xref: /linux/net/ipv6/ip6_tunnel.c (revision 80d443e8876602be2c130f79c4de81e12e2a700d)
1 /*
2  *	IPv6 tunneling device
3  *	Linux INET6 implementation
4  *
5  *	Authors:
6  *	Ville Nuorvala		<vnuorval@tcs.hut.fi>
7  *	Yasuyuki Kozakai	<kozakai@linux-ipv6.org>
8  *
9  *      Based on:
10  *      linux/net/ipv6/sit.c and linux/net/ipv4/ipip.c
11  *
12  *      RFC 2473
13  *
14  *	This program is free software; you can redistribute it and/or
15  *      modify it under the terms of the GNU General Public License
16  *      as published by the Free Software Foundation; either version
17  *      2 of the License, or (at your option) any later version.
18  *
19  */
20 
21 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
22 
23 #include <linux/module.h>
24 #include <linux/capability.h>
25 #include <linux/errno.h>
26 #include <linux/types.h>
27 #include <linux/sockios.h>
28 #include <linux/icmp.h>
29 #include <linux/if.h>
30 #include <linux/in.h>
31 #include <linux/ip.h>
32 #include <linux/net.h>
33 #include <linux/in6.h>
34 #include <linux/netdevice.h>
35 #include <linux/if_arp.h>
36 #include <linux/icmpv6.h>
37 #include <linux/init.h>
38 #include <linux/route.h>
39 #include <linux/rtnetlink.h>
40 #include <linux/netfilter_ipv6.h>
41 #include <linux/slab.h>
42 #include <linux/hash.h>
43 #include <linux/etherdevice.h>
44 
45 #include <linux/uaccess.h>
46 #include <linux/atomic.h>
47 
48 #include <net/icmp.h>
49 #include <net/ip.h>
50 #include <net/ip_tunnels.h>
51 #include <net/ipv6.h>
52 #include <net/ip6_route.h>
53 #include <net/addrconf.h>
54 #include <net/ip6_tunnel.h>
55 #include <net/xfrm.h>
56 #include <net/dsfield.h>
57 #include <net/inet_ecn.h>
58 #include <net/net_namespace.h>
59 #include <net/netns/generic.h>
60 #include <net/dst_metadata.h>
61 
62 MODULE_AUTHOR("Ville Nuorvala");
63 MODULE_DESCRIPTION("IPv6 tunneling device");
64 MODULE_LICENSE("GPL");
65 MODULE_ALIAS_RTNL_LINK("ip6tnl");
66 MODULE_ALIAS_NETDEV("ip6tnl0");
67 
68 #define IP6_TUNNEL_HASH_SIZE_SHIFT  5
69 #define IP6_TUNNEL_HASH_SIZE (1 << IP6_TUNNEL_HASH_SIZE_SHIFT)
70 
71 static bool log_ecn_error = true;
72 module_param(log_ecn_error, bool, 0644);
73 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
74 
75 static u32 HASH(const struct in6_addr *addr1, const struct in6_addr *addr2)
76 {
77 	u32 hash = ipv6_addr_hash(addr1) ^ ipv6_addr_hash(addr2);
78 
79 	return hash_32(hash, IP6_TUNNEL_HASH_SIZE_SHIFT);
80 }
81 
82 static int ip6_tnl_dev_init(struct net_device *dev);
83 static void ip6_tnl_dev_setup(struct net_device *dev);
84 static struct rtnl_link_ops ip6_link_ops __read_mostly;
85 
86 static unsigned int ip6_tnl_net_id __read_mostly;
87 struct ip6_tnl_net {
88 	/* the IPv6 tunnel fallback device */
89 	struct net_device *fb_tnl_dev;
90 	/* lists for storing tunnels in use */
91 	struct ip6_tnl __rcu *tnls_r_l[IP6_TUNNEL_HASH_SIZE];
92 	struct ip6_tnl __rcu *tnls_wc[1];
93 	struct ip6_tnl __rcu **tnls[2];
94 	struct ip6_tnl __rcu *collect_md_tun;
95 };
96 
97 static struct net_device_stats *ip6_get_stats(struct net_device *dev)
98 {
99 	struct pcpu_sw_netstats tmp, sum = { 0 };
100 	int i;
101 
102 	for_each_possible_cpu(i) {
103 		unsigned int start;
104 		const struct pcpu_sw_netstats *tstats =
105 						   per_cpu_ptr(dev->tstats, i);
106 
107 		do {
108 			start = u64_stats_fetch_begin_irq(&tstats->syncp);
109 			tmp.rx_packets = tstats->rx_packets;
110 			tmp.rx_bytes = tstats->rx_bytes;
111 			tmp.tx_packets = tstats->tx_packets;
112 			tmp.tx_bytes =  tstats->tx_bytes;
113 		} while (u64_stats_fetch_retry_irq(&tstats->syncp, start));
114 
115 		sum.rx_packets += tmp.rx_packets;
116 		sum.rx_bytes   += tmp.rx_bytes;
117 		sum.tx_packets += tmp.tx_packets;
118 		sum.tx_bytes   += tmp.tx_bytes;
119 	}
120 	dev->stats.rx_packets = sum.rx_packets;
121 	dev->stats.rx_bytes   = sum.rx_bytes;
122 	dev->stats.tx_packets = sum.tx_packets;
123 	dev->stats.tx_bytes   = sum.tx_bytes;
124 	return &dev->stats;
125 }
126 
127 /**
128  * ip6_tnl_lookup - fetch tunnel matching the end-point addresses
129  *   @remote: the address of the tunnel exit-point
130  *   @local: the address of the tunnel entry-point
131  *
132  * Return:
133  *   tunnel matching given end-points if found,
134  *   else fallback tunnel if its device is up,
135  *   else %NULL
136  **/
137 
138 #define for_each_ip6_tunnel_rcu(start) \
139 	for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
140 
141 static struct ip6_tnl *
142 ip6_tnl_lookup(struct net *net, const struct in6_addr *remote, const struct in6_addr *local)
143 {
144 	unsigned int hash = HASH(remote, local);
145 	struct ip6_tnl *t;
146 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
147 	struct in6_addr any;
148 
149 	for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
150 		if (ipv6_addr_equal(local, &t->parms.laddr) &&
151 		    ipv6_addr_equal(remote, &t->parms.raddr) &&
152 		    (t->dev->flags & IFF_UP))
153 			return t;
154 	}
155 
156 	memset(&any, 0, sizeof(any));
157 	hash = HASH(&any, local);
158 	for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
159 		if (ipv6_addr_equal(local, &t->parms.laddr) &&
160 		    ipv6_addr_any(&t->parms.raddr) &&
161 		    (t->dev->flags & IFF_UP))
162 			return t;
163 	}
164 
165 	hash = HASH(remote, &any);
166 	for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
167 		if (ipv6_addr_equal(remote, &t->parms.raddr) &&
168 		    ipv6_addr_any(&t->parms.laddr) &&
169 		    (t->dev->flags & IFF_UP))
170 			return t;
171 	}
172 
173 	t = rcu_dereference(ip6n->collect_md_tun);
174 	if (t)
175 		return t;
176 
177 	t = rcu_dereference(ip6n->tnls_wc[0]);
178 	if (t && (t->dev->flags & IFF_UP))
179 		return t;
180 
181 	return NULL;
182 }
183 
184 /**
185  * ip6_tnl_bucket - get head of list matching given tunnel parameters
186  *   @p: parameters containing tunnel end-points
187  *
188  * Description:
189  *   ip6_tnl_bucket() returns the head of the list matching the
190  *   &struct in6_addr entries laddr and raddr in @p.
191  *
192  * Return: head of IPv6 tunnel list
193  **/
194 
195 static struct ip6_tnl __rcu **
196 ip6_tnl_bucket(struct ip6_tnl_net *ip6n, const struct __ip6_tnl_parm *p)
197 {
198 	const struct in6_addr *remote = &p->raddr;
199 	const struct in6_addr *local = &p->laddr;
200 	unsigned int h = 0;
201 	int prio = 0;
202 
203 	if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) {
204 		prio = 1;
205 		h = HASH(remote, local);
206 	}
207 	return &ip6n->tnls[prio][h];
208 }
209 
210 /**
211  * ip6_tnl_link - add tunnel to hash table
212  *   @t: tunnel to be added
213  **/
214 
215 static void
216 ip6_tnl_link(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
217 {
218 	struct ip6_tnl __rcu **tp = ip6_tnl_bucket(ip6n, &t->parms);
219 
220 	if (t->parms.collect_md)
221 		rcu_assign_pointer(ip6n->collect_md_tun, t);
222 	rcu_assign_pointer(t->next , rtnl_dereference(*tp));
223 	rcu_assign_pointer(*tp, t);
224 }
225 
226 /**
227  * ip6_tnl_unlink - remove tunnel from hash table
228  *   @t: tunnel to be removed
229  **/
230 
231 static void
232 ip6_tnl_unlink(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
233 {
234 	struct ip6_tnl __rcu **tp;
235 	struct ip6_tnl *iter;
236 
237 	if (t->parms.collect_md)
238 		rcu_assign_pointer(ip6n->collect_md_tun, NULL);
239 
240 	for (tp = ip6_tnl_bucket(ip6n, &t->parms);
241 	     (iter = rtnl_dereference(*tp)) != NULL;
242 	     tp = &iter->next) {
243 		if (t == iter) {
244 			rcu_assign_pointer(*tp, t->next);
245 			break;
246 		}
247 	}
248 }
249 
250 static void ip6_dev_free(struct net_device *dev)
251 {
252 	struct ip6_tnl *t = netdev_priv(dev);
253 
254 	gro_cells_destroy(&t->gro_cells);
255 	dst_cache_destroy(&t->dst_cache);
256 	free_percpu(dev->tstats);
257 	free_netdev(dev);
258 }
259 
260 static int ip6_tnl_create2(struct net_device *dev)
261 {
262 	struct ip6_tnl *t = netdev_priv(dev);
263 	struct net *net = dev_net(dev);
264 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
265 	int err;
266 
267 	t = netdev_priv(dev);
268 
269 	dev->rtnl_link_ops = &ip6_link_ops;
270 	err = register_netdevice(dev);
271 	if (err < 0)
272 		goto out;
273 
274 	strcpy(t->parms.name, dev->name);
275 
276 	dev_hold(dev);
277 	ip6_tnl_link(ip6n, t);
278 	return 0;
279 
280 out:
281 	return err;
282 }
283 
284 /**
285  * ip6_tnl_create - create a new tunnel
286  *   @p: tunnel parameters
287  *   @pt: pointer to new tunnel
288  *
289  * Description:
290  *   Create tunnel matching given parameters.
291  *
292  * Return:
293  *   created tunnel or error pointer
294  **/
295 
296 static struct ip6_tnl *ip6_tnl_create(struct net *net, struct __ip6_tnl_parm *p)
297 {
298 	struct net_device *dev;
299 	struct ip6_tnl *t;
300 	char name[IFNAMSIZ];
301 	int err = -ENOMEM;
302 
303 	if (p->name[0])
304 		strlcpy(name, p->name, IFNAMSIZ);
305 	else
306 		sprintf(name, "ip6tnl%%d");
307 
308 	dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
309 			   ip6_tnl_dev_setup);
310 	if (!dev)
311 		goto failed;
312 
313 	dev_net_set(dev, net);
314 
315 	t = netdev_priv(dev);
316 	t->parms = *p;
317 	t->net = dev_net(dev);
318 	err = ip6_tnl_create2(dev);
319 	if (err < 0)
320 		goto failed_free;
321 
322 	return t;
323 
324 failed_free:
325 	ip6_dev_free(dev);
326 failed:
327 	return ERR_PTR(err);
328 }
329 
330 /**
331  * ip6_tnl_locate - find or create tunnel matching given parameters
332  *   @p: tunnel parameters
333  *   @create: != 0 if allowed to create new tunnel if no match found
334  *
335  * Description:
336  *   ip6_tnl_locate() first tries to locate an existing tunnel
337  *   based on @parms. If this is unsuccessful, but @create is set a new
338  *   tunnel device is created and registered for use.
339  *
340  * Return:
341  *   matching tunnel or error pointer
342  **/
343 
344 static struct ip6_tnl *ip6_tnl_locate(struct net *net,
345 		struct __ip6_tnl_parm *p, int create)
346 {
347 	const struct in6_addr *remote = &p->raddr;
348 	const struct in6_addr *local = &p->laddr;
349 	struct ip6_tnl __rcu **tp;
350 	struct ip6_tnl *t;
351 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
352 
353 	for (tp = ip6_tnl_bucket(ip6n, p);
354 	     (t = rtnl_dereference(*tp)) != NULL;
355 	     tp = &t->next) {
356 		if (ipv6_addr_equal(local, &t->parms.laddr) &&
357 		    ipv6_addr_equal(remote, &t->parms.raddr)) {
358 			if (create)
359 				return ERR_PTR(-EEXIST);
360 
361 			return t;
362 		}
363 	}
364 	if (!create)
365 		return ERR_PTR(-ENODEV);
366 	return ip6_tnl_create(net, p);
367 }
368 
369 /**
370  * ip6_tnl_dev_uninit - tunnel device uninitializer
371  *   @dev: the device to be destroyed
372  *
373  * Description:
374  *   ip6_tnl_dev_uninit() removes tunnel from its list
375  **/
376 
377 static void
378 ip6_tnl_dev_uninit(struct net_device *dev)
379 {
380 	struct ip6_tnl *t = netdev_priv(dev);
381 	struct net *net = t->net;
382 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
383 
384 	if (dev == ip6n->fb_tnl_dev)
385 		RCU_INIT_POINTER(ip6n->tnls_wc[0], NULL);
386 	else
387 		ip6_tnl_unlink(ip6n, t);
388 	dst_cache_reset(&t->dst_cache);
389 	dev_put(dev);
390 }
391 
392 /**
393  * parse_tvl_tnl_enc_lim - handle encapsulation limit option
394  *   @skb: received socket buffer
395  *
396  * Return:
397  *   0 if none was found,
398  *   else index to encapsulation limit
399  **/
400 
401 __u16 ip6_tnl_parse_tlv_enc_lim(struct sk_buff *skb, __u8 *raw)
402 {
403 	const struct ipv6hdr *ipv6h = (const struct ipv6hdr *) raw;
404 	__u8 nexthdr = ipv6h->nexthdr;
405 	__u16 off = sizeof(*ipv6h);
406 
407 	while (ipv6_ext_hdr(nexthdr) && nexthdr != NEXTHDR_NONE) {
408 		__u16 optlen = 0;
409 		struct ipv6_opt_hdr *hdr;
410 		if (raw + off + sizeof(*hdr) > skb->data &&
411 		    !pskb_may_pull(skb, raw - skb->data + off + sizeof (*hdr)))
412 			break;
413 
414 		hdr = (struct ipv6_opt_hdr *) (raw + 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 		if (nexthdr == NEXTHDR_DEST) {
426 			__u16 i = off + 2;
427 			while (1) {
428 				struct ipv6_tlv_tnl_enc_lim *tel;
429 
430 				/* No more room for encapsulation limit */
431 				if (i + sizeof (*tel) > off + optlen)
432 					break;
433 
434 				tel = (struct ipv6_tlv_tnl_enc_lim *) &raw[i];
435 				/* return index of option if found and valid */
436 				if (tel->type == IPV6_TLV_TNL_ENCAP_LIMIT &&
437 				    tel->length == 1)
438 					return i;
439 				/* else jump to next option */
440 				if (tel->type)
441 					i += tel->length + 2;
442 				else
443 					i++;
444 			}
445 		}
446 		nexthdr = hdr->nexthdr;
447 		off += optlen;
448 	}
449 	return 0;
450 }
451 EXPORT_SYMBOL(ip6_tnl_parse_tlv_enc_lim);
452 
453 /**
454  * ip6_tnl_err - tunnel error handler
455  *
456  * Description:
457  *   ip6_tnl_err() should handle errors in the tunnel according
458  *   to the specifications in RFC 2473.
459  **/
460 
461 static int
462 ip6_tnl_err(struct sk_buff *skb, __u8 ipproto, struct inet6_skb_parm *opt,
463 	    u8 *type, u8 *code, int *msg, __u32 *info, int offset)
464 {
465 	const struct ipv6hdr *ipv6h = (const struct ipv6hdr *) skb->data;
466 	struct ip6_tnl *t;
467 	int rel_msg = 0;
468 	u8 rel_type = ICMPV6_DEST_UNREACH;
469 	u8 rel_code = ICMPV6_ADDR_UNREACH;
470 	u8 tproto;
471 	__u32 rel_info = 0;
472 	__u16 len;
473 	int err = -ENOENT;
474 
475 	/* If the packet doesn't contain the original IPv6 header we are
476 	   in trouble since we might need the source address for further
477 	   processing of the error. */
478 
479 	rcu_read_lock();
480 	t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->daddr, &ipv6h->saddr);
481 	if (!t)
482 		goto out;
483 
484 	tproto = ACCESS_ONCE(t->parms.proto);
485 	if (tproto != ipproto && tproto != 0)
486 		goto out;
487 
488 	err = 0;
489 
490 	switch (*type) {
491 		__u32 teli;
492 		struct ipv6_tlv_tnl_enc_lim *tel;
493 		__u32 mtu;
494 	case ICMPV6_DEST_UNREACH:
495 		net_dbg_ratelimited("%s: Path to destination invalid or inactive!\n",
496 				    t->parms.name);
497 		rel_msg = 1;
498 		break;
499 	case ICMPV6_TIME_EXCEED:
500 		if ((*code) == ICMPV6_EXC_HOPLIMIT) {
501 			net_dbg_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
502 					    t->parms.name);
503 			rel_msg = 1;
504 		}
505 		break;
506 	case ICMPV6_PARAMPROB:
507 		teli = 0;
508 		if ((*code) == ICMPV6_HDR_FIELD)
509 			teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
510 
511 		if (teli && teli == *info - 2) {
512 			tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
513 			if (tel->encap_limit == 0) {
514 				net_dbg_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
515 						    t->parms.name);
516 				rel_msg = 1;
517 			}
518 		} else {
519 			net_dbg_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
520 					    t->parms.name);
521 		}
522 		break;
523 	case ICMPV6_PKT_TOOBIG:
524 		mtu = *info - offset;
525 		if (mtu < IPV6_MIN_MTU)
526 			mtu = IPV6_MIN_MTU;
527 		t->dev->mtu = mtu;
528 
529 		len = sizeof(*ipv6h) + ntohs(ipv6h->payload_len);
530 		if (len > mtu) {
531 			rel_type = ICMPV6_PKT_TOOBIG;
532 			rel_code = 0;
533 			rel_info = mtu;
534 			rel_msg = 1;
535 		}
536 		break;
537 	}
538 
539 	*type = rel_type;
540 	*code = rel_code;
541 	*info = rel_info;
542 	*msg = rel_msg;
543 
544 out:
545 	rcu_read_unlock();
546 	return err;
547 }
548 
549 static int
550 ip4ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
551 	   u8 type, u8 code, int offset, __be32 info)
552 {
553 	int rel_msg = 0;
554 	u8 rel_type = type;
555 	u8 rel_code = code;
556 	__u32 rel_info = ntohl(info);
557 	int err;
558 	struct sk_buff *skb2;
559 	const struct iphdr *eiph;
560 	struct rtable *rt;
561 	struct flowi4 fl4;
562 
563 	err = ip6_tnl_err(skb, IPPROTO_IPIP, opt, &rel_type, &rel_code,
564 			  &rel_msg, &rel_info, offset);
565 	if (err < 0)
566 		return err;
567 
568 	if (rel_msg == 0)
569 		return 0;
570 
571 	switch (rel_type) {
572 	case ICMPV6_DEST_UNREACH:
573 		if (rel_code != ICMPV6_ADDR_UNREACH)
574 			return 0;
575 		rel_type = ICMP_DEST_UNREACH;
576 		rel_code = ICMP_HOST_UNREACH;
577 		break;
578 	case ICMPV6_PKT_TOOBIG:
579 		if (rel_code != 0)
580 			return 0;
581 		rel_type = ICMP_DEST_UNREACH;
582 		rel_code = ICMP_FRAG_NEEDED;
583 		break;
584 	case NDISC_REDIRECT:
585 		rel_type = ICMP_REDIRECT;
586 		rel_code = ICMP_REDIR_HOST;
587 	default:
588 		return 0;
589 	}
590 
591 	if (!pskb_may_pull(skb, offset + sizeof(struct iphdr)))
592 		return 0;
593 
594 	skb2 = skb_clone(skb, GFP_ATOMIC);
595 	if (!skb2)
596 		return 0;
597 
598 	skb_dst_drop(skb2);
599 
600 	skb_pull(skb2, offset);
601 	skb_reset_network_header(skb2);
602 	eiph = ip_hdr(skb2);
603 
604 	/* Try to guess incoming interface */
605 	rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL,
606 				   eiph->saddr, 0,
607 				   0, 0,
608 				   IPPROTO_IPIP, RT_TOS(eiph->tos), 0);
609 	if (IS_ERR(rt))
610 		goto out;
611 
612 	skb2->dev = rt->dst.dev;
613 
614 	/* route "incoming" packet */
615 	if (rt->rt_flags & RTCF_LOCAL) {
616 		ip_rt_put(rt);
617 		rt = NULL;
618 		rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL,
619 					   eiph->daddr, eiph->saddr,
620 					   0, 0,
621 					   IPPROTO_IPIP,
622 					   RT_TOS(eiph->tos), 0);
623 		if (IS_ERR(rt) ||
624 		    rt->dst.dev->type != ARPHRD_TUNNEL) {
625 			if (!IS_ERR(rt))
626 				ip_rt_put(rt);
627 			goto out;
628 		}
629 		skb_dst_set(skb2, &rt->dst);
630 	} else {
631 		ip_rt_put(rt);
632 		if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos,
633 				   skb2->dev) ||
634 		    skb_dst(skb2)->dev->type != ARPHRD_TUNNEL)
635 			goto out;
636 	}
637 
638 	/* change mtu on this route */
639 	if (rel_type == ICMP_DEST_UNREACH && rel_code == ICMP_FRAG_NEEDED) {
640 		if (rel_info > dst_mtu(skb_dst(skb2)))
641 			goto out;
642 
643 		skb_dst(skb2)->ops->update_pmtu(skb_dst(skb2), NULL, skb2, rel_info);
644 	}
645 	if (rel_type == ICMP_REDIRECT)
646 		skb_dst(skb2)->ops->redirect(skb_dst(skb2), NULL, skb2);
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 	int rel_msg = 0;
660 	u8 rel_type = type;
661 	u8 rel_code = code;
662 	__u32 rel_info = ntohl(info);
663 	int err;
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 		    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 	kfree_skb(skb);
853 	return 0;
854 }
855 
856 int ip6_tnl_rcv(struct ip6_tnl *t, struct sk_buff *skb,
857 		const struct tnl_ptk_info *tpi,
858 		struct metadata_dst *tun_dst,
859 		bool log_ecn_err)
860 {
861 	return __ip6_tnl_rcv(t, skb, tpi, NULL, ip6ip6_dscp_ecn_decapsulate,
862 			     log_ecn_err);
863 }
864 EXPORT_SYMBOL(ip6_tnl_rcv);
865 
866 static const struct tnl_ptk_info tpi_v6 = {
867 	/* no tunnel info required for ipxip6. */
868 	.proto = htons(ETH_P_IPV6),
869 };
870 
871 static const struct tnl_ptk_info tpi_v4 = {
872 	/* no tunnel info required for ipxip6. */
873 	.proto = htons(ETH_P_IP),
874 };
875 
876 static int ipxip6_rcv(struct sk_buff *skb, u8 ipproto,
877 		      const struct tnl_ptk_info *tpi,
878 		      int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
879 						  const struct ipv6hdr *ipv6h,
880 						  struct sk_buff *skb))
881 {
882 	struct ip6_tnl *t;
883 	const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
884 	struct metadata_dst *tun_dst = NULL;
885 	int ret = -1;
886 
887 	rcu_read_lock();
888 	t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->saddr, &ipv6h->daddr);
889 
890 	if (t) {
891 		u8 tproto = ACCESS_ONCE(t->parms.proto);
892 
893 		if (tproto != ipproto && tproto != 0)
894 			goto drop;
895 		if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
896 			goto drop;
897 		if (!ip6_tnl_rcv_ctl(t, &ipv6h->daddr, &ipv6h->saddr))
898 			goto drop;
899 		if (iptunnel_pull_header(skb, 0, tpi->proto, false))
900 			goto drop;
901 		if (t->parms.collect_md) {
902 			tun_dst = ipv6_tun_rx_dst(skb, 0, 0, 0);
903 			if (!tun_dst)
904 				return 0;
905 		}
906 		ret = __ip6_tnl_rcv(t, skb, tpi, tun_dst, dscp_ecn_decapsulate,
907 				    log_ecn_error);
908 	}
909 
910 	rcu_read_unlock();
911 
912 	return ret;
913 
914 drop:
915 	rcu_read_unlock();
916 	kfree_skb(skb);
917 	return 0;
918 }
919 
920 static int ip4ip6_rcv(struct sk_buff *skb)
921 {
922 	return ipxip6_rcv(skb, IPPROTO_IPIP, &tpi_v4,
923 			  ip4ip6_dscp_ecn_decapsulate);
924 }
925 
926 static int ip6ip6_rcv(struct sk_buff *skb)
927 {
928 	return ipxip6_rcv(skb, IPPROTO_IPV6, &tpi_v6,
929 			  ip6ip6_dscp_ecn_decapsulate);
930 }
931 
932 struct ipv6_tel_txoption {
933 	struct ipv6_txoptions ops;
934 	__u8 dst_opt[8];
935 };
936 
937 static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit)
938 {
939 	memset(opt, 0, sizeof(struct ipv6_tel_txoption));
940 
941 	opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT;
942 	opt->dst_opt[3] = 1;
943 	opt->dst_opt[4] = encap_limit;
944 	opt->dst_opt[5] = IPV6_TLV_PADN;
945 	opt->dst_opt[6] = 1;
946 
947 	opt->ops.dst0opt = (struct ipv6_opt_hdr *) opt->dst_opt;
948 	opt->ops.opt_nflen = 8;
949 }
950 
951 /**
952  * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
953  *   @t: the outgoing tunnel device
954  *   @hdr: IPv6 header from the incoming packet
955  *
956  * Description:
957  *   Avoid trivial tunneling loop by checking that tunnel exit-point
958  *   doesn't match source of incoming packet.
959  *
960  * Return:
961  *   1 if conflict,
962  *   0 else
963  **/
964 
965 static inline bool
966 ip6_tnl_addr_conflict(const struct ip6_tnl *t, const struct ipv6hdr *hdr)
967 {
968 	return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
969 }
970 
971 int ip6_tnl_xmit_ctl(struct ip6_tnl *t,
972 		     const struct in6_addr *laddr,
973 		     const struct in6_addr *raddr)
974 {
975 	struct __ip6_tnl_parm *p = &t->parms;
976 	int ret = 0;
977 	struct net *net = t->net;
978 
979 	if ((p->flags & IP6_TNL_F_CAP_XMIT) ||
980 	    ((p->flags & IP6_TNL_F_CAP_PER_PACKET) &&
981 	     (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_XMIT))) {
982 		struct net_device *ldev = NULL;
983 
984 		rcu_read_lock();
985 		if (p->link)
986 			ldev = dev_get_by_index_rcu(net, p->link);
987 
988 		if (unlikely(!ipv6_chk_addr(net, laddr, ldev, 0)))
989 			pr_warn("%s xmit: Local address not yet configured!\n",
990 				p->name);
991 		else if (!ipv6_addr_is_multicast(raddr) &&
992 			 unlikely(ipv6_chk_addr(net, raddr, NULL, 0)))
993 			pr_warn("%s xmit: Routing loop! Remote address found on this node!\n",
994 				p->name);
995 		else
996 			ret = 1;
997 		rcu_read_unlock();
998 	}
999 	return ret;
1000 }
1001 EXPORT_SYMBOL_GPL(ip6_tnl_xmit_ctl);
1002 
1003 /**
1004  * ip6_tnl_xmit - encapsulate packet and send
1005  *   @skb: the outgoing socket buffer
1006  *   @dev: the outgoing tunnel device
1007  *   @dsfield: dscp code for outer header
1008  *   @fl6: flow of tunneled packet
1009  *   @encap_limit: encapsulation limit
1010  *   @pmtu: Path MTU is stored if packet is too big
1011  *   @proto: next header value
1012  *
1013  * Description:
1014  *   Build new header and do some sanity checks on the packet before sending
1015  *   it.
1016  *
1017  * Return:
1018  *   0 on success
1019  *   -1 fail
1020  *   %-EMSGSIZE message too big. return mtu in this case.
1021  **/
1022 
1023 int ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev, __u8 dsfield,
1024 		 struct flowi6 *fl6, int encap_limit, __u32 *pmtu,
1025 		 __u8 proto)
1026 {
1027 	struct ip6_tnl *t = netdev_priv(dev);
1028 	struct net *net = t->net;
1029 	struct net_device_stats *stats = &t->dev->stats;
1030 	struct ipv6hdr *ipv6h = ipv6_hdr(skb);
1031 	struct ipv6_tel_txoption opt;
1032 	struct dst_entry *dst = NULL, *ndst = NULL;
1033 	struct net_device *tdev;
1034 	int mtu;
1035 	unsigned int psh_hlen = sizeof(struct ipv6hdr) + t->encap_hlen;
1036 	unsigned int max_headroom = psh_hlen;
1037 	bool use_cache = false;
1038 	u8 hop_limit;
1039 	int err = -1;
1040 
1041 	if (t->parms.collect_md) {
1042 		hop_limit = skb_tunnel_info(skb)->key.ttl;
1043 		goto route_lookup;
1044 	} else {
1045 		hop_limit = t->parms.hop_limit;
1046 	}
1047 
1048 	/* NBMA tunnel */
1049 	if (ipv6_addr_any(&t->parms.raddr)) {
1050 		struct in6_addr *addr6;
1051 		struct neighbour *neigh;
1052 		int addr_type;
1053 
1054 		if (!skb_dst(skb))
1055 			goto tx_err_link_failure;
1056 
1057 		neigh = dst_neigh_lookup(skb_dst(skb),
1058 					 &ipv6_hdr(skb)->daddr);
1059 		if (!neigh)
1060 			goto tx_err_link_failure;
1061 
1062 		addr6 = (struct in6_addr *)&neigh->primary_key;
1063 		addr_type = ipv6_addr_type(addr6);
1064 
1065 		if (addr_type == IPV6_ADDR_ANY)
1066 			addr6 = &ipv6_hdr(skb)->daddr;
1067 
1068 		memcpy(&fl6->daddr, addr6, sizeof(fl6->daddr));
1069 		neigh_release(neigh);
1070 	} else if (!(t->parms.flags &
1071 		     (IP6_TNL_F_USE_ORIG_TCLASS | IP6_TNL_F_USE_ORIG_FWMARK))) {
1072 		/* enable the cache only only if the routing decision does
1073 		 * not depend on the current inner header value
1074 		 */
1075 		use_cache = true;
1076 	}
1077 
1078 	if (use_cache)
1079 		dst = dst_cache_get(&t->dst_cache);
1080 
1081 	if (!ip6_tnl_xmit_ctl(t, &fl6->saddr, &fl6->daddr))
1082 		goto tx_err_link_failure;
1083 
1084 	if (!dst) {
1085 route_lookup:
1086 		dst = ip6_route_output(net, NULL, fl6);
1087 
1088 		if (dst->error)
1089 			goto tx_err_link_failure;
1090 		dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), NULL, 0);
1091 		if (IS_ERR(dst)) {
1092 			err = PTR_ERR(dst);
1093 			dst = NULL;
1094 			goto tx_err_link_failure;
1095 		}
1096 		if (t->parms.collect_md &&
1097 		    ipv6_dev_get_saddr(net, ip6_dst_idev(dst)->dev,
1098 				       &fl6->daddr, 0, &fl6->saddr))
1099 			goto tx_err_link_failure;
1100 		ndst = dst;
1101 	}
1102 
1103 	tdev = dst->dev;
1104 
1105 	if (tdev == dev) {
1106 		stats->collisions++;
1107 		net_warn_ratelimited("%s: Local routing loop detected!\n",
1108 				     t->parms.name);
1109 		goto tx_err_dst_release;
1110 	}
1111 	mtu = dst_mtu(dst) - psh_hlen;
1112 	if (encap_limit >= 0) {
1113 		max_headroom += 8;
1114 		mtu -= 8;
1115 	}
1116 	if (mtu < IPV6_MIN_MTU)
1117 		mtu = IPV6_MIN_MTU;
1118 	if (skb_dst(skb) && !t->parms.collect_md)
1119 		skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
1120 	if (skb->len > mtu && !skb_is_gso(skb)) {
1121 		*pmtu = mtu;
1122 		err = -EMSGSIZE;
1123 		goto tx_err_dst_release;
1124 	}
1125 
1126 	if (t->err_count > 0) {
1127 		if (time_before(jiffies,
1128 				t->err_time + IP6TUNNEL_ERR_TIMEO)) {
1129 			t->err_count--;
1130 
1131 			dst_link_failure(skb);
1132 		} else {
1133 			t->err_count = 0;
1134 		}
1135 	}
1136 
1137 	skb_scrub_packet(skb, !net_eq(t->net, dev_net(dev)));
1138 
1139 	/*
1140 	 * Okay, now see if we can stuff it in the buffer as-is.
1141 	 */
1142 	max_headroom += LL_RESERVED_SPACE(tdev);
1143 
1144 	if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
1145 	    (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
1146 		struct sk_buff *new_skb;
1147 
1148 		new_skb = skb_realloc_headroom(skb, max_headroom);
1149 		if (!new_skb)
1150 			goto tx_err_dst_release;
1151 
1152 		if (skb->sk)
1153 			skb_set_owner_w(new_skb, skb->sk);
1154 		consume_skb(skb);
1155 		skb = new_skb;
1156 	}
1157 
1158 	if (t->parms.collect_md) {
1159 		if (t->encap.type != TUNNEL_ENCAP_NONE)
1160 			goto tx_err_dst_release;
1161 	} else {
1162 		if (use_cache && ndst)
1163 			dst_cache_set_ip6(&t->dst_cache, ndst, &fl6->saddr);
1164 	}
1165 	skb_dst_set(skb, dst);
1166 
1167 	if (encap_limit >= 0) {
1168 		init_tel_txopt(&opt, encap_limit);
1169 		ipv6_push_nfrag_opts(skb, &opt.ops, &proto, NULL, NULL);
1170 	}
1171 
1172 	/* Calculate max headroom for all the headers and adjust
1173 	 * needed_headroom if necessary.
1174 	 */
1175 	max_headroom = LL_RESERVED_SPACE(dst->dev) + sizeof(struct ipv6hdr)
1176 			+ dst->header_len + t->hlen;
1177 	if (max_headroom > dev->needed_headroom)
1178 		dev->needed_headroom = max_headroom;
1179 
1180 	err = ip6_tnl_encap(skb, t, &proto, fl6);
1181 	if (err)
1182 		return err;
1183 
1184 	skb_push(skb, sizeof(struct ipv6hdr));
1185 	skb_reset_network_header(skb);
1186 	ipv6h = ipv6_hdr(skb);
1187 	ip6_flow_hdr(ipv6h, INET_ECN_encapsulate(0, dsfield),
1188 		     ip6_make_flowlabel(net, skb, fl6->flowlabel, true, fl6));
1189 	ipv6h->hop_limit = hop_limit;
1190 	ipv6h->nexthdr = proto;
1191 	ipv6h->saddr = fl6->saddr;
1192 	ipv6h->daddr = fl6->daddr;
1193 	ip6tunnel_xmit(NULL, skb, dev);
1194 	return 0;
1195 tx_err_link_failure:
1196 	stats->tx_carrier_errors++;
1197 	dst_link_failure(skb);
1198 tx_err_dst_release:
1199 	dst_release(dst);
1200 	return err;
1201 }
1202 EXPORT_SYMBOL(ip6_tnl_xmit);
1203 
1204 static inline int
1205 ip4ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1206 {
1207 	struct ip6_tnl *t = netdev_priv(dev);
1208 	const struct iphdr  *iph = ip_hdr(skb);
1209 	int encap_limit = -1;
1210 	struct flowi6 fl6;
1211 	__u8 dsfield;
1212 	__u32 mtu;
1213 	u8 tproto;
1214 	int err;
1215 
1216 	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1217 
1218 	tproto = ACCESS_ONCE(t->parms.proto);
1219 	if (tproto != IPPROTO_IPIP && tproto != 0)
1220 		return -1;
1221 
1222 	dsfield = ipv4_get_dsfield(iph);
1223 
1224 	if (t->parms.collect_md) {
1225 		struct ip_tunnel_info *tun_info;
1226 		const struct ip_tunnel_key *key;
1227 
1228 		tun_info = skb_tunnel_info(skb);
1229 		if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
1230 			     ip_tunnel_info_af(tun_info) != AF_INET6))
1231 			return -1;
1232 		key = &tun_info->key;
1233 		memset(&fl6, 0, sizeof(fl6));
1234 		fl6.flowi6_proto = IPPROTO_IPIP;
1235 		fl6.daddr = key->u.ipv6.dst;
1236 		fl6.flowlabel = key->label;
1237 	} else {
1238 		if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1239 			encap_limit = t->parms.encap_limit;
1240 
1241 		memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
1242 		fl6.flowi6_proto = IPPROTO_IPIP;
1243 
1244 		if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1245 			fl6.flowlabel |= htonl((__u32)iph->tos << IPV6_TCLASS_SHIFT)
1246 					 & IPV6_TCLASS_MASK;
1247 		if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
1248 			fl6.flowi6_mark = skb->mark;
1249 	}
1250 
1251 	fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
1252 
1253 	if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP6))
1254 		return -1;
1255 
1256 	skb_set_inner_ipproto(skb, IPPROTO_IPIP);
1257 
1258 	err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
1259 			   IPPROTO_IPIP);
1260 	if (err != 0) {
1261 		/* XXX: send ICMP error even if DF is not set. */
1262 		if (err == -EMSGSIZE)
1263 			icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
1264 				  htonl(mtu));
1265 		return -1;
1266 	}
1267 
1268 	return 0;
1269 }
1270 
1271 static inline int
1272 ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1273 {
1274 	struct ip6_tnl *t = netdev_priv(dev);
1275 	struct ipv6hdr *ipv6h = ipv6_hdr(skb);
1276 	int encap_limit = -1;
1277 	__u16 offset;
1278 	struct flowi6 fl6;
1279 	__u8 dsfield;
1280 	__u32 mtu;
1281 	u8 tproto;
1282 	int err;
1283 
1284 	tproto = ACCESS_ONCE(t->parms.proto);
1285 	if ((tproto != IPPROTO_IPV6 && tproto != 0) ||
1286 	    ip6_tnl_addr_conflict(t, ipv6h))
1287 		return -1;
1288 
1289 	dsfield = ipv6_get_dsfield(ipv6h);
1290 
1291 	if (t->parms.collect_md) {
1292 		struct ip_tunnel_info *tun_info;
1293 		const struct ip_tunnel_key *key;
1294 
1295 		tun_info = skb_tunnel_info(skb);
1296 		if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
1297 			     ip_tunnel_info_af(tun_info) != AF_INET6))
1298 			return -1;
1299 		key = &tun_info->key;
1300 		memset(&fl6, 0, sizeof(fl6));
1301 		fl6.flowi6_proto = IPPROTO_IPV6;
1302 		fl6.daddr = key->u.ipv6.dst;
1303 		fl6.flowlabel = key->label;
1304 	} else {
1305 		offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
1306 		if (offset > 0) {
1307 			struct ipv6_tlv_tnl_enc_lim *tel;
1308 
1309 			tel = (void *)&skb_network_header(skb)[offset];
1310 			if (tel->encap_limit == 0) {
1311 				icmpv6_send(skb, ICMPV6_PARAMPROB,
1312 					    ICMPV6_HDR_FIELD, offset + 2);
1313 				return -1;
1314 			}
1315 			encap_limit = tel->encap_limit - 1;
1316 		} else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) {
1317 			encap_limit = t->parms.encap_limit;
1318 		}
1319 
1320 		memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
1321 		fl6.flowi6_proto = IPPROTO_IPV6;
1322 
1323 		if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1324 			fl6.flowlabel |= (*(__be32 *)ipv6h & IPV6_TCLASS_MASK);
1325 		if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
1326 			fl6.flowlabel |= ip6_flowlabel(ipv6h);
1327 		if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
1328 			fl6.flowi6_mark = skb->mark;
1329 	}
1330 
1331 	fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
1332 
1333 	if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP6))
1334 		return -1;
1335 
1336 	skb_set_inner_ipproto(skb, IPPROTO_IPV6);
1337 
1338 	err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
1339 			   IPPROTO_IPV6);
1340 	if (err != 0) {
1341 		if (err == -EMSGSIZE)
1342 			icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
1343 		return -1;
1344 	}
1345 
1346 	return 0;
1347 }
1348 
1349 static netdev_tx_t
1350 ip6_tnl_start_xmit(struct sk_buff *skb, struct net_device *dev)
1351 {
1352 	struct ip6_tnl *t = netdev_priv(dev);
1353 	struct net_device_stats *stats = &t->dev->stats;
1354 	int ret;
1355 
1356 	switch (skb->protocol) {
1357 	case htons(ETH_P_IP):
1358 		ret = ip4ip6_tnl_xmit(skb, dev);
1359 		break;
1360 	case htons(ETH_P_IPV6):
1361 		ret = ip6ip6_tnl_xmit(skb, dev);
1362 		break;
1363 	default:
1364 		goto tx_err;
1365 	}
1366 
1367 	if (ret < 0)
1368 		goto tx_err;
1369 
1370 	return NETDEV_TX_OK;
1371 
1372 tx_err:
1373 	stats->tx_errors++;
1374 	stats->tx_dropped++;
1375 	kfree_skb(skb);
1376 	return NETDEV_TX_OK;
1377 }
1378 
1379 static void ip6_tnl_link_config(struct ip6_tnl *t)
1380 {
1381 	struct net_device *dev = t->dev;
1382 	struct __ip6_tnl_parm *p = &t->parms;
1383 	struct flowi6 *fl6 = &t->fl.u.ip6;
1384 	int t_hlen;
1385 
1386 	memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
1387 	memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
1388 
1389 	/* Set up flowi template */
1390 	fl6->saddr = p->laddr;
1391 	fl6->daddr = p->raddr;
1392 	fl6->flowi6_oif = p->link;
1393 	fl6->flowlabel = 0;
1394 
1395 	if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
1396 		fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
1397 	if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
1398 		fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
1399 
1400 	p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
1401 	p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
1402 
1403 	if (p->flags&IP6_TNL_F_CAP_XMIT && p->flags&IP6_TNL_F_CAP_RCV)
1404 		dev->flags |= IFF_POINTOPOINT;
1405 	else
1406 		dev->flags &= ~IFF_POINTOPOINT;
1407 
1408 	t->tun_hlen = 0;
1409 	t->hlen = t->encap_hlen + t->tun_hlen;
1410 	t_hlen = t->hlen + sizeof(struct ipv6hdr);
1411 
1412 	if (p->flags & IP6_TNL_F_CAP_XMIT) {
1413 		int strict = (ipv6_addr_type(&p->raddr) &
1414 			      (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
1415 
1416 		struct rt6_info *rt = rt6_lookup(t->net,
1417 						 &p->raddr, &p->laddr,
1418 						 p->link, strict);
1419 
1420 		if (!rt)
1421 			return;
1422 
1423 		if (rt->dst.dev) {
1424 			dev->hard_header_len = rt->dst.dev->hard_header_len +
1425 				t_hlen;
1426 
1427 			dev->mtu = rt->dst.dev->mtu - t_hlen;
1428 			if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1429 				dev->mtu -= 8;
1430 
1431 			if (dev->mtu < IPV6_MIN_MTU)
1432 				dev->mtu = IPV6_MIN_MTU;
1433 		}
1434 		ip6_rt_put(rt);
1435 	}
1436 }
1437 
1438 /**
1439  * ip6_tnl_change - update the tunnel parameters
1440  *   @t: tunnel to be changed
1441  *   @p: tunnel configuration parameters
1442  *
1443  * Description:
1444  *   ip6_tnl_change() updates the tunnel parameters
1445  **/
1446 
1447 static int
1448 ip6_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p)
1449 {
1450 	t->parms.laddr = p->laddr;
1451 	t->parms.raddr = p->raddr;
1452 	t->parms.flags = p->flags;
1453 	t->parms.hop_limit = p->hop_limit;
1454 	t->parms.encap_limit = p->encap_limit;
1455 	t->parms.flowinfo = p->flowinfo;
1456 	t->parms.link = p->link;
1457 	t->parms.proto = p->proto;
1458 	dst_cache_reset(&t->dst_cache);
1459 	ip6_tnl_link_config(t);
1460 	return 0;
1461 }
1462 
1463 static int ip6_tnl_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
1464 {
1465 	struct net *net = t->net;
1466 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1467 	int err;
1468 
1469 	ip6_tnl_unlink(ip6n, t);
1470 	synchronize_net();
1471 	err = ip6_tnl_change(t, p);
1472 	ip6_tnl_link(ip6n, t);
1473 	netdev_state_change(t->dev);
1474 	return err;
1475 }
1476 
1477 static int ip6_tnl0_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
1478 {
1479 	/* for default tnl0 device allow to change only the proto */
1480 	t->parms.proto = p->proto;
1481 	netdev_state_change(t->dev);
1482 	return 0;
1483 }
1484 
1485 static void
1486 ip6_tnl_parm_from_user(struct __ip6_tnl_parm *p, const struct ip6_tnl_parm *u)
1487 {
1488 	p->laddr = u->laddr;
1489 	p->raddr = u->raddr;
1490 	p->flags = u->flags;
1491 	p->hop_limit = u->hop_limit;
1492 	p->encap_limit = u->encap_limit;
1493 	p->flowinfo = u->flowinfo;
1494 	p->link = u->link;
1495 	p->proto = u->proto;
1496 	memcpy(p->name, u->name, sizeof(u->name));
1497 }
1498 
1499 static void
1500 ip6_tnl_parm_to_user(struct ip6_tnl_parm *u, const struct __ip6_tnl_parm *p)
1501 {
1502 	u->laddr = p->laddr;
1503 	u->raddr = p->raddr;
1504 	u->flags = p->flags;
1505 	u->hop_limit = p->hop_limit;
1506 	u->encap_limit = p->encap_limit;
1507 	u->flowinfo = p->flowinfo;
1508 	u->link = p->link;
1509 	u->proto = p->proto;
1510 	memcpy(u->name, p->name, sizeof(u->name));
1511 }
1512 
1513 /**
1514  * ip6_tnl_ioctl - configure ipv6 tunnels from userspace
1515  *   @dev: virtual device associated with tunnel
1516  *   @ifr: parameters passed from userspace
1517  *   @cmd: command to be performed
1518  *
1519  * Description:
1520  *   ip6_tnl_ioctl() is used for managing IPv6 tunnels
1521  *   from userspace.
1522  *
1523  *   The possible commands are the following:
1524  *     %SIOCGETTUNNEL: get tunnel parameters for device
1525  *     %SIOCADDTUNNEL: add tunnel matching given tunnel parameters
1526  *     %SIOCCHGTUNNEL: change tunnel parameters to those given
1527  *     %SIOCDELTUNNEL: delete tunnel
1528  *
1529  *   The fallback device "ip6tnl0", created during module
1530  *   initialization, can be used for creating other tunnel devices.
1531  *
1532  * Return:
1533  *   0 on success,
1534  *   %-EFAULT if unable to copy data to or from userspace,
1535  *   %-EPERM if current process hasn't %CAP_NET_ADMIN set
1536  *   %-EINVAL if passed tunnel parameters are invalid,
1537  *   %-EEXIST if changing a tunnel's parameters would cause a conflict
1538  *   %-ENODEV if attempting to change or delete a nonexisting device
1539  **/
1540 
1541 static int
1542 ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1543 {
1544 	int err = 0;
1545 	struct ip6_tnl_parm p;
1546 	struct __ip6_tnl_parm p1;
1547 	struct ip6_tnl *t = netdev_priv(dev);
1548 	struct net *net = t->net;
1549 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1550 
1551 	memset(&p1, 0, sizeof(p1));
1552 
1553 	switch (cmd) {
1554 	case SIOCGETTUNNEL:
1555 		if (dev == ip6n->fb_tnl_dev) {
1556 			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1557 				err = -EFAULT;
1558 				break;
1559 			}
1560 			ip6_tnl_parm_from_user(&p1, &p);
1561 			t = ip6_tnl_locate(net, &p1, 0);
1562 			if (IS_ERR(t))
1563 				t = netdev_priv(dev);
1564 		} else {
1565 			memset(&p, 0, sizeof(p));
1566 		}
1567 		ip6_tnl_parm_to_user(&p, &t->parms);
1568 		if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) {
1569 			err = -EFAULT;
1570 		}
1571 		break;
1572 	case SIOCADDTUNNEL:
1573 	case SIOCCHGTUNNEL:
1574 		err = -EPERM;
1575 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1576 			break;
1577 		err = -EFAULT;
1578 		if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1579 			break;
1580 		err = -EINVAL;
1581 		if (p.proto != IPPROTO_IPV6 && p.proto != IPPROTO_IPIP &&
1582 		    p.proto != 0)
1583 			break;
1584 		ip6_tnl_parm_from_user(&p1, &p);
1585 		t = ip6_tnl_locate(net, &p1, cmd == SIOCADDTUNNEL);
1586 		if (cmd == SIOCCHGTUNNEL) {
1587 			if (!IS_ERR(t)) {
1588 				if (t->dev != dev) {
1589 					err = -EEXIST;
1590 					break;
1591 				}
1592 			} else
1593 				t = netdev_priv(dev);
1594 			if (dev == ip6n->fb_tnl_dev)
1595 				err = ip6_tnl0_update(t, &p1);
1596 			else
1597 				err = ip6_tnl_update(t, &p1);
1598 		}
1599 		if (!IS_ERR(t)) {
1600 			err = 0;
1601 			ip6_tnl_parm_to_user(&p, &t->parms);
1602 			if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1603 				err = -EFAULT;
1604 
1605 		} else {
1606 			err = PTR_ERR(t);
1607 		}
1608 		break;
1609 	case SIOCDELTUNNEL:
1610 		err = -EPERM;
1611 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1612 			break;
1613 
1614 		if (dev == ip6n->fb_tnl_dev) {
1615 			err = -EFAULT;
1616 			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1617 				break;
1618 			err = -ENOENT;
1619 			ip6_tnl_parm_from_user(&p1, &p);
1620 			t = ip6_tnl_locate(net, &p1, 0);
1621 			if (IS_ERR(t))
1622 				break;
1623 			err = -EPERM;
1624 			if (t->dev == ip6n->fb_tnl_dev)
1625 				break;
1626 			dev = t->dev;
1627 		}
1628 		err = 0;
1629 		unregister_netdevice(dev);
1630 		break;
1631 	default:
1632 		err = -EINVAL;
1633 	}
1634 	return err;
1635 }
1636 
1637 /**
1638  * ip6_tnl_change_mtu - change mtu manually for tunnel device
1639  *   @dev: virtual device associated with tunnel
1640  *   @new_mtu: the new mtu
1641  *
1642  * Return:
1643  *   0 on success,
1644  *   %-EINVAL if mtu too small
1645  **/
1646 
1647 int ip6_tnl_change_mtu(struct net_device *dev, int new_mtu)
1648 {
1649 	struct ip6_tnl *tnl = netdev_priv(dev);
1650 
1651 	if (tnl->parms.proto == IPPROTO_IPIP) {
1652 		if (new_mtu < ETH_MIN_MTU)
1653 			return -EINVAL;
1654 	} else {
1655 		if (new_mtu < IPV6_MIN_MTU)
1656 			return -EINVAL;
1657 	}
1658 	if (new_mtu > 0xFFF8 - dev->hard_header_len)
1659 		return -EINVAL;
1660 	dev->mtu = new_mtu;
1661 	return 0;
1662 }
1663 EXPORT_SYMBOL(ip6_tnl_change_mtu);
1664 
1665 int ip6_tnl_get_iflink(const struct net_device *dev)
1666 {
1667 	struct ip6_tnl *t = netdev_priv(dev);
1668 
1669 	return t->parms.link;
1670 }
1671 EXPORT_SYMBOL(ip6_tnl_get_iflink);
1672 
1673 int ip6_tnl_encap_add_ops(const struct ip6_tnl_encap_ops *ops,
1674 			  unsigned int num)
1675 {
1676 	if (num >= MAX_IPTUN_ENCAP_OPS)
1677 		return -ERANGE;
1678 
1679 	return !cmpxchg((const struct ip6_tnl_encap_ops **)
1680 			&ip6tun_encaps[num],
1681 			NULL, ops) ? 0 : -1;
1682 }
1683 EXPORT_SYMBOL(ip6_tnl_encap_add_ops);
1684 
1685 int ip6_tnl_encap_del_ops(const struct ip6_tnl_encap_ops *ops,
1686 			  unsigned int num)
1687 {
1688 	int ret;
1689 
1690 	if (num >= MAX_IPTUN_ENCAP_OPS)
1691 		return -ERANGE;
1692 
1693 	ret = (cmpxchg((const struct ip6_tnl_encap_ops **)
1694 		       &ip6tun_encaps[num],
1695 		       ops, NULL) == ops) ? 0 : -1;
1696 
1697 	synchronize_net();
1698 
1699 	return ret;
1700 }
1701 EXPORT_SYMBOL(ip6_tnl_encap_del_ops);
1702 
1703 int ip6_tnl_encap_setup(struct ip6_tnl *t,
1704 			struct ip_tunnel_encap *ipencap)
1705 {
1706 	int hlen;
1707 
1708 	memset(&t->encap, 0, sizeof(t->encap));
1709 
1710 	hlen = ip6_encap_hlen(ipencap);
1711 	if (hlen < 0)
1712 		return hlen;
1713 
1714 	t->encap.type = ipencap->type;
1715 	t->encap.sport = ipencap->sport;
1716 	t->encap.dport = ipencap->dport;
1717 	t->encap.flags = ipencap->flags;
1718 
1719 	t->encap_hlen = hlen;
1720 	t->hlen = t->encap_hlen + t->tun_hlen;
1721 
1722 	return 0;
1723 }
1724 EXPORT_SYMBOL_GPL(ip6_tnl_encap_setup);
1725 
1726 static const struct net_device_ops ip6_tnl_netdev_ops = {
1727 	.ndo_init	= ip6_tnl_dev_init,
1728 	.ndo_uninit	= ip6_tnl_dev_uninit,
1729 	.ndo_start_xmit = ip6_tnl_start_xmit,
1730 	.ndo_do_ioctl	= ip6_tnl_ioctl,
1731 	.ndo_change_mtu = ip6_tnl_change_mtu,
1732 	.ndo_get_stats	= ip6_get_stats,
1733 	.ndo_get_iflink = ip6_tnl_get_iflink,
1734 };
1735 
1736 #define IPXIPX_FEATURES (NETIF_F_SG |		\
1737 			 NETIF_F_FRAGLIST |	\
1738 			 NETIF_F_HIGHDMA |	\
1739 			 NETIF_F_GSO_SOFTWARE |	\
1740 			 NETIF_F_HW_CSUM)
1741 
1742 /**
1743  * ip6_tnl_dev_setup - setup virtual tunnel device
1744  *   @dev: virtual device associated with tunnel
1745  *
1746  * Description:
1747  *   Initialize function pointers and device parameters
1748  **/
1749 
1750 static void ip6_tnl_dev_setup(struct net_device *dev)
1751 {
1752 	dev->netdev_ops = &ip6_tnl_netdev_ops;
1753 	dev->destructor = ip6_dev_free;
1754 
1755 	dev->type = ARPHRD_TUNNEL6;
1756 	dev->flags |= IFF_NOARP;
1757 	dev->addr_len = sizeof(struct in6_addr);
1758 	dev->features |= NETIF_F_LLTX;
1759 	netif_keep_dst(dev);
1760 
1761 	dev->features		|= IPXIPX_FEATURES;
1762 	dev->hw_features	|= IPXIPX_FEATURES;
1763 
1764 	/* This perm addr will be used as interface identifier by IPv6 */
1765 	dev->addr_assign_type = NET_ADDR_RANDOM;
1766 	eth_random_addr(dev->perm_addr);
1767 }
1768 
1769 
1770 /**
1771  * ip6_tnl_dev_init_gen - general initializer for all tunnel devices
1772  *   @dev: virtual device associated with tunnel
1773  **/
1774 
1775 static inline int
1776 ip6_tnl_dev_init_gen(struct net_device *dev)
1777 {
1778 	struct ip6_tnl *t = netdev_priv(dev);
1779 	int ret;
1780 	int t_hlen;
1781 
1782 	t->dev = dev;
1783 	t->net = dev_net(dev);
1784 	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1785 	if (!dev->tstats)
1786 		return -ENOMEM;
1787 
1788 	ret = dst_cache_init(&t->dst_cache, GFP_KERNEL);
1789 	if (ret)
1790 		goto free_stats;
1791 
1792 	ret = gro_cells_init(&t->gro_cells, dev);
1793 	if (ret)
1794 		goto destroy_dst;
1795 
1796 	t->tun_hlen = 0;
1797 	t->hlen = t->encap_hlen + t->tun_hlen;
1798 	t_hlen = t->hlen + sizeof(struct ipv6hdr);
1799 
1800 	dev->type = ARPHRD_TUNNEL6;
1801 	dev->hard_header_len = LL_MAX_HEADER + t_hlen;
1802 	dev->mtu = ETH_DATA_LEN - t_hlen;
1803 	if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1804 		dev->mtu -= 8;
1805 	dev->min_mtu = ETH_MIN_MTU;
1806 	dev->max_mtu = 0xFFF8 - dev->hard_header_len;
1807 
1808 	return 0;
1809 
1810 destroy_dst:
1811 	dst_cache_destroy(&t->dst_cache);
1812 free_stats:
1813 	free_percpu(dev->tstats);
1814 	dev->tstats = NULL;
1815 
1816 	return ret;
1817 }
1818 
1819 /**
1820  * ip6_tnl_dev_init - initializer for all non fallback tunnel devices
1821  *   @dev: virtual device associated with tunnel
1822  **/
1823 
1824 static int ip6_tnl_dev_init(struct net_device *dev)
1825 {
1826 	struct ip6_tnl *t = netdev_priv(dev);
1827 	int err = ip6_tnl_dev_init_gen(dev);
1828 
1829 	if (err)
1830 		return err;
1831 	ip6_tnl_link_config(t);
1832 	if (t->parms.collect_md) {
1833 		dev->features |= NETIF_F_NETNS_LOCAL;
1834 		netif_keep_dst(dev);
1835 	}
1836 	return 0;
1837 }
1838 
1839 /**
1840  * ip6_fb_tnl_dev_init - initializer for fallback tunnel device
1841  *   @dev: fallback device
1842  *
1843  * Return: 0
1844  **/
1845 
1846 static int __net_init ip6_fb_tnl_dev_init(struct net_device *dev)
1847 {
1848 	struct ip6_tnl *t = netdev_priv(dev);
1849 	struct net *net = dev_net(dev);
1850 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1851 
1852 	t->parms.proto = IPPROTO_IPV6;
1853 	dev_hold(dev);
1854 
1855 	rcu_assign_pointer(ip6n->tnls_wc[0], t);
1856 	return 0;
1857 }
1858 
1859 static int ip6_tnl_validate(struct nlattr *tb[], struct nlattr *data[])
1860 {
1861 	u8 proto;
1862 
1863 	if (!data || !data[IFLA_IPTUN_PROTO])
1864 		return 0;
1865 
1866 	proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1867 	if (proto != IPPROTO_IPV6 &&
1868 	    proto != IPPROTO_IPIP &&
1869 	    proto != 0)
1870 		return -EINVAL;
1871 
1872 	return 0;
1873 }
1874 
1875 static void ip6_tnl_netlink_parms(struct nlattr *data[],
1876 				  struct __ip6_tnl_parm *parms)
1877 {
1878 	memset(parms, 0, sizeof(*parms));
1879 
1880 	if (!data)
1881 		return;
1882 
1883 	if (data[IFLA_IPTUN_LINK])
1884 		parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
1885 
1886 	if (data[IFLA_IPTUN_LOCAL])
1887 		parms->laddr = nla_get_in6_addr(data[IFLA_IPTUN_LOCAL]);
1888 
1889 	if (data[IFLA_IPTUN_REMOTE])
1890 		parms->raddr = nla_get_in6_addr(data[IFLA_IPTUN_REMOTE]);
1891 
1892 	if (data[IFLA_IPTUN_TTL])
1893 		parms->hop_limit = nla_get_u8(data[IFLA_IPTUN_TTL]);
1894 
1895 	if (data[IFLA_IPTUN_ENCAP_LIMIT])
1896 		parms->encap_limit = nla_get_u8(data[IFLA_IPTUN_ENCAP_LIMIT]);
1897 
1898 	if (data[IFLA_IPTUN_FLOWINFO])
1899 		parms->flowinfo = nla_get_be32(data[IFLA_IPTUN_FLOWINFO]);
1900 
1901 	if (data[IFLA_IPTUN_FLAGS])
1902 		parms->flags = nla_get_u32(data[IFLA_IPTUN_FLAGS]);
1903 
1904 	if (data[IFLA_IPTUN_PROTO])
1905 		parms->proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1906 
1907 	if (data[IFLA_IPTUN_COLLECT_METADATA])
1908 		parms->collect_md = true;
1909 }
1910 
1911 static bool ip6_tnl_netlink_encap_parms(struct nlattr *data[],
1912 					struct ip_tunnel_encap *ipencap)
1913 {
1914 	bool ret = false;
1915 
1916 	memset(ipencap, 0, sizeof(*ipencap));
1917 
1918 	if (!data)
1919 		return ret;
1920 
1921 	if (data[IFLA_IPTUN_ENCAP_TYPE]) {
1922 		ret = true;
1923 		ipencap->type = nla_get_u16(data[IFLA_IPTUN_ENCAP_TYPE]);
1924 	}
1925 
1926 	if (data[IFLA_IPTUN_ENCAP_FLAGS]) {
1927 		ret = true;
1928 		ipencap->flags = nla_get_u16(data[IFLA_IPTUN_ENCAP_FLAGS]);
1929 	}
1930 
1931 	if (data[IFLA_IPTUN_ENCAP_SPORT]) {
1932 		ret = true;
1933 		ipencap->sport = nla_get_be16(data[IFLA_IPTUN_ENCAP_SPORT]);
1934 	}
1935 
1936 	if (data[IFLA_IPTUN_ENCAP_DPORT]) {
1937 		ret = true;
1938 		ipencap->dport = nla_get_be16(data[IFLA_IPTUN_ENCAP_DPORT]);
1939 	}
1940 
1941 	return ret;
1942 }
1943 
1944 static int ip6_tnl_newlink(struct net *src_net, struct net_device *dev,
1945 			   struct nlattr *tb[], struct nlattr *data[])
1946 {
1947 	struct net *net = dev_net(dev);
1948 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1949 	struct ip6_tnl *nt, *t;
1950 	struct ip_tunnel_encap ipencap;
1951 
1952 	nt = netdev_priv(dev);
1953 
1954 	if (ip6_tnl_netlink_encap_parms(data, &ipencap)) {
1955 		int err = ip6_tnl_encap_setup(nt, &ipencap);
1956 
1957 		if (err < 0)
1958 			return err;
1959 	}
1960 
1961 	ip6_tnl_netlink_parms(data, &nt->parms);
1962 
1963 	if (nt->parms.collect_md) {
1964 		if (rtnl_dereference(ip6n->collect_md_tun))
1965 			return -EEXIST;
1966 	} else {
1967 		t = ip6_tnl_locate(net, &nt->parms, 0);
1968 		if (!IS_ERR(t))
1969 			return -EEXIST;
1970 	}
1971 
1972 	return ip6_tnl_create2(dev);
1973 }
1974 
1975 static int ip6_tnl_changelink(struct net_device *dev, struct nlattr *tb[],
1976 			      struct nlattr *data[])
1977 {
1978 	struct ip6_tnl *t = netdev_priv(dev);
1979 	struct __ip6_tnl_parm p;
1980 	struct net *net = t->net;
1981 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1982 	struct ip_tunnel_encap ipencap;
1983 
1984 	if (dev == ip6n->fb_tnl_dev)
1985 		return -EINVAL;
1986 
1987 	if (ip6_tnl_netlink_encap_parms(data, &ipencap)) {
1988 		int err = ip6_tnl_encap_setup(t, &ipencap);
1989 
1990 		if (err < 0)
1991 			return err;
1992 	}
1993 	ip6_tnl_netlink_parms(data, &p);
1994 	if (p.collect_md)
1995 		return -EINVAL;
1996 
1997 	t = ip6_tnl_locate(net, &p, 0);
1998 	if (!IS_ERR(t)) {
1999 		if (t->dev != dev)
2000 			return -EEXIST;
2001 	} else
2002 		t = netdev_priv(dev);
2003 
2004 	return ip6_tnl_update(t, &p);
2005 }
2006 
2007 static void ip6_tnl_dellink(struct net_device *dev, struct list_head *head)
2008 {
2009 	struct net *net = dev_net(dev);
2010 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2011 
2012 	if (dev != ip6n->fb_tnl_dev)
2013 		unregister_netdevice_queue(dev, head);
2014 }
2015 
2016 static size_t ip6_tnl_get_size(const struct net_device *dev)
2017 {
2018 	return
2019 		/* IFLA_IPTUN_LINK */
2020 		nla_total_size(4) +
2021 		/* IFLA_IPTUN_LOCAL */
2022 		nla_total_size(sizeof(struct in6_addr)) +
2023 		/* IFLA_IPTUN_REMOTE */
2024 		nla_total_size(sizeof(struct in6_addr)) +
2025 		/* IFLA_IPTUN_TTL */
2026 		nla_total_size(1) +
2027 		/* IFLA_IPTUN_ENCAP_LIMIT */
2028 		nla_total_size(1) +
2029 		/* IFLA_IPTUN_FLOWINFO */
2030 		nla_total_size(4) +
2031 		/* IFLA_IPTUN_FLAGS */
2032 		nla_total_size(4) +
2033 		/* IFLA_IPTUN_PROTO */
2034 		nla_total_size(1) +
2035 		/* IFLA_IPTUN_ENCAP_TYPE */
2036 		nla_total_size(2) +
2037 		/* IFLA_IPTUN_ENCAP_FLAGS */
2038 		nla_total_size(2) +
2039 		/* IFLA_IPTUN_ENCAP_SPORT */
2040 		nla_total_size(2) +
2041 		/* IFLA_IPTUN_ENCAP_DPORT */
2042 		nla_total_size(2) +
2043 		/* IFLA_IPTUN_COLLECT_METADATA */
2044 		nla_total_size(0) +
2045 		0;
2046 }
2047 
2048 static int ip6_tnl_fill_info(struct sk_buff *skb, const struct net_device *dev)
2049 {
2050 	struct ip6_tnl *tunnel = netdev_priv(dev);
2051 	struct __ip6_tnl_parm *parm = &tunnel->parms;
2052 
2053 	if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
2054 	    nla_put_in6_addr(skb, IFLA_IPTUN_LOCAL, &parm->laddr) ||
2055 	    nla_put_in6_addr(skb, IFLA_IPTUN_REMOTE, &parm->raddr) ||
2056 	    nla_put_u8(skb, IFLA_IPTUN_TTL, parm->hop_limit) ||
2057 	    nla_put_u8(skb, IFLA_IPTUN_ENCAP_LIMIT, parm->encap_limit) ||
2058 	    nla_put_be32(skb, IFLA_IPTUN_FLOWINFO, parm->flowinfo) ||
2059 	    nla_put_u32(skb, IFLA_IPTUN_FLAGS, parm->flags) ||
2060 	    nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->proto))
2061 		goto nla_put_failure;
2062 
2063 	if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE, tunnel->encap.type) ||
2064 	    nla_put_be16(skb, IFLA_IPTUN_ENCAP_SPORT, tunnel->encap.sport) ||
2065 	    nla_put_be16(skb, IFLA_IPTUN_ENCAP_DPORT, tunnel->encap.dport) ||
2066 	    nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS, tunnel->encap.flags))
2067 		goto nla_put_failure;
2068 
2069 	if (parm->collect_md)
2070 		if (nla_put_flag(skb, IFLA_IPTUN_COLLECT_METADATA))
2071 			goto nla_put_failure;
2072 	return 0;
2073 
2074 nla_put_failure:
2075 	return -EMSGSIZE;
2076 }
2077 
2078 struct net *ip6_tnl_get_link_net(const struct net_device *dev)
2079 {
2080 	struct ip6_tnl *tunnel = netdev_priv(dev);
2081 
2082 	return tunnel->net;
2083 }
2084 EXPORT_SYMBOL(ip6_tnl_get_link_net);
2085 
2086 static const struct nla_policy ip6_tnl_policy[IFLA_IPTUN_MAX + 1] = {
2087 	[IFLA_IPTUN_LINK]		= { .type = NLA_U32 },
2088 	[IFLA_IPTUN_LOCAL]		= { .len = sizeof(struct in6_addr) },
2089 	[IFLA_IPTUN_REMOTE]		= { .len = sizeof(struct in6_addr) },
2090 	[IFLA_IPTUN_TTL]		= { .type = NLA_U8 },
2091 	[IFLA_IPTUN_ENCAP_LIMIT]	= { .type = NLA_U8 },
2092 	[IFLA_IPTUN_FLOWINFO]		= { .type = NLA_U32 },
2093 	[IFLA_IPTUN_FLAGS]		= { .type = NLA_U32 },
2094 	[IFLA_IPTUN_PROTO]		= { .type = NLA_U8 },
2095 	[IFLA_IPTUN_ENCAP_TYPE]		= { .type = NLA_U16 },
2096 	[IFLA_IPTUN_ENCAP_FLAGS]	= { .type = NLA_U16 },
2097 	[IFLA_IPTUN_ENCAP_SPORT]	= { .type = NLA_U16 },
2098 	[IFLA_IPTUN_ENCAP_DPORT]	= { .type = NLA_U16 },
2099 	[IFLA_IPTUN_COLLECT_METADATA]	= { .type = NLA_FLAG },
2100 };
2101 
2102 static struct rtnl_link_ops ip6_link_ops __read_mostly = {
2103 	.kind		= "ip6tnl",
2104 	.maxtype	= IFLA_IPTUN_MAX,
2105 	.policy		= ip6_tnl_policy,
2106 	.priv_size	= sizeof(struct ip6_tnl),
2107 	.setup		= ip6_tnl_dev_setup,
2108 	.validate	= ip6_tnl_validate,
2109 	.newlink	= ip6_tnl_newlink,
2110 	.changelink	= ip6_tnl_changelink,
2111 	.dellink	= ip6_tnl_dellink,
2112 	.get_size	= ip6_tnl_get_size,
2113 	.fill_info	= ip6_tnl_fill_info,
2114 	.get_link_net	= ip6_tnl_get_link_net,
2115 };
2116 
2117 static struct xfrm6_tunnel ip4ip6_handler __read_mostly = {
2118 	.handler	= ip4ip6_rcv,
2119 	.err_handler	= ip4ip6_err,
2120 	.priority	=	1,
2121 };
2122 
2123 static struct xfrm6_tunnel ip6ip6_handler __read_mostly = {
2124 	.handler	= ip6ip6_rcv,
2125 	.err_handler	= ip6ip6_err,
2126 	.priority	=	1,
2127 };
2128 
2129 static void __net_exit ip6_tnl_destroy_tunnels(struct net *net)
2130 {
2131 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2132 	struct net_device *dev, *aux;
2133 	int h;
2134 	struct ip6_tnl *t;
2135 	LIST_HEAD(list);
2136 
2137 	for_each_netdev_safe(net, dev, aux)
2138 		if (dev->rtnl_link_ops == &ip6_link_ops)
2139 			unregister_netdevice_queue(dev, &list);
2140 
2141 	for (h = 0; h < IP6_TUNNEL_HASH_SIZE; h++) {
2142 		t = rtnl_dereference(ip6n->tnls_r_l[h]);
2143 		while (t) {
2144 			/* If dev is in the same netns, it has already
2145 			 * been added to the list by the previous loop.
2146 			 */
2147 			if (!net_eq(dev_net(t->dev), net))
2148 				unregister_netdevice_queue(t->dev, &list);
2149 			t = rtnl_dereference(t->next);
2150 		}
2151 	}
2152 
2153 	unregister_netdevice_many(&list);
2154 }
2155 
2156 static int __net_init ip6_tnl_init_net(struct net *net)
2157 {
2158 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2159 	struct ip6_tnl *t = NULL;
2160 	int err;
2161 
2162 	ip6n->tnls[0] = ip6n->tnls_wc;
2163 	ip6n->tnls[1] = ip6n->tnls_r_l;
2164 
2165 	err = -ENOMEM;
2166 	ip6n->fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6tnl0",
2167 					NET_NAME_UNKNOWN, ip6_tnl_dev_setup);
2168 
2169 	if (!ip6n->fb_tnl_dev)
2170 		goto err_alloc_dev;
2171 	dev_net_set(ip6n->fb_tnl_dev, net);
2172 	ip6n->fb_tnl_dev->rtnl_link_ops = &ip6_link_ops;
2173 	/* FB netdevice is special: we have one, and only one per netns.
2174 	 * Allowing to move it to another netns is clearly unsafe.
2175 	 */
2176 	ip6n->fb_tnl_dev->features |= NETIF_F_NETNS_LOCAL;
2177 
2178 	err = ip6_fb_tnl_dev_init(ip6n->fb_tnl_dev);
2179 	if (err < 0)
2180 		goto err_register;
2181 
2182 	err = register_netdev(ip6n->fb_tnl_dev);
2183 	if (err < 0)
2184 		goto err_register;
2185 
2186 	t = netdev_priv(ip6n->fb_tnl_dev);
2187 
2188 	strcpy(t->parms.name, ip6n->fb_tnl_dev->name);
2189 	return 0;
2190 
2191 err_register:
2192 	ip6_dev_free(ip6n->fb_tnl_dev);
2193 err_alloc_dev:
2194 	return err;
2195 }
2196 
2197 static void __net_exit ip6_tnl_exit_net(struct net *net)
2198 {
2199 	rtnl_lock();
2200 	ip6_tnl_destroy_tunnels(net);
2201 	rtnl_unlock();
2202 }
2203 
2204 static struct pernet_operations ip6_tnl_net_ops = {
2205 	.init = ip6_tnl_init_net,
2206 	.exit = ip6_tnl_exit_net,
2207 	.id   = &ip6_tnl_net_id,
2208 	.size = sizeof(struct ip6_tnl_net),
2209 };
2210 
2211 /**
2212  * ip6_tunnel_init - register protocol and reserve needed resources
2213  *
2214  * Return: 0 on success
2215  **/
2216 
2217 static int __init ip6_tunnel_init(void)
2218 {
2219 	int  err;
2220 
2221 	err = register_pernet_device(&ip6_tnl_net_ops);
2222 	if (err < 0)
2223 		goto out_pernet;
2224 
2225 	err = xfrm6_tunnel_register(&ip4ip6_handler, AF_INET);
2226 	if (err < 0) {
2227 		pr_err("%s: can't register ip4ip6\n", __func__);
2228 		goto out_ip4ip6;
2229 	}
2230 
2231 	err = xfrm6_tunnel_register(&ip6ip6_handler, AF_INET6);
2232 	if (err < 0) {
2233 		pr_err("%s: can't register ip6ip6\n", __func__);
2234 		goto out_ip6ip6;
2235 	}
2236 	err = rtnl_link_register(&ip6_link_ops);
2237 	if (err < 0)
2238 		goto rtnl_link_failed;
2239 
2240 	return 0;
2241 
2242 rtnl_link_failed:
2243 	xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6);
2244 out_ip6ip6:
2245 	xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET);
2246 out_ip4ip6:
2247 	unregister_pernet_device(&ip6_tnl_net_ops);
2248 out_pernet:
2249 	return err;
2250 }
2251 
2252 /**
2253  * ip6_tunnel_cleanup - free resources and unregister protocol
2254  **/
2255 
2256 static void __exit ip6_tunnel_cleanup(void)
2257 {
2258 	rtnl_link_unregister(&ip6_link_ops);
2259 	if (xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET))
2260 		pr_info("%s: can't deregister ip4ip6\n", __func__);
2261 
2262 	if (xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6))
2263 		pr_info("%s: can't deregister ip6ip6\n", __func__);
2264 
2265 	unregister_pernet_device(&ip6_tnl_net_ops);
2266 }
2267 
2268 module_init(ip6_tunnel_init);
2269 module_exit(ip6_tunnel_cleanup);
2270