* no tunnel info required for ipxip6. */
875 	.proto = htons(ETH_P_IP),
876 };
877 
878 static int ipxip6_rcv(struct sk_buff *skb, u8 ipproto,
879 		      const struct tnl_ptk_info *tpi,
880 		      int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
881 						  const struct ipv6hdr *ipv6h,
882 						  struct sk_buff *skb))
883 {
884 	struct ip6_tnl *t;
885 	const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
886 	struct metadata_dst *tun_dst = NULL;
887 	int ret = -1;
888 
889 	rcu_read_lock();
890 	t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->saddr, &ipv6h->daddr);
891 
892 	if (t) {
893 		u8 tproto = READ_ONCE(t->parms.proto);
894 
895 		if (tproto != ipproto && tproto != 0)
896 			goto drop;
897 		if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
898 			goto drop;
899 		if (!ip6_tnl_rcv_ctl(t, &ipv6h->daddr, &ipv6h->saddr))
900 			goto drop;
901 		if (iptunnel_pull_header(skb, 0, tpi->proto, false))
902 			goto drop;
903 		if (t->parms.collect_md) {
904 			tun_dst = ipv6_tun_rx_dst(skb, 0, 0, 0);
905 			if (!tun_dst)
906 				goto drop;
907 		}
908 		ret = __ip6_tnl_rcv(t, skb, tpi, tun_dst, dscp_ecn_decapsulate,
909 				    log_ecn_error);
910 	}
911 
912 	rcu_read_unlock();
913 
914 	return ret;
915 
916 drop:
917 	rcu_read_unlock();
918 	kfree_skb(skb);
919 	return 0;
920 }
921 
922 static int ip4ip6_rcv(struct sk_buff *skb)
923 {
924 	return ipxip6_rcv(skb, IPPROTO_IPIP, &tpi_v4,
925 			  ip4ip6_dscp_ecn_decapsulate);
926 }
927 
928 static int ip6ip6_rcv(struct sk_buff *skb)
929 {
930 	return ipxip6_rcv(skb, IPPROTO_IPV6, &tpi_v6,
931 			  ip6ip6_dscp_ecn_decapsulate);
932 }
933 
934 struct ipv6_tel_txoption {
935 	struct ipv6_txoptions ops;
936 	__u8 dst_opt[8];
937 };
938 
939 static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit)
940 {
941 	memset(opt, 0, sizeof(struct ipv6_tel_txoption));
942 
943 	opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT;
944 	opt->dst_opt[3] = 1;
945 	opt->dst_opt[4] = encap_limit;
946 	opt->dst_opt[5] = IPV6_TLV_PADN;
947 	opt->dst_opt[6] = 1;
948 
949 	opt->ops.dst1opt = (struct ipv6_opt_hdr *) opt->dst_opt;
950 	opt->ops.opt_nflen = 8;
951 }
952 
953 /**
954  * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
955  *   @t: the outgoing tunnel device
956  *   @hdr: IPv6 header from the incoming packet
957  *
958  * Description:
959  *   Avoid trivial tunneling loop by checking that tunnel exit-point
960  *   doesn't match source of incoming packet.
961  *
962  * Return:
963  *   1 if conflict,
964  *   0 else
965  **/
966 
967 static inline bool
968 ip6_tnl_addr_conflict(const struct ip6_tnl *t, const struct ipv6hdr *hdr)
969 {
970 	return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
971 }
972 
973 int ip6_tnl_xmit_ctl(struct ip6_tnl *t,
974 		     const struct in6_addr *laddr,
975 		     const struct in6_addr *raddr)
976 {
977 	struct __ip6_tnl_parm *p = &t->parms;
978 	int ret = 0;
979 	struct net *net = t->net;
980 
981 	if ((p->flags & IP6_TNL_F_CAP_XMIT) ||
982 	    ((p->flags & IP6_TNL_F_CAP_PER_PACKET) &&
983 	     (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_XMIT))) {
984 		struct net_device *ldev = NULL;
985 
986 		rcu_read_lock();
987 		if (p->link)
988 			ldev = dev_get_by_index_rcu(net, p->link);
989 
990 		if (unlikely(!ipv6_chk_addr(net, laddr, ldev, 0)))
991 			pr_warn("%s xmit: Local address not yet configured!\n",
992 				p->name);
993 		else if (!(p->flags & IP6_TNL_F_ALLOW_LOCAL_REMOTE) &&
994 			 !ipv6_addr_is_multicast(raddr) &&
995 			 unlikely(ipv6_chk_addr(net, raddr, NULL, 0)))
996 			pr_warn("%s xmit: Routing loop! Remote address found on this node!\n",
997 				p->name);
998 		else
999 			ret = 1;
1000 		rcu_read_unlock();
1001 	}
1002 	return ret;
1003 }
1004 EXPORT_SYMBOL_GPL(ip6_tnl_xmit_ctl);
1005 
1006 /**
1007  * ip6_tnl_xmit - encapsulate packet and send
1008  *   @skb: the outgoing socket buffer
1009  *   @dev: the outgoing tunnel device
1010  *   @dsfield: dscp code for outer header
1011  *   @fl6: flow of tunneled packet
1012  *   @encap_limit: encapsulation limit
1013  *   @pmtu: Path MTU is stored if packet is too big
1014  *   @proto: next header value
1015  *
1016  * Description:
1017  *   Build new header and do some sanity checks on the packet before sending
1018  *   it.
1019  *
1020  * Return:
1021  *   0 on success
1022  *   -1 fail
1023  *   %-EMSGSIZE message too big. return mtu in this case.
1024  **/
1025 
1026 int ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev, __u8 dsfield,
1027 		 struct flowi6 *fl6, int encap_limit, __u32 *pmtu,
1028 		 __u8 proto)
1029 {
1030 	struct ip6_tnl *t = netdev_priv(dev);
1031 	struct net *net = t->net;
1032 	struct net_device_stats *stats = &t->dev->stats;
1033 	struct ipv6hdr *ipv6h;
1034 	struct ipv6_tel_txoption opt;
1035 	struct dst_entry *dst = NULL, *ndst = NULL;
1036 	struct net_device *tdev;
1037 	int mtu;
1038 	unsigned int eth_hlen = t->dev->type == ARPHRD_ETHER ? ETH_HLEN : 0;
1039 	unsigned int psh_hlen = sizeof(struct ipv6hdr) + t->encap_hlen;
1040 	unsigned int max_headroom = psh_hlen;
1041 	bool use_cache = false;
1042 	u8 hop_limit;
1043 	int err = -1;
1044 
1045 	if (t->parms.collect_md) {
1046 		hop_limit = skb_tunnel_info(skb)->key.ttl;
1047 		goto route_lookup;
1048 	} else {
1049 		hop_limit = t->parms.hop_limit;
1050 	}
1051 
1052 	/* NBMA tunnel */
1053 	if (ipv6_addr_any(&t->parms.raddr)) {
1054 		if (skb->protocol == htons(ETH_P_IPV6)) {
1055 			struct in6_addr *addr6;
1056 			struct neighbour *neigh;
1057 			int addr_type;
1058 
1059 			if (!skb_dst(skb))
1060 				goto tx_err_link_failure;
1061 
1062 			neigh = dst_neigh_lookup(skb_dst(skb),
1063 						 &ipv6_hdr(skb)->daddr);
1064 			if (!neigh)
1065 				goto tx_err_link_failure;
1066 
1067 			addr6 = (struct in6_addr *)&neigh->primary_key;
1068 			addr_type = ipv6_addr_type(addr6);
1069 
1070 			if (addr_type == IPV6_ADDR_ANY)
1071 				addr6 = &ipv6_hdr(skb)->daddr;
1072 
1073 			memcpy(&fl6->daddr, addr6, sizeof(fl6->daddr));
1074 			neigh_release(neigh);
1075 		}
1076 	} else if (t->parms.proto != 0 && !(t->parms.flags &
1077 					    (IP6_TNL_F_USE_ORIG_TCLASS |
1078 					     IP6_TNL_F_USE_ORIG_FWMARK))) {
1079 		/* enable the cache only if neither the outer protocol nor the
1080 		 * routing decision depends 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 (skb->protocol == htons(ETH_P_IPV6)) {
1127 		if (mtu < IPV6_MIN_MTU)
1128 			mtu = IPV6_MIN_MTU;
1129 	} else if (mtu < 576) {
1130 		mtu = 576;
1131 	}
1132 
1133 	skb_dst_update_pmtu(skb, mtu);
1134 	if (skb->len - t->tun_hlen - eth_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 	hop_limit = hop_limit ? : ip6_dst_hoplimit(dst);
1186 
1187 	/* Calculate max headroom for all the headers and adjust
1188 	 * needed_headroom if necessary.
1189 	 */
1190 	max_headroom = LL_RESERVED_SPACE(dst->dev) + sizeof(struct ipv6hdr)
1191 			+ dst->header_len + t->hlen;
1192 	if (max_headroom > dev->needed_headroom)
1193 		dev->needed_headroom = max_headroom;
1194 
1195 	err = ip6_tnl_encap(skb, t, &proto, fl6);
1196 	if (err)
1197 		return err;
1198 
1199 	skb_push(skb, sizeof(struct ipv6hdr));
1200 	skb_reset_network_header(skb);
1201 	ipv6h = ipv6_hdr(skb);
1202 	ip6_flow_hdr(ipv6h, dsfield,
1203 		     ip6_make_flowlabel(net, skb, fl6->flowlabel, true, fl6));
1204 	ipv6h->hop_limit = hop_limit;
1205 	ipv6h->nexthdr = proto;
1206 	ipv6h->saddr = fl6->saddr;
1207 	ipv6h->daddr = fl6->daddr;
1208 	ip6tunnel_xmit(NULL, skb, dev);
1209 	return 0;
1210 tx_err_link_failure:
1211 	stats->tx_carrier_errors++;
1212 	dst_link_failure(skb);
1213 tx_err_dst_release:
1214 	dst_release(dst);
1215 	return err;
1216 }
1217 EXPORT_SYMBOL(ip6_tnl_xmit);
1218 
1219 static inline int
1220 ip4ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1221 {
1222 	struct ip6_tnl *t = netdev_priv(dev);
1223 	const struct iphdr  *iph = ip_hdr(skb);
1224 	int encap_limit = -1;
1225 	struct flowi6 fl6;
1226 	__u8 dsfield;
1227 	__u32 mtu;
1228 	u8 tproto;
1229 	int err;
1230 
1231 	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1232 
1233 	tproto = READ_ONCE(t->parms.proto);
1234 	if (tproto != IPPROTO_IPIP && tproto != 0)
1235 		return -1;
1236 
1237 	if (t->parms.collect_md) {
1238 		struct ip_tunnel_info *tun_info;
1239 		const struct ip_tunnel_key *key;
1240 
1241 		tun_info = skb_tunnel_info(skb);
1242 		if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
1243 			     ip_tunnel_info_af(tun_info) != AF_INET6))
1244 			return -1;
1245 		key = &tun_info->key;
1246 		memset(&fl6, 0, sizeof(fl6));
1247 		fl6.flowi6_proto = IPPROTO_IPIP;
1248 		fl6.daddr = key->u.ipv6.dst;
1249 		fl6.flowlabel = key->label;
1250 		dsfield =  key->tos;
1251 	} else {
1252 		if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1253 			encap_limit = t->parms.encap_limit;
1254 
1255 		memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
1256 		fl6.flowi6_proto = IPPROTO_IPIP;
1257 
1258 		if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1259 			dsfield = ipv4_get_dsfield(iph);
1260 		else
1261 			dsfield = ip6_tclass(t->parms.flowinfo);
1262 		if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
1263 			fl6.flowi6_mark = skb->mark;
1264 		else
1265 			fl6.flowi6_mark = t->parms.fwmark;
1266 	}
1267 
1268 	fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
1269 
1270 	if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP6))
1271 		return -1;
1272 
1273 	dsfield = INET_ECN_encapsulate(dsfield, ipv4_get_dsfield(iph));
1274 
1275 	skb_set_inner_ipproto(skb, IPPROTO_IPIP);
1276 
1277 	err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
1278 			   IPPROTO_IPIP);
1279 	if (err != 0) {
1280 		/* XXX: send ICMP error even if DF is not set. */
1281 		if (err == -EMSGSIZE)
1282 			icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
1283 				  htonl(mtu));
1284 		return -1;
1285 	}
1286 
1287 	return 0;
1288 }
1289 
1290 static inline int
1291 ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1292 {
1293 	struct ip6_tnl *t = netdev_priv(dev);
1294 	struct ipv6hdr *ipv6h = ipv6_hdr(skb);
1295 	int encap_limit = -1;
1296 	__u16 offset;
1297 	struct flowi6 fl6;
1298 	__u8 dsfield;
1299 	__u32 mtu;
1300 	u8 tproto;
1301 	int err;
1302 
1303 	tproto = READ_ONCE(t->parms.proto);
1304 	if ((tproto != IPPROTO_IPV6 && tproto != 0) ||
1305 	    ip6_tnl_addr_conflict(t, ipv6h))
1306 		return -1;
1307 
1308 	if (t->parms.collect_md) {
1309 		struct ip_tunnel_info *tun_info;
1310 		const struct ip_tunnel_key *key;
1311 
1312 		tun_info = skb_tunnel_info(skb);
1313 		if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
1314 			     ip_tunnel_info_af(tun_info) != AF_INET6))
1315 			return -1;
1316 		key = &tun_info->key;
1317 		memset(&fl6, 0, sizeof(fl6));
1318 		fl6.flowi6_proto = IPPROTO_IPV6;
1319 		fl6.daddr = key->u.ipv6.dst;
1320 		fl6.flowlabel = key->label;
1321 		dsfield = key->tos;
1322 	} else {
1323 		offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
1324 		/* ip6_tnl_parse_tlv_enc_lim() might have reallocated skb->head */
1325 		ipv6h = ipv6_hdr(skb);
1326 		if (offset > 0) {
1327 			struct ipv6_tlv_tnl_enc_lim *tel;
1328 
1329 			tel = (void *)&skb_network_header(skb)[offset];
1330 			if (tel->encap_limit == 0) {
1331 				icmpv6_send(skb, ICMPV6_PARAMPROB,
1332 					    ICMPV6_HDR_FIELD, offset + 2);
1333 				return -1;
1334 			}
1335 			encap_limit = tel->encap_limit - 1;
1336 		} else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) {
1337 			encap_limit = t->parms.encap_limit;
1338 		}
1339 
1340 		memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
1341 		fl6.flowi6_proto = IPPROTO_IPV6;
1342 
1343 		if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1344 			dsfield = ipv6_get_dsfield(ipv6h);
1345 		else
1346 			dsfield = ip6_tclass(t->parms.flowinfo);
1347 		if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
1348 			fl6.flowlabel |= ip6_flowlabel(ipv6h);
1349 		if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
1350 			fl6.flowi6_mark = skb->mark;
1351 		else
1352 			fl6.flowi6_mark = t->parms.fwmark;
1353 	}
1354 
1355 	fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
1356 
1357 	if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP6))
1358 		return -1;
1359 
1360 	dsfield = INET_ECN_encapsulate(dsfield, ipv6_get_dsfield(ipv6h));
1361 
1362 	skb_set_inner_ipproto(skb, IPPROTO_IPV6);
1363 
1364 	err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
1365 			   IPPROTO_IPV6);
1366 	if (err != 0) {
1367 		if (err == -EMSGSIZE)
1368 			icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
1369 		return -1;
1370 	}
1371 
1372 	return 0;
1373 }
1374 
1375 static netdev_tx_t
1376 ip6_tnl_start_xmit(struct sk_buff *skb, struct net_device *dev)
1377 {
1378 	struct ip6_tnl *t = netdev_priv(dev);
1379 	struct net_device_stats *stats = &t->dev->stats;
1380 	int ret;
1381 
1382 	switch (skb->protocol) {
1383 	case htons(ETH_P_IP):
1384 		ret = ip4ip6_tnl_xmit(skb, dev);
1385 		break;
1386 	case htons(ETH_P_IPV6):
1387 		ret = ip6ip6_tnl_xmit(skb, dev);
1388 		break;
1389 	default:
1390 		goto tx_err;
1391 	}
1392 
1393 	if (ret < 0)
1394 		goto tx_err;
1395 
1396 	return NETDEV_TX_OK;
1397 
1398 tx_err:
1399 	stats->tx_errors++;
1400 	stats->tx_dropped++;
1401 	kfree_skb(skb);
1402 	return NETDEV_TX_OK;
1403 }
1404 
1405 static void ip6_tnl_link_config(struct ip6_tnl *t)
1406 {
1407 	struct net_device *dev = t->dev;
1408 	struct __ip6_tnl_parm *p = &t->parms;
1409 	struct flowi6 *fl6 = &t->fl.u.ip6;
1410 	int t_hlen;
1411 
1412 	memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
1413 	memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
1414 
1415 	/* Set up flowi template */
1416 	fl6->saddr = p->laddr;
1417 	fl6->daddr = p->raddr;
1418 	fl6->flowi6_oif = p->link;
1419 	fl6->flowlabel = 0;
1420 
1421 	if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
1422 		fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
1423 	if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
1424 		fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
1425 
1426 	p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
1427 	p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
1428 
1429 	if (p->flags&IP6_TNL_F_CAP_XMIT && p->flags&IP6_TNL_F_CAP_RCV)
1430 		dev->flags |= IFF_POINTOPOINT;
1431 	else
1432 		dev->flags &= ~IFF_POINTOPOINT;
1433 
1434 	t->tun_hlen = 0;
1435 	t->hlen = t->encap_hlen + t->tun_hlen;
1436 	t_hlen = t->hlen + sizeof(struct ipv6hdr);
1437 
1438 	if (p->flags & IP6_TNL_F_CAP_XMIT) {
1439 		int strict = (ipv6_addr_type(&p->raddr) &
1440 			      (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
1441 
1442 		struct rt6_info *rt = rt6_lookup(t->net,
1443 						 &p->raddr, &p->laddr,
1444 						 p->link, strict);
1445 
1446 		if (!rt)
1447 			return;
1448 
1449 		if (rt->dst.dev) {
1450 			dev->hard_header_len = rt->dst.dev->hard_header_len +
1451 				t_hlen;
1452 
1453 			dev->mtu = rt->dst.dev->mtu - t_hlen;
1454 			if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1455 				dev->mtu -= 8;
1456 
1457 			if (dev->mtu < IPV6_MIN_MTU)
1458 				dev->mtu = IPV6_MIN_MTU;
1459 		}
1460 		ip6_rt_put(rt);
1461 	}
1462 }
1463 
1464 /**
1465  * ip6_tnl_change - update the tunnel parameters
1466  *   @t: tunnel to be changed
1467  *   @p: tunnel configuration parameters
1468  *
1469  * Description:
1470  *   ip6_tnl_change() updates the tunnel parameters
1471  **/
1472 
1473 static int
1474 ip6_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p)
1475 {
1476 	t->parms.laddr = p->laddr;
1477 	t->parms.raddr = p->raddr;
1478 	t->parms.flags = p->flags;
1479 	t->parms.hop_limit = p->hop_limit;
1480 	t->parms.encap_limit = p->encap_limit;
1481 	t->parms.flowinfo = p->flowinfo;
1482 	t->parms.link = p->link;
1483 	t->parms.proto = p->proto;
1484 	t->parms.fwmark = p->fwmark;
1485 	dst_cache_reset(&t->dst_cache);
1486 	ip6_tnl_link_config(t);
1487 	return 0;
1488 }
1489 
1490 static int ip6_tnl_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
1491 {
1492 	struct net *net = t->net;
1493 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1494 	int err;
1495 
1496 	ip6_tnl_unlink(ip6n, t);
1497 	synchronize_net();
1498 	err = ip6_tnl_change(t, p);
1499 	ip6_tnl_link(ip6n, t);
1500 	netdev_state_change(t->dev);
1501 	return err;
1502 }
1503 
1504 static int ip6_tnl0_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
1505 {
1506 	/* for default tnl0 device allow to change only the proto */
1507 	t->parms.proto = p->proto;
1508 	netdev_state_change(t->dev);
1509 	return 0;
1510 }
1511 
1512 static void
1513 ip6_tnl_parm_from_user(struct __ip6_tnl_parm *p, const struct ip6_tnl_parm *u)
1514 {
1515 	p->laddr = u->laddr;
1516 	p->raddr = u->raddr;
1517 	p->flags = u->flags;
1518 	p->hop_limit = u->hop_limit;
1519 	p->encap_limit = u->encap_limit;
1520 	p->flowinfo = u->flowinfo;
1521 	p->link = u->link;
1522 	p->proto = u->proto;
1523 	memcpy(p->name, u->name, sizeof(u->name));
1524 }
1525 
1526 static void
1527 ip6_tnl_parm_to_user(struct ip6_tnl_parm *u, const struct __ip6_tnl_parm *p)
1528 {
1529 	u->laddr = p->laddr;
1530 	u->raddr = p->raddr;
1531 	u->flags = p->flags;
1532 	u->hop_limit = p->hop_limit;
1533 	u->encap_limit = p->encap_limit;
1534 	u->flowinfo = p->flowinfo;
1535 	u->link = p->link;
1536 	u->proto = p->proto;
1537 	memcpy(u->name, p->name, sizeof(u->name));
1538 }
1539 
1540 /**
1541  * ip6_tnl_ioctl - configure ipv6 tunnels from userspace
1542  *   @dev: virtual device associated with tunnel
1543  *   @ifr: parameters passed from userspace
1544  *   @cmd: command to be performed
1545  *
1546  * Description:
1547  *   ip6_tnl_ioctl() is used for managing IPv6 tunnels
1548  *   from userspace.
1549  *
1550  *   The possible commands are the following:
1551  *     %SIOCGETTUNNEL: get tunnel parameters for device
1552  *     %SIOCADDTUNNEL: add tunnel matching given tunnel parameters
1553  *     %SIOCCHGTUNNEL: change tunnel parameters to those given
1554  *     %SIOCDELTUNNEL: delete tunnel
1555  *
1556  *   The fallback device "ip6tnl0", created during module
1557  *   initialization, can be used for creating other tunnel devices.
1558  *
1559  * Return:
1560  *   0 on success,
1561  *   %-EFAULT if unable to copy data to or from userspace,
1562  *   %-EPERM if current process hasn't %CAP_NET_ADMIN set
1563  *   %-EINVAL if passed tunnel parameters are invalid,
1564  *   %-EEXIST if changing a tunnel's parameters would cause a conflict
1565  *   %-ENODEV if attempting to change or delete a nonexisting device
1566  **/
1567 
1568 static int
1569 ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1570 {
1571 	int err = 0;
1572 	struct ip6_tnl_parm p;
1573 	struct __ip6_tnl_parm p1;
1574 	struct ip6_tnl *t = netdev_priv(dev);
1575 	struct net *net = t->net;
1576 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1577 
1578 	memset(&p1, 0, sizeof(p1));
1579 
1580 	switch (cmd) {
1581 	case SIOCGETTUNNEL:
1582 		if (dev == ip6n->fb_tnl_dev) {
1583 			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1584 				err = -EFAULT;
1585 				break;
1586 			}
1587 			ip6_tnl_parm_from_user(&p1, &p);
1588 			t = ip6_tnl_locate(net, &p1, 0);
1589 			if (IS_ERR(t))
1590 				t = netdev_priv(dev);
1591 		} else {
1592 			memset(&p, 0, sizeof(p));
1593 		}
1594 		ip6_tnl_parm_to_user(&p, &t->parms);
1595 		if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) {
1596 			err = -EFAULT;
1597 		}
1598 		break;
1599 	case SIOCADDTUNNEL:
1600 	case SIOCCHGTUNNEL:
1601 		err = -EPERM;
1602 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1603 			break;
1604 		err = -EFAULT;
1605 		if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1606 			break;
1607 		err = -EINVAL;
1608 		if (p.proto != IPPROTO_IPV6 && p.proto != IPPROTO_IPIP &&
1609 		    p.proto != 0)
1610 			break;
1611 		ip6_tnl_parm_from_user(&p1, &p);
1612 		t = ip6_tnl_locate(net, &p1, cmd == SIOCADDTUNNEL);
1613 		if (cmd == SIOCCHGTUNNEL) {
1614 			if (!IS_ERR(t)) {
1615 				if (t->dev != dev) {
1616 					err = -EEXIST;
1617 					break;
1618 				}
1619 			} else
1620 				t = netdev_priv(dev);
1621 			if (dev == ip6n->fb_tnl_dev)
1622 				err = ip6_tnl0_update(t, &p1);
1623 			else
1624 				err = ip6_tnl_update(t, &p1);
1625 		}
1626 		if (!IS_ERR(t)) {
1627 			err = 0;
1628 			ip6_tnl_parm_to_user(&p, &t->parms);
1629 			if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1630 				err = -EFAULT;
1631 
1632 		} else {
1633 			err = PTR_ERR(t);
1634 		}
1635 		break;
1636 	case SIOCDELTUNNEL:
1637 		err = -EPERM;
1638 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1639 			break;
1640 
1641 		if (dev == ip6n->fb_tnl_dev) {
1642 			err = -EFAULT;
1643 			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1644 				break;
1645 			err = -ENOENT;
1646 			ip6_tnl_parm_from_user(&p1, &p);
1647 			t = ip6_tnl_locate(net, &p1, 0);
1648 			if (IS_ERR(t))
1649 				break;
1650 			err = -EPERM;
1651 			if (t->dev == ip6n->fb_tnl_dev)
1652 				break;
1653 			dev = t->dev;
1654 		}
1655 		err = 0;
1656 		unregister_netdevice(dev);
1657 		break;
1658 	default:
1659 		err = -EINVAL;
1660 	}
1661 	return err;
1662 }
1663 
1664 /**
1665  * ip6_tnl_change_mtu - change mtu manually for tunnel device
1666  *   @dev: virtual device associated with tunnel
1667  *   @new_mtu: the new mtu
1668  *
1669  * Return:
1670  *   0 on success,
1671  *   %-EINVAL if mtu too small
1672  **/
1673 
1674 int ip6_tnl_change_mtu(struct net_device *dev, int new_mtu)
1675 {
1676 	struct ip6_tnl *tnl = netdev_priv(dev);
1677 
1678 	if (tnl->parms.proto == IPPROTO_IPV6) {
1679 		if (new_mtu < IPV6_MIN_MTU)
1680 			return -EINVAL;
1681 	} else {
1682 		if (new_mtu < ETH_MIN_MTU)
1683 			return -EINVAL;
1684 	}
1685 	if (new_mtu > 0xFFF8 - dev->hard_header_len)
1686 		return -EINVAL;
1687 	dev->mtu = new_mtu;
1688 	return 0;
1689 }
1690 EXPORT_SYMBOL(ip6_tnl_change_mtu);
1691 
1692 int ip6_tnl_get_iflink(const struct net_device *dev)
1693 {
1694 	struct ip6_tnl *t = netdev_priv(dev);
1695 
1696 	return t->parms.link;
1697 }
1698 EXPORT_SYMBOL(ip6_tnl_get_iflink);
1699 
1700 int ip6_tnl_encap_add_ops(const struct ip6_tnl_encap_ops *ops,
1701 			  unsigned int num)
1702 {
1703 	if (num >= MAX_IPTUN_ENCAP_OPS)
1704 		return -ERANGE;
1705 
1706 	return !cmpxchg((const struct ip6_tnl_encap_ops **)
1707 			&ip6tun_encaps[num],
1708 			NULL, ops) ? 0 : -1;
1709 }
1710 EXPORT_SYMBOL(ip6_tnl_encap_add_ops);
1711 
1712 int ip6_tnl_encap_del_ops(const struct ip6_tnl_encap_ops *ops,
1713 			  unsigned int num)
1714 {
1715 	int ret;
1716 
1717 	if (num >= MAX_IPTUN_ENCAP_OPS)
1718 		return -ERANGE;
1719 
1720 	ret = (cmpxchg((const struct ip6_tnl_encap_ops **)
1721 		       &ip6tun_encaps[num],
1722 		       ops, NULL) == ops) ? 0 : -1;
1723 
1724 	synchronize_net();
1725 
1726 	return ret;
1727 }
1728 EXPORT_SYMBOL(ip6_tnl_encap_del_ops);
1729 
1730 int ip6_tnl_encap_setup(struct ip6_tnl *t,
1731 			struct ip_tunnel_encap *ipencap)
1732 {
1733 	int hlen;
1734 
1735 	memset(&t->encap, 0, sizeof(t->encap));
1736 
1737 	hlen = ip6_encap_hlen(ipencap);
1738 	if (hlen < 0)
1739 		return hlen;
1740 
1741 	t->encap.type = ipencap->type;
1742 	t->encap.sport = ipencap->sport;
1743 	t->encap.dport = ipencap->dport;
1744 	t->encap.flags = ipencap->flags;
1745 
1746 	t->encap_hlen = hlen;
1747 	t->hlen = t->encap_hlen + t->tun_hlen;
1748 
1749 	return 0;
1750 }
1751 EXPORT_SYMBOL_GPL(ip6_tnl_encap_setup);
1752 
1753 static const struct net_device_ops ip6_tnl_netdev_ops = {
1754 	.ndo_init	= ip6_tnl_dev_init,
1755 	.ndo_uninit	= ip6_tnl_dev_uninit,
1756 	.ndo_start_xmit = ip6_tnl_start_xmit,
1757 	.ndo_do_ioctl	= ip6_tnl_ioctl,
1758 	.ndo_change_mtu = ip6_tnl_change_mtu,
1759 	.ndo_get_stats	= ip6_get_stats,
1760 	.ndo_get_iflink = ip6_tnl_get_iflink,
1761 };
1762 
1763 #define IPXIPX_FEATURES (NETIF_F_SG |		\
1764 			 NETIF_F_FRAGLIST |	\
1765 			 NETIF_F_HIGHDMA |	\
1766 			 NETIF_F_GSO_SOFTWARE |	\
1767 			 NETIF_F_HW_CSUM)
1768 
1769 /**
1770  * ip6_tnl_dev_setup - setup virtual tunnel device
1771  *   @dev: virtual device associated with tunnel
1772  *
1773  * Description:
1774  *   Initialize function pointers and device parameters
1775  **/
1776 
1777 static void ip6_tnl_dev_setup(struct net_device *dev)
1778 {
1779 	dev->netdev_ops = &ip6_tnl_netdev_ops;
1780 	dev->needs_free_netdev = true;
1781 	dev->priv_destructor = ip6_dev_free;
1782 
1783 	dev->type = ARPHRD_TUNNEL6;
1784 	dev->flags |= IFF_NOARP;
1785 	dev->addr_len = sizeof(struct in6_addr);
1786 	dev->features |= NETIF_F_LLTX;
1787 	netif_keep_dst(dev);
1788 
1789 	dev->features		|= IPXIPX_FEATURES;
1790 	dev->hw_features	|= IPXIPX_FEATURES;
1791 
1792 	/* This perm addr will be used as interface identifier by IPv6 */
1793 	dev->addr_assign_type = NET_ADDR_RANDOM;
1794 	eth_random_addr(dev->perm_addr);
1795 }
1796 
1797 
1798 /**
1799  * ip6_tnl_dev_init_gen - general initializer for all tunnel devices
1800  *   @dev: virtual device associated with tunnel
1801  **/
1802 
1803 static inline int
1804 ip6_tnl_dev_init_gen(struct net_device *dev)
1805 {
1806 	struct ip6_tnl *t = netdev_priv(dev);
1807 	int ret;
1808 	int t_hlen;
1809 
1810 	t->dev = dev;
1811 	t->net = dev_net(dev);
1812 	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1813 	if (!dev->tstats)
1814 		return -ENOMEM;
1815 
1816 	ret = dst_cache_init(&t->dst_cache, GFP_KERNEL);
1817 	if (ret)
1818 		goto free_stats;
1819 
1820 	ret = gro_cells_init(&t->gro_cells, dev);
1821 	if (ret)
1822 		goto destroy_dst;
1823 
1824 	t->tun_hlen = 0;
1825 	t->hlen = t->encap_hlen + t->tun_hlen;
1826 	t_hlen = t->hlen + sizeof(struct ipv6hdr);
1827 
1828 	dev->type = ARPHRD_TUNNEL6;
1829 	dev->hard_header_len = LL_MAX_HEADER + t_hlen;
1830 	dev->mtu = ETH_DATA_LEN - t_hlen;
1831 	if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1832 		dev->mtu -= 8;
1833 	dev->min_mtu = ETH_MIN_MTU;
1834 	dev->max_mtu = 0xFFF8 - dev->hard_header_len;
1835 
1836 	return 0;
1837 
1838 destroy_dst:
1839 	dst_cache_destroy(&t->dst_cache);
1840 free_stats:
1841 	free_percpu(dev->tstats);
1842 	dev->tstats = NULL;
1843 
1844 	return ret;
1845 }
1846 
1847 /**
1848  * ip6_tnl_dev_init - initializer for all non fallback tunnel devices
1849  *   @dev: virtual device associated with tunnel
1850  **/
1851 
1852 static int ip6_tnl_dev_init(struct net_device *dev)
1853 {
1854 	struct ip6_tnl *t = netdev_priv(dev);
1855 	int err = ip6_tnl_dev_init_gen(dev);
1856 
1857 	if (err)
1858 		return err;
1859 	ip6_tnl_link_config(t);
1860 	if (t->parms.collect_md) {
1861 		dev->features |= NETIF_F_NETNS_LOCAL;
1862 		netif_keep_dst(dev);
1863 	}
1864 	return 0;
1865 }
1866 
1867 /**
1868  * ip6_fb_tnl_dev_init - initializer for fallback tunnel device
1869  *   @dev: fallback device
1870  *
1871  * Return: 0
1872  **/
1873 
1874 static int __net_init ip6_fb_tnl_dev_init(struct net_device *dev)
1875 {
1876 	struct ip6_tnl *t = netdev_priv(dev);
1877 	struct net *net = dev_net(dev);
1878 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1879 
1880 	t->parms.proto = IPPROTO_IPV6;
1881 	dev_hold(dev);
1882 
1883 	rcu_assign_pointer(ip6n->tnls_wc[0], t);
1884 	return 0;
1885 }
1886 
1887 static int ip6_tnl_validate(struct nlattr *tb[], struct nlattr *data[],
1888 			    struct netlink_ext_ack *extack)
1889 {
1890 	u8 proto;
1891 
1892 	if (!data || !data[IFLA_IPTUN_PROTO])
1893 		return 0;
1894 
1895 	proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1896 	if (proto != IPPROTO_IPV6 &&
1897 	    proto != IPPROTO_IPIP &&
1898 	    proto != 0)
1899 		return -EINVAL;
1900 
1901 	return 0;
1902 }
1903 
1904 static void ip6_tnl_netlink_parms(struct nlattr *data[],
1905 				  struct __ip6_tnl_parm *parms)
1906 {
1907 	memset(parms, 0, sizeof(*parms));
1908 
1909 	if (!data)
1910 		return;
1911 
1912 	if (data[IFLA_IPTUN_LINK])
1913 		parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
1914 
1915 	if (data[IFLA_IPTUN_LOCAL])
1916 		parms->laddr = nla_get_in6_addr(data[IFLA_IPTUN_LOCAL]);
1917 
1918 	if (data[IFLA_IPTUN_REMOTE])
1919 		parms->raddr = nla_get_in6_addr(data[IFLA_IPTUN_REMOTE]);
1920 
1921 	if (data[IFLA_IPTUN_TTL])
1922 		parms->hop_limit = nla_get_u8(data[IFLA_IPTUN_TTL]);
1923 
1924 	if (data[IFLA_IPTUN_ENCAP_LIMIT])
1925 		parms->encap_limit = nla_get_u8(data[IFLA_IPTUN_ENCAP_LIMIT]);
1926 
1927 	if (data[IFLA_IPTUN_FLOWINFO])
1928 		parms->flowinfo = nla_get_be32(data[IFLA_IPTUN_FLOWINFO]);
1929 
1930 	if (data[IFLA_IPTUN_FLAGS])
1931 		parms->flags = nla_get_u32(data[IFLA_IPTUN_FLAGS]);
1932 
1933 	if (data[IFLA_IPTUN_PROTO])
1934 		parms->proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1935 
1936 	if (data[IFLA_IPTUN_COLLECT_METADATA])
1937 		parms->collect_md = true;
1938 
1939 	if (data[IFLA_IPTUN_FWMARK])
1940 		parms->fwmark = nla_get_u32(data[IFLA_IPTUN_FWMARK]);
1941 }
1942 
1943 static bool ip6_tnl_netlink_encap_parms(struct nlattr *data[],
1944 					struct ip_tunnel_encap *ipencap)
1945 {
1946 	bool ret = false;
1947 
1948 	memset(ipencap, 0, sizeof(*ipencap));
1949 
1950 	if (!data)
1951 		return ret;
1952 
1953 	if (data[IFLA_IPTUN_ENCAP_TYPE]) {
1954 		ret = true;
1955 		ipencap->type = nla_get_u16(data[IFLA_IPTUN_ENCAP_TYPE]);
1956 	}
1957 
1958 	if (data[IFLA_IPTUN_ENCAP_FLAGS]) {
1959 		ret = true;
1960 		ipencap->flags = nla_get_u16(data[IFLA_IPTUN_ENCAP_FLAGS]);
1961 	}
1962 
1963 	if (data[IFLA_IPTUN_ENCAP_SPORT]) {
1964 		ret = true;
1965 		ipencap->sport = nla_get_be16(data[IFLA_IPTUN_ENCAP_SPORT]);
1966 	}
1967 
1968 	if (data[IFLA_IPTUN_ENCAP_DPORT]) {
1969 		ret = true;
1970 		ipencap->dport = nla_get_be16(data[IFLA_IPTUN_ENCAP_DPORT]);
1971 	}
1972 
1973 	return ret;
1974 }
1975 
1976 static int ip6_tnl_newlink(struct net *src_net, struct net_device *dev,
1977 			   struct nlattr *tb[], struct nlattr *data[],
1978 			   struct netlink_ext_ack *extack)
1979 {
1980 	struct net *net = dev_net(dev);
1981 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1982 	struct ip6_tnl *nt, *t;
1983 	struct ip_tunnel_encap ipencap;
1984 
1985 	nt = netdev_priv(dev);
1986 
1987 	if (ip6_tnl_netlink_encap_parms(data, &ipencap)) {
1988 		int err = ip6_tnl_encap_setup(nt, &ipencap);
1989 
1990 		if (err < 0)
1991 			return err;
1992 	}
1993 
1994 	ip6_tnl_netlink_parms(data, &nt->parms);
1995 
1996 	if (nt->parms.collect_md) {
1997 		if (rtnl_dereference(ip6n->collect_md_tun))
1998 			return -EEXIST;
1999 	} else {
2000 		t = ip6_tnl_locate(net, &nt->parms, 0);
2001 		if (!IS_ERR(t))
2002 			return -EEXIST;
2003 	}
2004 
2005 	return ip6_tnl_create2(dev);
2006 }
2007 
2008 static int ip6_tnl_changelink(struct net_device *dev, struct nlattr *tb[],
2009 			      struct nlattr *data[],
2010 			      struct netlink_ext_ack *extack)
2011 {
2012 	struct ip6_tnl *t = netdev_priv(dev);
2013 	struct __ip6_tnl_parm p;
2014 	struct net *net = t->net;
2015 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2016 	struct ip_tunnel_encap ipencap;
2017 
2018 	if (dev == ip6n->fb_tnl_dev)
2019 		return -EINVAL;
2020 
2021 	if (ip6_tnl_netlink_encap_parms(data, &ipencap)) {
2022 		int err = ip6_tnl_encap_setup(t, &ipencap);
2023 
2024 		if (err < 0)
2025 			return err;
2026 	}
2027 	ip6_tnl_netlink_parms(data, &p);
2028 	if (p.collect_md)
2029 		return -EINVAL;
2030 
2031 	t = ip6_tnl_locate(net, &p, 0);
2032 	if (!IS_ERR(t)) {
2033 		if (t->dev != dev)
2034 			return -EEXIST;
2035 	} else
2036 		t = netdev_priv(dev);
2037 
2038 	return ip6_tnl_update(t, &p);
2039 }
2040 
2041 static void ip6_tnl_dellink(struct net_device *dev, struct list_head *head)
2042 {
2043 	struct net *net = dev_net(dev);
2044 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2045 
2046 	if (dev != ip6n->fb_tnl_dev)
2047 		unregister_netdevice_queue(dev, head);
2048 }
2049 
2050 static size_t ip6_tnl_get_size(const struct net_device *dev)
2051 {
2052 	return
2053 		/* IFLA_IPTUN_LINK */
2054 		nla_total_size(4) +
2055 		/* IFLA_IPTUN_LOCAL */
2056 		nla_total_size(sizeof(struct in6_addr)) +
2057 		/* IFLA_IPTUN_REMOTE */
2058 		nla_total_size(sizeof(struct in6_addr)) +
2059 		/* IFLA_IPTUN_TTL */
2060 		nla_total_size(1) +
2061 		/* IFLA_IPTUN_ENCAP_LIMIT */
2062 		nla_total_size(1) +
2063 		/* IFLA_IPTUN_FLOWINFO */
2064 		nla_total_size(4) +
2065 		/* IFLA_IPTUN_FLAGS */
2066 		nla_total_size(4) +
2067 		/* IFLA_IPTUN_PROTO */
2068 		nla_total_size(1) +
2069 		/* IFLA_IPTUN_ENCAP_TYPE */
2070 		nla_total_size(2) +
2071 		/* IFLA_IPTUN_ENCAP_FLAGS */
2072 		nla_total_size(2) +
2073 		/* IFLA_IPTUN_ENCAP_SPORT */
2074 		nla_total_size(2) +
2075 		/* IFLA_IPTUN_ENCAP_DPORT */
2076 		nla_total_size(2) +
2077 		/* IFLA_IPTUN_COLLECT_METADATA */
2078 		nla_total_size(0) +
2079 		/* IFLA_IPTUN_FWMARK */
2080 		nla_total_size(4) +
2081 		0;
2082 }
2083 
2084 static int ip6_tnl_fill_info(struct sk_buff *skb, const struct net_device *dev)
2085 {
2086 	struct ip6_tnl *tunnel = netdev_priv(dev);
2087 	struct __ip6_tnl_parm *parm = &tunnel->parms;
2088 
2089 	if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
2090 	    nla_put_in6_addr(skb, IFLA_IPTUN_LOCAL, &parm->laddr) ||
2091 	    nla_put_in6_addr(skb, IFLA_IPTUN_REMOTE, &parm->raddr) ||
2092 	    nla_put_u8(skb, IFLA_IPTUN_TTL, parm->hop_limit) ||
2093 	    nla_put_u8(skb, IFLA_IPTUN_ENCAP_LIMIT, parm->encap_limit) ||
2094 	    nla_put_be32(skb, IFLA_IPTUN_FLOWINFO, parm->flowinfo) ||
2095 	    nla_put_u32(skb, IFLA_IPTUN_FLAGS, parm->flags) ||
2096 	    nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->proto) ||
2097 	    nla_put_u32(skb, IFLA_IPTUN_FWMARK, parm->fwmark))
2098 		goto nla_put_failure;
2099 
2100 	if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE, tunnel->encap.type) ||
2101 	    nla_put_be16(skb, IFLA_IPTUN_ENCAP_SPORT, tunnel->encap.sport) ||
2102 	    nla_put_be16(skb, IFLA_IPTUN_ENCAP_DPORT, tunnel->encap.dport) ||
2103 	    nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS, tunnel->encap.flags))
2104 		goto nla_put_failure;
2105 
2106 	if (parm->collect_md)
2107 		if (nla_put_flag(skb, IFLA_IPTUN_COLLECT_METADATA))
2108 			goto nla_put_failure;
2109 
2110 	return 0;
2111 
2112 nla_put_failure:
2113 	return -EMSGSIZE;
2114 }
2115 
2116 struct net *ip6_tnl_get_link_net(const struct net_device *dev)
2117 {
2118 	struct ip6_tnl *tunnel = netdev_priv(dev);
2119 
2120 	return tunnel->net;
2121 }
2122 EXPORT_SYMBOL(ip6_tnl_get_link_net);
2123 
2124 static const struct nla_policy ip6_tnl_policy[IFLA_IPTUN_MAX + 1] = {
2125 	[IFLA_IPTUN_LINK]		= { .type = NLA_U32 },
2126 	[IFLA_IPTUN_LOCAL]		= { .len = sizeof(struct in6_addr) },
2127 	[IFLA_IPTUN_REMOTE]		= { .len = sizeof(struct in6_addr) },
2128 	[IFLA_IPTUN_TTL]		= { .type = NLA_U8 },
2129 	[IFLA_IPTUN_ENCAP_LIMIT]	= { .type = NLA_U8 },
2130 	[IFLA_IPTUN_FLOWINFO]		= { .type = NLA_U32 },
2131 	[IFLA_IPTUN_FLAGS]		= { .type = NLA_U32 },
2132 	[IFLA_IPTUN_PROTO]		= { .type = NLA_U8 },
2133 	[IFLA_IPTUN_ENCAP_TYPE]		= { .type = NLA_U16 },
2134 	[IFLA_IPTUN_ENCAP_FLAGS]	= { .type = NLA_U16 },
2135 	[IFLA_IPTUN_ENCAP_SPORT]	= { .type = NLA_U16 },
2136 	[IFLA_IPTUN_ENCAP_DPORT]	= { .type = NLA_U16 },
2137 	[IFLA_IPTUN_COLLECT_METADATA]	= { .type = NLA_FLAG },
2138 	[IFLA_IPTUN_FWMARK]		= { .type = NLA_U32 },
2139 };
2140 
2141 static struct rtnl_link_ops ip6_link_ops __read_mostly = {
2142 	.kind		= "ip6tnl",
2143 	.maxtype	= IFLA_IPTUN_MAX,
2144 	.policy		= ip6_tnl_policy,
2145 	.priv_size	= sizeof(struct ip6_tnl),
2146 	.setup		= ip6_tnl_dev_setup,
2147 	.validate	= ip6_tnl_validate,
2148 	.newlink	= ip6_tnl_newlink,
2149 	.changelink	= ip6_tnl_changelink,
2150 	.dellink	= ip6_tnl_dellink,
2151 	.get_size	= ip6_tnl_get_size,
2152 	.fill_info	= ip6_tnl_fill_info,
2153 	.get_link_net	= ip6_tnl_get_link_net,
2154 };
2155 
2156 static struct xfrm6_tunnel ip4ip6_handler __read_mostly = {
2157 	.handler	= ip4ip6_rcv,
2158 	.err_handler	= ip4ip6_err,
2159 	.priority	=	1,
2160 };
2161 
2162 static struct xfrm6_tunnel ip6ip6_handler __read_mostly = {
2163 	.handler	= ip6ip6_rcv,
2164 	.err_handler	= ip6ip6_err,
2165 	.priority	=	1,
2166 };
2167 
2168 static void __net_exit ip6_tnl_destroy_tunnels(struct net *net, struct list_head *list)
2169 {
2170 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2171 	struct net_device *dev, *aux;
2172 	int h;
2173 	struct ip6_tnl *t;
2174 
2175 	for_each_netdev_safe(net, dev, aux)
2176 		if (dev->rtnl_link_ops == &ip6_link_ops)
2177 			unregister_netdevice_queue(dev, list);
2178 
2179 	for (h = 0; h < IP6_TUNNEL_HASH_SIZE; h++) {
2180 		t = rtnl_dereference(ip6n->tnls_r_l[h]);
2181 		while (t) {
2182 			/* If dev is in the same netns, it has already
2183 			 * been added to the list by the previous loop.
2184 			 */
2185 			if (!net_eq(dev_net(t->dev), net))
2186 				unregister_netdevice_queue(t->dev, list);
2187 			t = rtnl_dereference(t->next);
2188 		}
2189 	}
2190 }
2191 
2192 static int __net_init ip6_tnl_init_net(struct net *net)
2193 {
2194 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2195 	struct ip6_tnl *t = NULL;
2196 	int err;
2197 
2198 	ip6n->tnls[0] = ip6n->tnls_wc;
2199 	ip6n->tnls[1] = ip6n->tnls_r_l;
2200 
2201 	err = -ENOMEM;
2202 	ip6n->fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6tnl0",
2203 					NET_NAME_UNKNOWN, ip6_tnl_dev_setup);
2204 
2205 	if (!ip6n->fb_tnl_dev)
2206 		goto err_alloc_dev;
2207 	dev_net_set(ip6n->fb_tnl_dev, net);
2208 	ip6n->fb_tnl_dev->rtnl_link_ops = &ip6_link_ops;
2209 	/* FB netdevice is special: we have one, and only one per netns.
2210 	 * Allowing to move it to another netns is clearly unsafe.
2211 	 */
2212 	ip6n->fb_tnl_dev->features |= NETIF_F_NETNS_LOCAL;
2213 
2214 	err = ip6_fb_tnl_dev_init(ip6n->fb_tnl_dev);
2215 	if (err < 0)
2216 		goto err_register;
2217 
2218 	err = register_netdev(ip6n->fb_tnl_dev);
2219 	if (err < 0)
2220 		goto err_register;
2221 
2222 	t = netdev_priv(ip6n->fb_tnl_dev);
2223 
2224 	strcpy(t->parms.name, ip6n->fb_tnl_dev->name);
2225 	return 0;
2226 
2227 err_register:
2228 	free_netdev(ip6n->fb_tnl_dev);
2229 err_alloc_dev:
2230 	return err;
2231 }
2232 
2233 static void __net_exit ip6_tnl_exit_batch_net(struct list_head *net_list)
2234 {
2235 	struct net *net;
2236 	LIST_HEAD(list);
2237 
2238 	rtnl_lock();
2239 	list_for_each_entry(net, net_list, exit_list)
2240 		ip6_tnl_destroy_tunnels(net, &list);
2241 	unregister_netdevice_many(&list);
2242 	rtnl_unlock();
2243 }
2244 
2245 static struct pernet_operations ip6_tnl_net_ops = {
2246 	.init = ip6_tnl_init_net,
2247 	.exit_batch = ip6_tnl_exit_batch_net,
2248 	.id   = &ip6_tnl_net_id,
2249 	.size = sizeof(struct ip6_tnl_net),
2250 };
2251 
2252 /**
2253  * ip6_tunnel_init - register protocol and reserve needed resources
2254  *
2255  * Return: 0 on success
2256  **/
2257 
2258 static int __init ip6_tunnel_init(void)
2259 {
2260 	int  err;
2261 
2262 	if (!ipv6_mod_enabled())
2263 		return -EOPNOTSUPP;
2264 
2265 	err = register_pernet_device(&ip6_tnl_net_ops);
2266 	if (err < 0)
2267 		goto out_pernet;
2268 
2269 	err = xfrm6_tunnel_register(&ip4ip6_handler, AF_INET);
2270 	if (err < 0) {
2271 		pr_err("%s: can't register ip4ip6\n", __func__);
2272 		goto out_ip4ip6;
2273 	}
2274 
2275 	err = xfrm6_tunnel_register(&ip6ip6_handler, AF_INET6);
2276 	if (err < 0) {
2277 		pr_err("%s: can't register ip6ip6\n", __func__);
2278 		goto out_ip6ip6;
2279 	}
2280 	err = rtnl_link_register(&ip6_link_ops);
2281 	if (err < 0)
2282 		goto rtnl_link_failed;
2283 
2284 	return 0;
2285 
2286 rtnl_link_failed:
2287 	xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6);
2288 out_ip6ip6:
2289 	xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET);
2290 out_ip4ip6:
2291 	unregister_pernet_device(&ip6_tnl_net_ops);
2292 out_pernet:
2293 	return err;
2294 }
2295 
2296 /**
2297  * ip6_tunnel_cleanup - free resources and unregister protocol
2298  **/
2299 
2300 static void __exit ip6_tunnel_cleanup(void)
2301 {
2302 	rtnl_link_unregister(&ip6_link_ops);
2303 	if (xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET))
2304 		pr_info("%s: can't deregister ip4ip6\n", __func__);
2305 
2306 	if (xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6))
2307 		pr_info("%s: can't deregister ip6ip6\n", __func__);
2308 
2309 	unregister_pernet_device(&ip6_tnl_net_ops);
2310 }
2311 
2312 module_init(ip6_tunnel_init);
2313 module_exit(ip6_tunnel_cleanup);
2314