xref: /linux/net/ipv6/ip6_gre.c (revision 02000b55850deeadffe433e4b4930a8831f477de)
1 /*
2  *	GRE over IPv6 protocol decoder.
3  *
4  *	Authors: Dmitry Kozlov (xeb@mail.ru)
5  *
6  *	This program is free software; you can redistribute it and/or
7  *	modify it under the terms of the GNU General Public License
8  *	as published by the Free Software Foundation; either version
9  *	2 of the License, or (at your option) any later version.
10  *
11  */
12 
13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14 
15 #include <linux/capability.h>
16 #include <linux/module.h>
17 #include <linux/types.h>
18 #include <linux/kernel.h>
19 #include <linux/slab.h>
20 #include <linux/uaccess.h>
21 #include <linux/skbuff.h>
22 #include <linux/netdevice.h>
23 #include <linux/in.h>
24 #include <linux/tcp.h>
25 #include <linux/udp.h>
26 #include <linux/if_arp.h>
27 #include <linux/init.h>
28 #include <linux/in6.h>
29 #include <linux/inetdevice.h>
30 #include <linux/igmp.h>
31 #include <linux/netfilter_ipv4.h>
32 #include <linux/etherdevice.h>
33 #include <linux/if_ether.h>
34 #include <linux/hash.h>
35 #include <linux/if_tunnel.h>
36 #include <linux/ip6_tunnel.h>
37 
38 #include <net/sock.h>
39 #include <net/ip.h>
40 #include <net/ip_tunnels.h>
41 #include <net/icmp.h>
42 #include <net/protocol.h>
43 #include <net/addrconf.h>
44 #include <net/arp.h>
45 #include <net/checksum.h>
46 #include <net/dsfield.h>
47 #include <net/inet_ecn.h>
48 #include <net/xfrm.h>
49 #include <net/net_namespace.h>
50 #include <net/netns/generic.h>
51 #include <net/rtnetlink.h>
52 
53 #include <net/ipv6.h>
54 #include <net/ip6_fib.h>
55 #include <net/ip6_route.h>
56 #include <net/ip6_tunnel.h>
57 #include <net/gre.h>
58 #include <net/erspan.h>
59 #include <net/dst_metadata.h>
60 
61 
62 static bool log_ecn_error = true;
63 module_param(log_ecn_error, bool, 0644);
64 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
65 
66 #define IP6_GRE_HASH_SIZE_SHIFT  5
67 #define IP6_GRE_HASH_SIZE (1 << IP6_GRE_HASH_SIZE_SHIFT)
68 
69 static unsigned int ip6gre_net_id __read_mostly;
70 struct ip6gre_net {
71 	struct ip6_tnl __rcu *tunnels[4][IP6_GRE_HASH_SIZE];
72 
73 	struct ip6_tnl __rcu *collect_md_tun;
74 	struct ip6_tnl __rcu *collect_md_tun_erspan;
75 	struct net_device *fb_tunnel_dev;
76 };
77 
78 static struct rtnl_link_ops ip6gre_link_ops __read_mostly;
79 static struct rtnl_link_ops ip6gre_tap_ops __read_mostly;
80 static struct rtnl_link_ops ip6erspan_tap_ops __read_mostly;
81 static int ip6gre_tunnel_init(struct net_device *dev);
82 static void ip6gre_tunnel_setup(struct net_device *dev);
83 static void ip6gre_tunnel_link(struct ip6gre_net *ign, struct ip6_tnl *t);
84 static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu);
85 static void ip6erspan_tnl_link_config(struct ip6_tnl *t, int set_mtu);
86 
87 /* Tunnel hash table */
88 
89 /*
90    4 hash tables:
91 
92    3: (remote,local)
93    2: (remote,*)
94    1: (*,local)
95    0: (*,*)
96 
97    We require exact key match i.e. if a key is present in packet
98    it will match only tunnel with the same key; if it is not present,
99    it will match only keyless tunnel.
100 
101    All keysless packets, if not matched configured keyless tunnels
102    will match fallback tunnel.
103  */
104 
105 #define HASH_KEY(key) (((__force u32)key^((__force u32)key>>4))&(IP6_GRE_HASH_SIZE - 1))
106 static u32 HASH_ADDR(const struct in6_addr *addr)
107 {
108 	u32 hash = ipv6_addr_hash(addr);
109 
110 	return hash_32(hash, IP6_GRE_HASH_SIZE_SHIFT);
111 }
112 
113 #define tunnels_r_l	tunnels[3]
114 #define tunnels_r	tunnels[2]
115 #define tunnels_l	tunnels[1]
116 #define tunnels_wc	tunnels[0]
117 
118 /* Given src, dst and key, find appropriate for input tunnel. */
119 
120 static struct ip6_tnl *ip6gre_tunnel_lookup(struct net_device *dev,
121 		const struct in6_addr *remote, const struct in6_addr *local,
122 		__be32 key, __be16 gre_proto)
123 {
124 	struct net *net = dev_net(dev);
125 	int link = dev->ifindex;
126 	unsigned int h0 = HASH_ADDR(remote);
127 	unsigned int h1 = HASH_KEY(key);
128 	struct ip6_tnl *t, *cand = NULL;
129 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
130 	int dev_type = (gre_proto == htons(ETH_P_TEB) ||
131 			gre_proto == htons(ETH_P_ERSPAN) ||
132 			gre_proto == htons(ETH_P_ERSPAN2)) ?
133 		       ARPHRD_ETHER : ARPHRD_IP6GRE;
134 	int score, cand_score = 4;
135 
136 	for_each_ip_tunnel_rcu(t, ign->tunnels_r_l[h0 ^ h1]) {
137 		if (!ipv6_addr_equal(local, &t->parms.laddr) ||
138 		    !ipv6_addr_equal(remote, &t->parms.raddr) ||
139 		    key != t->parms.i_key ||
140 		    !(t->dev->flags & IFF_UP))
141 			continue;
142 
143 		if (t->dev->type != ARPHRD_IP6GRE &&
144 		    t->dev->type != dev_type)
145 			continue;
146 
147 		score = 0;
148 		if (t->parms.link != link)
149 			score |= 1;
150 		if (t->dev->type != dev_type)
151 			score |= 2;
152 		if (score == 0)
153 			return t;
154 
155 		if (score < cand_score) {
156 			cand = t;
157 			cand_score = score;
158 		}
159 	}
160 
161 	for_each_ip_tunnel_rcu(t, ign->tunnels_r[h0 ^ h1]) {
162 		if (!ipv6_addr_equal(remote, &t->parms.raddr) ||
163 		    key != t->parms.i_key ||
164 		    !(t->dev->flags & IFF_UP))
165 			continue;
166 
167 		if (t->dev->type != ARPHRD_IP6GRE &&
168 		    t->dev->type != dev_type)
169 			continue;
170 
171 		score = 0;
172 		if (t->parms.link != link)
173 			score |= 1;
174 		if (t->dev->type != dev_type)
175 			score |= 2;
176 		if (score == 0)
177 			return t;
178 
179 		if (score < cand_score) {
180 			cand = t;
181 			cand_score = score;
182 		}
183 	}
184 
185 	for_each_ip_tunnel_rcu(t, ign->tunnels_l[h1]) {
186 		if ((!ipv6_addr_equal(local, &t->parms.laddr) &&
187 			  (!ipv6_addr_equal(local, &t->parms.raddr) ||
188 				 !ipv6_addr_is_multicast(local))) ||
189 		    key != t->parms.i_key ||
190 		    !(t->dev->flags & IFF_UP))
191 			continue;
192 
193 		if (t->dev->type != ARPHRD_IP6GRE &&
194 		    t->dev->type != dev_type)
195 			continue;
196 
197 		score = 0;
198 		if (t->parms.link != link)
199 			score |= 1;
200 		if (t->dev->type != dev_type)
201 			score |= 2;
202 		if (score == 0)
203 			return t;
204 
205 		if (score < cand_score) {
206 			cand = t;
207 			cand_score = score;
208 		}
209 	}
210 
211 	for_each_ip_tunnel_rcu(t, ign->tunnels_wc[h1]) {
212 		if (t->parms.i_key != key ||
213 		    !(t->dev->flags & IFF_UP))
214 			continue;
215 
216 		if (t->dev->type != ARPHRD_IP6GRE &&
217 		    t->dev->type != dev_type)
218 			continue;
219 
220 		score = 0;
221 		if (t->parms.link != link)
222 			score |= 1;
223 		if (t->dev->type != dev_type)
224 			score |= 2;
225 		if (score == 0)
226 			return t;
227 
228 		if (score < cand_score) {
229 			cand = t;
230 			cand_score = score;
231 		}
232 	}
233 
234 	if (cand)
235 		return cand;
236 
237 	if (gre_proto == htons(ETH_P_ERSPAN) ||
238 	    gre_proto == htons(ETH_P_ERSPAN2))
239 		t = rcu_dereference(ign->collect_md_tun_erspan);
240 	else
241 		t = rcu_dereference(ign->collect_md_tun);
242 
243 	if (t && t->dev->flags & IFF_UP)
244 		return t;
245 
246 	dev = ign->fb_tunnel_dev;
247 	if (dev && dev->flags & IFF_UP)
248 		return netdev_priv(dev);
249 
250 	return NULL;
251 }
252 
253 static struct ip6_tnl __rcu **__ip6gre_bucket(struct ip6gre_net *ign,
254 		const struct __ip6_tnl_parm *p)
255 {
256 	const struct in6_addr *remote = &p->raddr;
257 	const struct in6_addr *local = &p->laddr;
258 	unsigned int h = HASH_KEY(p->i_key);
259 	int prio = 0;
260 
261 	if (!ipv6_addr_any(local))
262 		prio |= 1;
263 	if (!ipv6_addr_any(remote) && !ipv6_addr_is_multicast(remote)) {
264 		prio |= 2;
265 		h ^= HASH_ADDR(remote);
266 	}
267 
268 	return &ign->tunnels[prio][h];
269 }
270 
271 static void ip6gre_tunnel_link_md(struct ip6gre_net *ign, struct ip6_tnl *t)
272 {
273 	if (t->parms.collect_md)
274 		rcu_assign_pointer(ign->collect_md_tun, t);
275 }
276 
277 static void ip6erspan_tunnel_link_md(struct ip6gre_net *ign, struct ip6_tnl *t)
278 {
279 	if (t->parms.collect_md)
280 		rcu_assign_pointer(ign->collect_md_tun_erspan, t);
281 }
282 
283 static void ip6gre_tunnel_unlink_md(struct ip6gre_net *ign, struct ip6_tnl *t)
284 {
285 	if (t->parms.collect_md)
286 		rcu_assign_pointer(ign->collect_md_tun, NULL);
287 }
288 
289 static void ip6erspan_tunnel_unlink_md(struct ip6gre_net *ign,
290 				       struct ip6_tnl *t)
291 {
292 	if (t->parms.collect_md)
293 		rcu_assign_pointer(ign->collect_md_tun_erspan, NULL);
294 }
295 
296 static inline struct ip6_tnl __rcu **ip6gre_bucket(struct ip6gre_net *ign,
297 		const struct ip6_tnl *t)
298 {
299 	return __ip6gre_bucket(ign, &t->parms);
300 }
301 
302 static void ip6gre_tunnel_link(struct ip6gre_net *ign, struct ip6_tnl *t)
303 {
304 	struct ip6_tnl __rcu **tp = ip6gre_bucket(ign, t);
305 
306 	rcu_assign_pointer(t->next, rtnl_dereference(*tp));
307 	rcu_assign_pointer(*tp, t);
308 }
309 
310 static void ip6gre_tunnel_unlink(struct ip6gre_net *ign, struct ip6_tnl *t)
311 {
312 	struct ip6_tnl __rcu **tp;
313 	struct ip6_tnl *iter;
314 
315 	for (tp = ip6gre_bucket(ign, t);
316 	     (iter = rtnl_dereference(*tp)) != NULL;
317 	     tp = &iter->next) {
318 		if (t == iter) {
319 			rcu_assign_pointer(*tp, t->next);
320 			break;
321 		}
322 	}
323 }
324 
325 static struct ip6_tnl *ip6gre_tunnel_find(struct net *net,
326 					   const struct __ip6_tnl_parm *parms,
327 					   int type)
328 {
329 	const struct in6_addr *remote = &parms->raddr;
330 	const struct in6_addr *local = &parms->laddr;
331 	__be32 key = parms->i_key;
332 	int link = parms->link;
333 	struct ip6_tnl *t;
334 	struct ip6_tnl __rcu **tp;
335 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
336 
337 	for (tp = __ip6gre_bucket(ign, parms);
338 	     (t = rtnl_dereference(*tp)) != NULL;
339 	     tp = &t->next)
340 		if (ipv6_addr_equal(local, &t->parms.laddr) &&
341 		    ipv6_addr_equal(remote, &t->parms.raddr) &&
342 		    key == t->parms.i_key &&
343 		    link == t->parms.link &&
344 		    type == t->dev->type)
345 			break;
346 
347 	return t;
348 }
349 
350 static struct ip6_tnl *ip6gre_tunnel_locate(struct net *net,
351 		const struct __ip6_tnl_parm *parms, int create)
352 {
353 	struct ip6_tnl *t, *nt;
354 	struct net_device *dev;
355 	char name[IFNAMSIZ];
356 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
357 
358 	t = ip6gre_tunnel_find(net, parms, ARPHRD_IP6GRE);
359 	if (t && create)
360 		return NULL;
361 	if (t || !create)
362 		return t;
363 
364 	if (parms->name[0]) {
365 		if (!dev_valid_name(parms->name))
366 			return NULL;
367 		strlcpy(name, parms->name, IFNAMSIZ);
368 	} else {
369 		strcpy(name, "ip6gre%d");
370 	}
371 	dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
372 			   ip6gre_tunnel_setup);
373 	if (!dev)
374 		return NULL;
375 
376 	dev_net_set(dev, net);
377 
378 	nt = netdev_priv(dev);
379 	nt->parms = *parms;
380 	dev->rtnl_link_ops = &ip6gre_link_ops;
381 
382 	nt->dev = dev;
383 	nt->net = dev_net(dev);
384 
385 	if (register_netdevice(dev) < 0)
386 		goto failed_free;
387 
388 	ip6gre_tnl_link_config(nt, 1);
389 
390 	/* Can use a lockless transmit, unless we generate output sequences */
391 	if (!(nt->parms.o_flags & TUNNEL_SEQ))
392 		dev->features |= NETIF_F_LLTX;
393 
394 	dev_hold(dev);
395 	ip6gre_tunnel_link(ign, nt);
396 	return nt;
397 
398 failed_free:
399 	free_netdev(dev);
400 	return NULL;
401 }
402 
403 static void ip6erspan_tunnel_uninit(struct net_device *dev)
404 {
405 	struct ip6_tnl *t = netdev_priv(dev);
406 	struct ip6gre_net *ign = net_generic(t->net, ip6gre_net_id);
407 
408 	ip6erspan_tunnel_unlink_md(ign, t);
409 	ip6gre_tunnel_unlink(ign, t);
410 	dst_cache_reset(&t->dst_cache);
411 	dev_put(dev);
412 }
413 
414 static void ip6gre_tunnel_uninit(struct net_device *dev)
415 {
416 	struct ip6_tnl *t = netdev_priv(dev);
417 	struct ip6gre_net *ign = net_generic(t->net, ip6gre_net_id);
418 
419 	ip6gre_tunnel_unlink_md(ign, t);
420 	ip6gre_tunnel_unlink(ign, t);
421 	dst_cache_reset(&t->dst_cache);
422 	dev_put(dev);
423 }
424 
425 
426 static void ip6gre_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
427 		       u8 type, u8 code, int offset, __be32 info)
428 {
429 	struct net *net = dev_net(skb->dev);
430 	const struct gre_base_hdr *greh;
431 	const struct ipv6hdr *ipv6h;
432 	int grehlen = sizeof(*greh);
433 	struct ip6_tnl *t;
434 	int key_off = 0;
435 	__be16 flags;
436 	__be32 key;
437 
438 	if (!pskb_may_pull(skb, offset + grehlen))
439 		return;
440 	greh = (const struct gre_base_hdr *)(skb->data + offset);
441 	flags = greh->flags;
442 	if (flags & (GRE_VERSION | GRE_ROUTING))
443 		return;
444 	if (flags & GRE_CSUM)
445 		grehlen += 4;
446 	if (flags & GRE_KEY) {
447 		key_off = grehlen + offset;
448 		grehlen += 4;
449 	}
450 
451 	if (!pskb_may_pull(skb, offset + grehlen))
452 		return;
453 	ipv6h = (const struct ipv6hdr *)skb->data;
454 	greh = (const struct gre_base_hdr *)(skb->data + offset);
455 	key = key_off ? *(__be32 *)(skb->data + key_off) : 0;
456 
457 	t = ip6gre_tunnel_lookup(skb->dev, &ipv6h->daddr, &ipv6h->saddr,
458 				 key, greh->protocol);
459 	if (!t)
460 		return;
461 
462 	switch (type) {
463 		struct ipv6_tlv_tnl_enc_lim *tel;
464 		__u32 teli;
465 	case ICMPV6_DEST_UNREACH:
466 		net_dbg_ratelimited("%s: Path to destination invalid or inactive!\n",
467 				    t->parms.name);
468 		if (code != ICMPV6_PORT_UNREACH)
469 			break;
470 		return;
471 	case ICMPV6_TIME_EXCEED:
472 		if (code == ICMPV6_EXC_HOPLIMIT) {
473 			net_dbg_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
474 					    t->parms.name);
475 			break;
476 		}
477 		return;
478 	case ICMPV6_PARAMPROB:
479 		teli = 0;
480 		if (code == ICMPV6_HDR_FIELD)
481 			teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
482 
483 		if (teli && teli == be32_to_cpu(info) - 2) {
484 			tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
485 			if (tel->encap_limit == 0) {
486 				net_dbg_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
487 						    t->parms.name);
488 			}
489 		} else {
490 			net_dbg_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
491 					    t->parms.name);
492 		}
493 		return;
494 	case ICMPV6_PKT_TOOBIG:
495 		ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL));
496 		return;
497 	case NDISC_REDIRECT:
498 		ip6_redirect(skb, net, skb->dev->ifindex, 0,
499 			     sock_net_uid(net, NULL));
500 		return;
501 	}
502 
503 	if (time_before(jiffies, t->err_time + IP6TUNNEL_ERR_TIMEO))
504 		t->err_count++;
505 	else
506 		t->err_count = 1;
507 	t->err_time = jiffies;
508 }
509 
510 static int ip6gre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi)
511 {
512 	const struct ipv6hdr *ipv6h;
513 	struct ip6_tnl *tunnel;
514 
515 	ipv6h = ipv6_hdr(skb);
516 	tunnel = ip6gre_tunnel_lookup(skb->dev,
517 				      &ipv6h->saddr, &ipv6h->daddr, tpi->key,
518 				      tpi->proto);
519 	if (tunnel) {
520 		if (tunnel->parms.collect_md) {
521 			struct metadata_dst *tun_dst;
522 			__be64 tun_id;
523 			__be16 flags;
524 
525 			flags = tpi->flags;
526 			tun_id = key32_to_tunnel_id(tpi->key);
527 
528 			tun_dst = ipv6_tun_rx_dst(skb, flags, tun_id, 0);
529 			if (!tun_dst)
530 				return PACKET_REJECT;
531 
532 			ip6_tnl_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error);
533 		} else {
534 			ip6_tnl_rcv(tunnel, skb, tpi, NULL, log_ecn_error);
535 		}
536 
537 		return PACKET_RCVD;
538 	}
539 
540 	return PACKET_REJECT;
541 }
542 
543 static int ip6erspan_rcv(struct sk_buff *skb, int gre_hdr_len,
544 			 struct tnl_ptk_info *tpi)
545 {
546 	struct erspan_base_hdr *ershdr;
547 	struct erspan_metadata *pkt_md;
548 	const struct ipv6hdr *ipv6h;
549 	struct erspan_md2 *md2;
550 	struct ip6_tnl *tunnel;
551 	u8 ver;
552 
553 	if (unlikely(!pskb_may_pull(skb, sizeof(*ershdr))))
554 		return PACKET_REJECT;
555 
556 	ipv6h = ipv6_hdr(skb);
557 	ershdr = (struct erspan_base_hdr *)skb->data;
558 	ver = ershdr->ver;
559 	tpi->key = cpu_to_be32(get_session_id(ershdr));
560 
561 	tunnel = ip6gre_tunnel_lookup(skb->dev,
562 				      &ipv6h->saddr, &ipv6h->daddr, tpi->key,
563 				      tpi->proto);
564 	if (tunnel) {
565 		int len = erspan_hdr_len(ver);
566 
567 		if (unlikely(!pskb_may_pull(skb, len)))
568 			return PACKET_REJECT;
569 
570 		ershdr = (struct erspan_base_hdr *)skb->data;
571 		pkt_md = (struct erspan_metadata *)(ershdr + 1);
572 
573 		if (__iptunnel_pull_header(skb, len,
574 					   htons(ETH_P_TEB),
575 					   false, false) < 0)
576 			return PACKET_REJECT;
577 
578 		if (tunnel->parms.collect_md) {
579 			struct metadata_dst *tun_dst;
580 			struct ip_tunnel_info *info;
581 			struct erspan_metadata *md;
582 			__be64 tun_id;
583 			__be16 flags;
584 
585 			tpi->flags |= TUNNEL_KEY;
586 			flags = tpi->flags;
587 			tun_id = key32_to_tunnel_id(tpi->key);
588 
589 			tun_dst = ipv6_tun_rx_dst(skb, flags, tun_id,
590 						  sizeof(*md));
591 			if (!tun_dst)
592 				return PACKET_REJECT;
593 
594 			info = &tun_dst->u.tun_info;
595 			md = ip_tunnel_info_opts(info);
596 			md->version = ver;
597 			md2 = &md->u.md2;
598 			memcpy(md2, pkt_md, ver == 1 ? ERSPAN_V1_MDSIZE :
599 						       ERSPAN_V2_MDSIZE);
600 			info->key.tun_flags |= TUNNEL_ERSPAN_OPT;
601 			info->options_len = sizeof(*md);
602 
603 			ip6_tnl_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error);
604 
605 		} else {
606 			ip6_tnl_rcv(tunnel, skb, tpi, NULL, log_ecn_error);
607 		}
608 
609 		return PACKET_RCVD;
610 	}
611 
612 	return PACKET_REJECT;
613 }
614 
615 static int gre_rcv(struct sk_buff *skb)
616 {
617 	struct tnl_ptk_info tpi;
618 	bool csum_err = false;
619 	int hdr_len;
620 
621 	hdr_len = gre_parse_header(skb, &tpi, &csum_err, htons(ETH_P_IPV6), 0);
622 	if (hdr_len < 0)
623 		goto drop;
624 
625 	if (iptunnel_pull_header(skb, hdr_len, tpi.proto, false))
626 		goto drop;
627 
628 	if (unlikely(tpi.proto == htons(ETH_P_ERSPAN) ||
629 		     tpi.proto == htons(ETH_P_ERSPAN2))) {
630 		if (ip6erspan_rcv(skb, hdr_len, &tpi) == PACKET_RCVD)
631 			return 0;
632 		goto out;
633 	}
634 
635 	if (ip6gre_rcv(skb, &tpi) == PACKET_RCVD)
636 		return 0;
637 
638 out:
639 	icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
640 drop:
641 	kfree_skb(skb);
642 	return 0;
643 }
644 
645 static int gre_handle_offloads(struct sk_buff *skb, bool csum)
646 {
647 	return iptunnel_handle_offloads(skb,
648 					csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE);
649 }
650 
651 static void prepare_ip6gre_xmit_ipv4(struct sk_buff *skb,
652 				     struct net_device *dev,
653 				     struct flowi6 *fl6, __u8 *dsfield,
654 				     int *encap_limit)
655 {
656 	const struct iphdr *iph = ip_hdr(skb);
657 	struct ip6_tnl *t = netdev_priv(dev);
658 
659 	if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
660 		*encap_limit = t->parms.encap_limit;
661 
662 	memcpy(fl6, &t->fl.u.ip6, sizeof(*fl6));
663 
664 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
665 		*dsfield = ipv4_get_dsfield(iph);
666 	else
667 		*dsfield = ip6_tclass(t->parms.flowinfo);
668 
669 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
670 		fl6->flowi6_mark = skb->mark;
671 	else
672 		fl6->flowi6_mark = t->parms.fwmark;
673 
674 	fl6->flowi6_uid = sock_net_uid(dev_net(dev), NULL);
675 }
676 
677 static int prepare_ip6gre_xmit_ipv6(struct sk_buff *skb,
678 				    struct net_device *dev,
679 				    struct flowi6 *fl6, __u8 *dsfield,
680 				    int *encap_limit)
681 {
682 	struct ipv6hdr *ipv6h = ipv6_hdr(skb);
683 	struct ip6_tnl *t = netdev_priv(dev);
684 	__u16 offset;
685 
686 	offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
687 	/* ip6_tnl_parse_tlv_enc_lim() might have reallocated skb->head */
688 
689 	if (offset > 0) {
690 		struct ipv6_tlv_tnl_enc_lim *tel;
691 
692 		tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset];
693 		if (tel->encap_limit == 0) {
694 			icmpv6_send(skb, ICMPV6_PARAMPROB,
695 				    ICMPV6_HDR_FIELD, offset + 2);
696 			return -1;
697 		}
698 		*encap_limit = tel->encap_limit - 1;
699 	} else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) {
700 		*encap_limit = t->parms.encap_limit;
701 	}
702 
703 	memcpy(fl6, &t->fl.u.ip6, sizeof(*fl6));
704 
705 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
706 		*dsfield = ipv6_get_dsfield(ipv6h);
707 	else
708 		*dsfield = ip6_tclass(t->parms.flowinfo);
709 
710 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
711 		fl6->flowlabel |= ip6_flowlabel(ipv6h);
712 
713 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
714 		fl6->flowi6_mark = skb->mark;
715 	else
716 		fl6->flowi6_mark = t->parms.fwmark;
717 
718 	fl6->flowi6_uid = sock_net_uid(dev_net(dev), NULL);
719 
720 	return 0;
721 }
722 
723 static netdev_tx_t __gre6_xmit(struct sk_buff *skb,
724 			       struct net_device *dev, __u8 dsfield,
725 			       struct flowi6 *fl6, int encap_limit,
726 			       __u32 *pmtu, __be16 proto)
727 {
728 	struct ip6_tnl *tunnel = netdev_priv(dev);
729 	__be16 protocol;
730 
731 	if (dev->type == ARPHRD_ETHER)
732 		IPCB(skb)->flags = 0;
733 
734 	if (dev->header_ops && dev->type == ARPHRD_IP6GRE)
735 		fl6->daddr = ((struct ipv6hdr *)skb->data)->daddr;
736 	else
737 		fl6->daddr = tunnel->parms.raddr;
738 
739 	if (skb_cow_head(skb, dev->needed_headroom ?: tunnel->hlen))
740 		return -ENOMEM;
741 
742 	/* Push GRE header. */
743 	protocol = (dev->type == ARPHRD_ETHER) ? htons(ETH_P_TEB) : proto;
744 
745 	if (tunnel->parms.collect_md) {
746 		struct ip_tunnel_info *tun_info;
747 		const struct ip_tunnel_key *key;
748 		__be16 flags;
749 
750 		tun_info = skb_tunnel_info(skb);
751 		if (unlikely(!tun_info ||
752 			     !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
753 			     ip_tunnel_info_af(tun_info) != AF_INET6))
754 			return -EINVAL;
755 
756 		key = &tun_info->key;
757 		memset(fl6, 0, sizeof(*fl6));
758 		fl6->flowi6_proto = IPPROTO_GRE;
759 		fl6->daddr = key->u.ipv6.dst;
760 		fl6->flowlabel = key->label;
761 		fl6->flowi6_uid = sock_net_uid(dev_net(dev), NULL);
762 
763 		dsfield = key->tos;
764 		flags = key->tun_flags &
765 			(TUNNEL_CSUM | TUNNEL_KEY | TUNNEL_SEQ);
766 		tunnel->tun_hlen = gre_calc_hlen(flags);
767 
768 		gre_build_header(skb, tunnel->tun_hlen,
769 				 flags, protocol,
770 				 tunnel_id_to_key32(tun_info->key.tun_id),
771 				 (flags & TUNNEL_SEQ) ? htonl(tunnel->o_seqno++)
772 						      : 0);
773 
774 	} else {
775 		if (tunnel->parms.o_flags & TUNNEL_SEQ)
776 			tunnel->o_seqno++;
777 
778 		gre_build_header(skb, tunnel->tun_hlen, tunnel->parms.o_flags,
779 				 protocol, tunnel->parms.o_key,
780 				 htonl(tunnel->o_seqno));
781 	}
782 
783 	return ip6_tnl_xmit(skb, dev, dsfield, fl6, encap_limit, pmtu,
784 			    NEXTHDR_GRE);
785 }
786 
787 static inline int ip6gre_xmit_ipv4(struct sk_buff *skb, struct net_device *dev)
788 {
789 	struct ip6_tnl *t = netdev_priv(dev);
790 	int encap_limit = -1;
791 	struct flowi6 fl6;
792 	__u8 dsfield = 0;
793 	__u32 mtu;
794 	int err;
795 
796 	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
797 
798 	if (!t->parms.collect_md)
799 		prepare_ip6gre_xmit_ipv4(skb, dev, &fl6,
800 					 &dsfield, &encap_limit);
801 
802 	err = gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM));
803 	if (err)
804 		return -1;
805 
806 	err = __gre6_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
807 			  skb->protocol);
808 	if (err != 0) {
809 		/* XXX: send ICMP error even if DF is not set. */
810 		if (err == -EMSGSIZE)
811 			icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
812 				  htonl(mtu));
813 		return -1;
814 	}
815 
816 	return 0;
817 }
818 
819 static inline int ip6gre_xmit_ipv6(struct sk_buff *skb, struct net_device *dev)
820 {
821 	struct ip6_tnl *t = netdev_priv(dev);
822 	struct ipv6hdr *ipv6h = ipv6_hdr(skb);
823 	int encap_limit = -1;
824 	struct flowi6 fl6;
825 	__u8 dsfield = 0;
826 	__u32 mtu;
827 	int err;
828 
829 	if (ipv6_addr_equal(&t->parms.raddr, &ipv6h->saddr))
830 		return -1;
831 
832 	if (!t->parms.collect_md &&
833 	    prepare_ip6gre_xmit_ipv6(skb, dev, &fl6, &dsfield, &encap_limit))
834 		return -1;
835 
836 	if (gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM)))
837 		return -1;
838 
839 	err = __gre6_xmit(skb, dev, dsfield, &fl6, encap_limit,
840 			  &mtu, skb->protocol);
841 	if (err != 0) {
842 		if (err == -EMSGSIZE)
843 			icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
844 		return -1;
845 	}
846 
847 	return 0;
848 }
849 
850 /**
851  * ip6gre_tnl_addr_conflict - compare packet addresses to tunnel's own
852  *   @t: the outgoing tunnel device
853  *   @hdr: IPv6 header from the incoming packet
854  *
855  * Description:
856  *   Avoid trivial tunneling loop by checking that tunnel exit-point
857  *   doesn't match source of incoming packet.
858  *
859  * Return:
860  *   1 if conflict,
861  *   0 else
862  **/
863 
864 static inline bool ip6gre_tnl_addr_conflict(const struct ip6_tnl *t,
865 	const struct ipv6hdr *hdr)
866 {
867 	return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
868 }
869 
870 static int ip6gre_xmit_other(struct sk_buff *skb, struct net_device *dev)
871 {
872 	struct ip6_tnl *t = netdev_priv(dev);
873 	int encap_limit = -1;
874 	struct flowi6 fl6;
875 	__u32 mtu;
876 	int err;
877 
878 	if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
879 		encap_limit = t->parms.encap_limit;
880 
881 	if (!t->parms.collect_md)
882 		memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
883 
884 	err = gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM));
885 	if (err)
886 		return err;
887 
888 	err = __gre6_xmit(skb, dev, 0, &fl6, encap_limit, &mtu, skb->protocol);
889 
890 	return err;
891 }
892 
893 static netdev_tx_t ip6gre_tunnel_xmit(struct sk_buff *skb,
894 	struct net_device *dev)
895 {
896 	struct ip6_tnl *t = netdev_priv(dev);
897 	struct net_device_stats *stats = &t->dev->stats;
898 	int ret;
899 
900 	if (!ip6_tnl_xmit_ctl(t, &t->parms.laddr, &t->parms.raddr))
901 		goto tx_err;
902 
903 	switch (skb->protocol) {
904 	case htons(ETH_P_IP):
905 		ret = ip6gre_xmit_ipv4(skb, dev);
906 		break;
907 	case htons(ETH_P_IPV6):
908 		ret = ip6gre_xmit_ipv6(skb, dev);
909 		break;
910 	default:
911 		ret = ip6gre_xmit_other(skb, dev);
912 		break;
913 	}
914 
915 	if (ret < 0)
916 		goto tx_err;
917 
918 	return NETDEV_TX_OK;
919 
920 tx_err:
921 	stats->tx_errors++;
922 	stats->tx_dropped++;
923 	kfree_skb(skb);
924 	return NETDEV_TX_OK;
925 }
926 
927 static netdev_tx_t ip6erspan_tunnel_xmit(struct sk_buff *skb,
928 					 struct net_device *dev)
929 {
930 	struct ipv6hdr *ipv6h = ipv6_hdr(skb);
931 	struct ip6_tnl *t = netdev_priv(dev);
932 	struct dst_entry *dst = skb_dst(skb);
933 	struct net_device_stats *stats;
934 	bool truncate = false;
935 	int encap_limit = -1;
936 	__u8 dsfield = false;
937 	struct flowi6 fl6;
938 	int err = -EINVAL;
939 	__u32 mtu;
940 	int nhoff;
941 	int thoff;
942 
943 	if (!ip6_tnl_xmit_ctl(t, &t->parms.laddr, &t->parms.raddr))
944 		goto tx_err;
945 
946 	if (gre_handle_offloads(skb, false))
947 		goto tx_err;
948 
949 	if (skb->len > dev->mtu + dev->hard_header_len) {
950 		pskb_trim(skb, dev->mtu + dev->hard_header_len);
951 		truncate = true;
952 	}
953 
954 	nhoff = skb_network_header(skb) - skb_mac_header(skb);
955 	if (skb->protocol == htons(ETH_P_IP) &&
956 	    (ntohs(ip_hdr(skb)->tot_len) > skb->len - nhoff))
957 		truncate = true;
958 
959 	thoff = skb_transport_header(skb) - skb_mac_header(skb);
960 	if (skb->protocol == htons(ETH_P_IPV6) &&
961 	    (ntohs(ipv6_hdr(skb)->payload_len) > skb->len - thoff))
962 		truncate = true;
963 
964 	if (skb_cow_head(skb, dev->needed_headroom ?: t->hlen))
965 		goto tx_err;
966 
967 	t->parms.o_flags &= ~TUNNEL_KEY;
968 	IPCB(skb)->flags = 0;
969 
970 	/* For collect_md mode, derive fl6 from the tunnel key,
971 	 * for native mode, call prepare_ip6gre_xmit_{ipv4,ipv6}.
972 	 */
973 	if (t->parms.collect_md) {
974 		struct ip_tunnel_info *tun_info;
975 		const struct ip_tunnel_key *key;
976 		struct erspan_metadata *md;
977 		__be32 tun_id;
978 
979 		tun_info = skb_tunnel_info(skb);
980 		if (unlikely(!tun_info ||
981 			     !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
982 			     ip_tunnel_info_af(tun_info) != AF_INET6))
983 			return -EINVAL;
984 
985 		key = &tun_info->key;
986 		memset(&fl6, 0, sizeof(fl6));
987 		fl6.flowi6_proto = IPPROTO_GRE;
988 		fl6.daddr = key->u.ipv6.dst;
989 		fl6.flowlabel = key->label;
990 		fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
991 
992 		dsfield = key->tos;
993 		if (!(tun_info->key.tun_flags & TUNNEL_ERSPAN_OPT))
994 			goto tx_err;
995 		md = ip_tunnel_info_opts(tun_info);
996 		if (!md)
997 			goto tx_err;
998 
999 		tun_id = tunnel_id_to_key32(key->tun_id);
1000 		if (md->version == 1) {
1001 			erspan_build_header(skb,
1002 					    ntohl(tun_id),
1003 					    ntohl(md->u.index), truncate,
1004 					    false);
1005 		} else if (md->version == 2) {
1006 			erspan_build_header_v2(skb,
1007 					       ntohl(tun_id),
1008 					       md->u.md2.dir,
1009 					       get_hwid(&md->u.md2),
1010 					       truncate, false);
1011 		} else {
1012 			goto tx_err;
1013 		}
1014 	} else {
1015 		switch (skb->protocol) {
1016 		case htons(ETH_P_IP):
1017 			memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1018 			prepare_ip6gre_xmit_ipv4(skb, dev, &fl6,
1019 						 &dsfield, &encap_limit);
1020 			break;
1021 		case htons(ETH_P_IPV6):
1022 			if (ipv6_addr_equal(&t->parms.raddr, &ipv6h->saddr))
1023 				goto tx_err;
1024 			if (prepare_ip6gre_xmit_ipv6(skb, dev, &fl6,
1025 						     &dsfield, &encap_limit))
1026 				goto tx_err;
1027 			break;
1028 		default:
1029 			memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
1030 			break;
1031 		}
1032 
1033 		if (t->parms.erspan_ver == 1)
1034 			erspan_build_header(skb, ntohl(t->parms.o_key),
1035 					    t->parms.index,
1036 					    truncate, false);
1037 		else if (t->parms.erspan_ver == 2)
1038 			erspan_build_header_v2(skb, ntohl(t->parms.o_key),
1039 					       t->parms.dir,
1040 					       t->parms.hwid,
1041 					       truncate, false);
1042 		else
1043 			goto tx_err;
1044 
1045 		fl6.daddr = t->parms.raddr;
1046 	}
1047 
1048 	/* Push GRE header. */
1049 	gre_build_header(skb, 8, TUNNEL_SEQ,
1050 			 htons(ETH_P_ERSPAN), 0, htonl(t->o_seqno++));
1051 
1052 	/* TooBig packet may have updated dst->dev's mtu */
1053 	if (!t->parms.collect_md && dst && dst_mtu(dst) > dst->dev->mtu)
1054 		dst->ops->update_pmtu(dst, NULL, skb, dst->dev->mtu);
1055 
1056 	err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
1057 			   NEXTHDR_GRE);
1058 	if (err != 0) {
1059 		/* XXX: send ICMP error even if DF is not set. */
1060 		if (err == -EMSGSIZE) {
1061 			if (skb->protocol == htons(ETH_P_IP))
1062 				icmp_send(skb, ICMP_DEST_UNREACH,
1063 					  ICMP_FRAG_NEEDED, htonl(mtu));
1064 			else
1065 				icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
1066 		}
1067 
1068 		goto tx_err;
1069 	}
1070 	return NETDEV_TX_OK;
1071 
1072 tx_err:
1073 	stats = &t->dev->stats;
1074 	stats->tx_errors++;
1075 	stats->tx_dropped++;
1076 	kfree_skb(skb);
1077 	return NETDEV_TX_OK;
1078 }
1079 
1080 static void ip6gre_tnl_link_config_common(struct ip6_tnl *t)
1081 {
1082 	struct net_device *dev = t->dev;
1083 	struct __ip6_tnl_parm *p = &t->parms;
1084 	struct flowi6 *fl6 = &t->fl.u.ip6;
1085 
1086 	if (dev->type != ARPHRD_ETHER) {
1087 		memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
1088 		memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
1089 	}
1090 
1091 	/* Set up flowi template */
1092 	fl6->saddr = p->laddr;
1093 	fl6->daddr = p->raddr;
1094 	fl6->flowi6_oif = p->link;
1095 	fl6->flowlabel = 0;
1096 	fl6->flowi6_proto = IPPROTO_GRE;
1097 
1098 	if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
1099 		fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
1100 	if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
1101 		fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
1102 
1103 	p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
1104 	p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
1105 
1106 	if (p->flags&IP6_TNL_F_CAP_XMIT &&
1107 			p->flags&IP6_TNL_F_CAP_RCV && dev->type != ARPHRD_ETHER)
1108 		dev->flags |= IFF_POINTOPOINT;
1109 	else
1110 		dev->flags &= ~IFF_POINTOPOINT;
1111 }
1112 
1113 static void ip6gre_tnl_link_config_route(struct ip6_tnl *t, int set_mtu,
1114 					 int t_hlen)
1115 {
1116 	const struct __ip6_tnl_parm *p = &t->parms;
1117 	struct net_device *dev = t->dev;
1118 
1119 	if (p->flags & IP6_TNL_F_CAP_XMIT) {
1120 		int strict = (ipv6_addr_type(&p->raddr) &
1121 			      (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
1122 
1123 		struct rt6_info *rt = rt6_lookup(t->net,
1124 						 &p->raddr, &p->laddr,
1125 						 p->link, NULL, strict);
1126 
1127 		if (!rt)
1128 			return;
1129 
1130 		if (rt->dst.dev) {
1131 			dev->hard_header_len = rt->dst.dev->hard_header_len +
1132 					       t_hlen;
1133 
1134 			if (set_mtu) {
1135 				dev->mtu = rt->dst.dev->mtu - t_hlen;
1136 				if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1137 					dev->mtu -= 8;
1138 				if (dev->type == ARPHRD_ETHER)
1139 					dev->mtu -= ETH_HLEN;
1140 
1141 				if (dev->mtu < IPV6_MIN_MTU)
1142 					dev->mtu = IPV6_MIN_MTU;
1143 			}
1144 		}
1145 		ip6_rt_put(rt);
1146 	}
1147 }
1148 
1149 static int ip6gre_calc_hlen(struct ip6_tnl *tunnel)
1150 {
1151 	int t_hlen;
1152 
1153 	tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags);
1154 	tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen;
1155 
1156 	t_hlen = tunnel->hlen + sizeof(struct ipv6hdr);
1157 	tunnel->dev->hard_header_len = LL_MAX_HEADER + t_hlen;
1158 	return t_hlen;
1159 }
1160 
1161 static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu)
1162 {
1163 	ip6gre_tnl_link_config_common(t);
1164 	ip6gre_tnl_link_config_route(t, set_mtu, ip6gre_calc_hlen(t));
1165 }
1166 
1167 static void ip6gre_tnl_copy_tnl_parm(struct ip6_tnl *t,
1168 				     const struct __ip6_tnl_parm *p)
1169 {
1170 	t->parms.laddr = p->laddr;
1171 	t->parms.raddr = p->raddr;
1172 	t->parms.flags = p->flags;
1173 	t->parms.hop_limit = p->hop_limit;
1174 	t->parms.encap_limit = p->encap_limit;
1175 	t->parms.flowinfo = p->flowinfo;
1176 	t->parms.link = p->link;
1177 	t->parms.proto = p->proto;
1178 	t->parms.i_key = p->i_key;
1179 	t->parms.o_key = p->o_key;
1180 	t->parms.i_flags = p->i_flags;
1181 	t->parms.o_flags = p->o_flags;
1182 	t->parms.fwmark = p->fwmark;
1183 	dst_cache_reset(&t->dst_cache);
1184 }
1185 
1186 static int ip6gre_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p,
1187 			     int set_mtu)
1188 {
1189 	ip6gre_tnl_copy_tnl_parm(t, p);
1190 	ip6gre_tnl_link_config(t, set_mtu);
1191 	return 0;
1192 }
1193 
1194 static void ip6gre_tnl_parm_from_user(struct __ip6_tnl_parm *p,
1195 	const struct ip6_tnl_parm2 *u)
1196 {
1197 	p->laddr = u->laddr;
1198 	p->raddr = u->raddr;
1199 	p->flags = u->flags;
1200 	p->hop_limit = u->hop_limit;
1201 	p->encap_limit = u->encap_limit;
1202 	p->flowinfo = u->flowinfo;
1203 	p->link = u->link;
1204 	p->i_key = u->i_key;
1205 	p->o_key = u->o_key;
1206 	p->i_flags = gre_flags_to_tnl_flags(u->i_flags);
1207 	p->o_flags = gre_flags_to_tnl_flags(u->o_flags);
1208 	memcpy(p->name, u->name, sizeof(u->name));
1209 }
1210 
1211 static void ip6gre_tnl_parm_to_user(struct ip6_tnl_parm2 *u,
1212 	const struct __ip6_tnl_parm *p)
1213 {
1214 	u->proto = IPPROTO_GRE;
1215 	u->laddr = p->laddr;
1216 	u->raddr = p->raddr;
1217 	u->flags = p->flags;
1218 	u->hop_limit = p->hop_limit;
1219 	u->encap_limit = p->encap_limit;
1220 	u->flowinfo = p->flowinfo;
1221 	u->link = p->link;
1222 	u->i_key = p->i_key;
1223 	u->o_key = p->o_key;
1224 	u->i_flags = gre_tnl_flags_to_gre_flags(p->i_flags);
1225 	u->o_flags = gre_tnl_flags_to_gre_flags(p->o_flags);
1226 	memcpy(u->name, p->name, sizeof(u->name));
1227 }
1228 
1229 static int ip6gre_tunnel_ioctl(struct net_device *dev,
1230 	struct ifreq *ifr, int cmd)
1231 {
1232 	int err = 0;
1233 	struct ip6_tnl_parm2 p;
1234 	struct __ip6_tnl_parm p1;
1235 	struct ip6_tnl *t = netdev_priv(dev);
1236 	struct net *net = t->net;
1237 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1238 
1239 	memset(&p1, 0, sizeof(p1));
1240 
1241 	switch (cmd) {
1242 	case SIOCGETTUNNEL:
1243 		if (dev == ign->fb_tunnel_dev) {
1244 			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1245 				err = -EFAULT;
1246 				break;
1247 			}
1248 			ip6gre_tnl_parm_from_user(&p1, &p);
1249 			t = ip6gre_tunnel_locate(net, &p1, 0);
1250 			if (!t)
1251 				t = netdev_priv(dev);
1252 		}
1253 		memset(&p, 0, sizeof(p));
1254 		ip6gre_tnl_parm_to_user(&p, &t->parms);
1255 		if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1256 			err = -EFAULT;
1257 		break;
1258 
1259 	case SIOCADDTUNNEL:
1260 	case SIOCCHGTUNNEL:
1261 		err = -EPERM;
1262 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1263 			goto done;
1264 
1265 		err = -EFAULT;
1266 		if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1267 			goto done;
1268 
1269 		err = -EINVAL;
1270 		if ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING))
1271 			goto done;
1272 
1273 		if (!(p.i_flags&GRE_KEY))
1274 			p.i_key = 0;
1275 		if (!(p.o_flags&GRE_KEY))
1276 			p.o_key = 0;
1277 
1278 		ip6gre_tnl_parm_from_user(&p1, &p);
1279 		t = ip6gre_tunnel_locate(net, &p1, cmd == SIOCADDTUNNEL);
1280 
1281 		if (dev != ign->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
1282 			if (t) {
1283 				if (t->dev != dev) {
1284 					err = -EEXIST;
1285 					break;
1286 				}
1287 			} else {
1288 				t = netdev_priv(dev);
1289 
1290 				ip6gre_tunnel_unlink(ign, t);
1291 				synchronize_net();
1292 				ip6gre_tnl_change(t, &p1, 1);
1293 				ip6gre_tunnel_link(ign, t);
1294 				netdev_state_change(dev);
1295 			}
1296 		}
1297 
1298 		if (t) {
1299 			err = 0;
1300 
1301 			memset(&p, 0, sizeof(p));
1302 			ip6gre_tnl_parm_to_user(&p, &t->parms);
1303 			if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1304 				err = -EFAULT;
1305 		} else
1306 			err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1307 		break;
1308 
1309 	case SIOCDELTUNNEL:
1310 		err = -EPERM;
1311 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1312 			goto done;
1313 
1314 		if (dev == ign->fb_tunnel_dev) {
1315 			err = -EFAULT;
1316 			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1317 				goto done;
1318 			err = -ENOENT;
1319 			ip6gre_tnl_parm_from_user(&p1, &p);
1320 			t = ip6gre_tunnel_locate(net, &p1, 0);
1321 			if (!t)
1322 				goto done;
1323 			err = -EPERM;
1324 			if (t == netdev_priv(ign->fb_tunnel_dev))
1325 				goto done;
1326 			dev = t->dev;
1327 		}
1328 		unregister_netdevice(dev);
1329 		err = 0;
1330 		break;
1331 
1332 	default:
1333 		err = -EINVAL;
1334 	}
1335 
1336 done:
1337 	return err;
1338 }
1339 
1340 static int ip6gre_header(struct sk_buff *skb, struct net_device *dev,
1341 			 unsigned short type, const void *daddr,
1342 			 const void *saddr, unsigned int len)
1343 {
1344 	struct ip6_tnl *t = netdev_priv(dev);
1345 	struct ipv6hdr *ipv6h;
1346 	__be16 *p;
1347 
1348 	ipv6h = skb_push(skb, t->hlen + sizeof(*ipv6h));
1349 	ip6_flow_hdr(ipv6h, 0, ip6_make_flowlabel(dev_net(dev), skb,
1350 						  t->fl.u.ip6.flowlabel,
1351 						  true, &t->fl.u.ip6));
1352 	ipv6h->hop_limit = t->parms.hop_limit;
1353 	ipv6h->nexthdr = NEXTHDR_GRE;
1354 	ipv6h->saddr = t->parms.laddr;
1355 	ipv6h->daddr = t->parms.raddr;
1356 
1357 	p = (__be16 *)(ipv6h + 1);
1358 	p[0] = t->parms.o_flags;
1359 	p[1] = htons(type);
1360 
1361 	/*
1362 	 *	Set the source hardware address.
1363 	 */
1364 
1365 	if (saddr)
1366 		memcpy(&ipv6h->saddr, saddr, sizeof(struct in6_addr));
1367 	if (daddr)
1368 		memcpy(&ipv6h->daddr, daddr, sizeof(struct in6_addr));
1369 	if (!ipv6_addr_any(&ipv6h->daddr))
1370 		return t->hlen;
1371 
1372 	return -t->hlen;
1373 }
1374 
1375 static const struct header_ops ip6gre_header_ops = {
1376 	.create	= ip6gre_header,
1377 };
1378 
1379 static const struct net_device_ops ip6gre_netdev_ops = {
1380 	.ndo_init		= ip6gre_tunnel_init,
1381 	.ndo_uninit		= ip6gre_tunnel_uninit,
1382 	.ndo_start_xmit		= ip6gre_tunnel_xmit,
1383 	.ndo_do_ioctl		= ip6gre_tunnel_ioctl,
1384 	.ndo_change_mtu		= ip6_tnl_change_mtu,
1385 	.ndo_get_stats64	= ip_tunnel_get_stats64,
1386 	.ndo_get_iflink		= ip6_tnl_get_iflink,
1387 };
1388 
1389 static void ip6gre_dev_free(struct net_device *dev)
1390 {
1391 	struct ip6_tnl *t = netdev_priv(dev);
1392 
1393 	gro_cells_destroy(&t->gro_cells);
1394 	dst_cache_destroy(&t->dst_cache);
1395 	free_percpu(dev->tstats);
1396 }
1397 
1398 static void ip6gre_tunnel_setup(struct net_device *dev)
1399 {
1400 	dev->netdev_ops = &ip6gre_netdev_ops;
1401 	dev->needs_free_netdev = true;
1402 	dev->priv_destructor = ip6gre_dev_free;
1403 
1404 	dev->type = ARPHRD_IP6GRE;
1405 
1406 	dev->flags |= IFF_NOARP;
1407 	dev->addr_len = sizeof(struct in6_addr);
1408 	netif_keep_dst(dev);
1409 	/* This perm addr will be used as interface identifier by IPv6 */
1410 	dev->addr_assign_type = NET_ADDR_RANDOM;
1411 	eth_random_addr(dev->perm_addr);
1412 }
1413 
1414 #define GRE6_FEATURES (NETIF_F_SG |		\
1415 		       NETIF_F_FRAGLIST |	\
1416 		       NETIF_F_HIGHDMA |	\
1417 		       NETIF_F_HW_CSUM)
1418 
1419 static void ip6gre_tnl_init_features(struct net_device *dev)
1420 {
1421 	struct ip6_tnl *nt = netdev_priv(dev);
1422 
1423 	dev->features		|= GRE6_FEATURES;
1424 	dev->hw_features	|= GRE6_FEATURES;
1425 
1426 	if (!(nt->parms.o_flags & TUNNEL_SEQ)) {
1427 		/* TCP offload with GRE SEQ is not supported, nor
1428 		 * can we support 2 levels of outer headers requiring
1429 		 * an update.
1430 		 */
1431 		if (!(nt->parms.o_flags & TUNNEL_CSUM) ||
1432 		    nt->encap.type == TUNNEL_ENCAP_NONE) {
1433 			dev->features    |= NETIF_F_GSO_SOFTWARE;
1434 			dev->hw_features |= NETIF_F_GSO_SOFTWARE;
1435 		}
1436 
1437 		/* Can use a lockless transmit, unless we generate
1438 		 * output sequences
1439 		 */
1440 		dev->features |= NETIF_F_LLTX;
1441 	}
1442 }
1443 
1444 static int ip6gre_tunnel_init_common(struct net_device *dev)
1445 {
1446 	struct ip6_tnl *tunnel;
1447 	int ret;
1448 	int t_hlen;
1449 
1450 	tunnel = netdev_priv(dev);
1451 
1452 	tunnel->dev = dev;
1453 	tunnel->net = dev_net(dev);
1454 	strcpy(tunnel->parms.name, dev->name);
1455 
1456 	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1457 	if (!dev->tstats)
1458 		return -ENOMEM;
1459 
1460 	ret = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL);
1461 	if (ret)
1462 		goto cleanup_alloc_pcpu_stats;
1463 
1464 	ret = gro_cells_init(&tunnel->gro_cells, dev);
1465 	if (ret)
1466 		goto cleanup_dst_cache_init;
1467 
1468 	t_hlen = ip6gre_calc_hlen(tunnel);
1469 	dev->mtu = ETH_DATA_LEN - t_hlen;
1470 	if (dev->type == ARPHRD_ETHER)
1471 		dev->mtu -= ETH_HLEN;
1472 	if (!(tunnel->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1473 		dev->mtu -= 8;
1474 
1475 	if (tunnel->parms.collect_md) {
1476 		dev->features |= NETIF_F_NETNS_LOCAL;
1477 		netif_keep_dst(dev);
1478 	}
1479 	ip6gre_tnl_init_features(dev);
1480 
1481 	return 0;
1482 
1483 cleanup_dst_cache_init:
1484 	dst_cache_destroy(&tunnel->dst_cache);
1485 cleanup_alloc_pcpu_stats:
1486 	free_percpu(dev->tstats);
1487 	dev->tstats = NULL;
1488 	return ret;
1489 }
1490 
1491 static int ip6gre_tunnel_init(struct net_device *dev)
1492 {
1493 	struct ip6_tnl *tunnel;
1494 	int ret;
1495 
1496 	ret = ip6gre_tunnel_init_common(dev);
1497 	if (ret)
1498 		return ret;
1499 
1500 	tunnel = netdev_priv(dev);
1501 
1502 	if (tunnel->parms.collect_md)
1503 		return 0;
1504 
1505 	memcpy(dev->dev_addr, &tunnel->parms.laddr, sizeof(struct in6_addr));
1506 	memcpy(dev->broadcast, &tunnel->parms.raddr, sizeof(struct in6_addr));
1507 
1508 	if (ipv6_addr_any(&tunnel->parms.raddr))
1509 		dev->header_ops = &ip6gre_header_ops;
1510 
1511 	return 0;
1512 }
1513 
1514 static void ip6gre_fb_tunnel_init(struct net_device *dev)
1515 {
1516 	struct ip6_tnl *tunnel = netdev_priv(dev);
1517 
1518 	tunnel->dev = dev;
1519 	tunnel->net = dev_net(dev);
1520 	strcpy(tunnel->parms.name, dev->name);
1521 
1522 	tunnel->hlen		= sizeof(struct ipv6hdr) + 4;
1523 
1524 	dev_hold(dev);
1525 }
1526 
1527 static struct inet6_protocol ip6gre_protocol __read_mostly = {
1528 	.handler     = gre_rcv,
1529 	.err_handler = ip6gre_err,
1530 	.flags       = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1531 };
1532 
1533 static void ip6gre_destroy_tunnels(struct net *net, struct list_head *head)
1534 {
1535 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1536 	struct net_device *dev, *aux;
1537 	int prio;
1538 
1539 	for_each_netdev_safe(net, dev, aux)
1540 		if (dev->rtnl_link_ops == &ip6gre_link_ops ||
1541 		    dev->rtnl_link_ops == &ip6gre_tap_ops ||
1542 		    dev->rtnl_link_ops == &ip6erspan_tap_ops)
1543 			unregister_netdevice_queue(dev, head);
1544 
1545 	for (prio = 0; prio < 4; prio++) {
1546 		int h;
1547 		for (h = 0; h < IP6_GRE_HASH_SIZE; h++) {
1548 			struct ip6_tnl *t;
1549 
1550 			t = rtnl_dereference(ign->tunnels[prio][h]);
1551 
1552 			while (t) {
1553 				/* If dev is in the same netns, it has already
1554 				 * been added to the list by the previous loop.
1555 				 */
1556 				if (!net_eq(dev_net(t->dev), net))
1557 					unregister_netdevice_queue(t->dev,
1558 								   head);
1559 				t = rtnl_dereference(t->next);
1560 			}
1561 		}
1562 	}
1563 }
1564 
1565 static int __net_init ip6gre_init_net(struct net *net)
1566 {
1567 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1568 	int err;
1569 
1570 	if (!net_has_fallback_tunnels(net))
1571 		return 0;
1572 	ign->fb_tunnel_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6gre0",
1573 					  NET_NAME_UNKNOWN,
1574 					  ip6gre_tunnel_setup);
1575 	if (!ign->fb_tunnel_dev) {
1576 		err = -ENOMEM;
1577 		goto err_alloc_dev;
1578 	}
1579 	dev_net_set(ign->fb_tunnel_dev, net);
1580 	/* FB netdevice is special: we have one, and only one per netns.
1581 	 * Allowing to move it to another netns is clearly unsafe.
1582 	 */
1583 	ign->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
1584 
1585 
1586 	ip6gre_fb_tunnel_init(ign->fb_tunnel_dev);
1587 	ign->fb_tunnel_dev->rtnl_link_ops = &ip6gre_link_ops;
1588 
1589 	err = register_netdev(ign->fb_tunnel_dev);
1590 	if (err)
1591 		goto err_reg_dev;
1592 
1593 	rcu_assign_pointer(ign->tunnels_wc[0],
1594 			   netdev_priv(ign->fb_tunnel_dev));
1595 	return 0;
1596 
1597 err_reg_dev:
1598 	free_netdev(ign->fb_tunnel_dev);
1599 err_alloc_dev:
1600 	return err;
1601 }
1602 
1603 static void __net_exit ip6gre_exit_batch_net(struct list_head *net_list)
1604 {
1605 	struct net *net;
1606 	LIST_HEAD(list);
1607 
1608 	rtnl_lock();
1609 	list_for_each_entry(net, net_list, exit_list)
1610 		ip6gre_destroy_tunnels(net, &list);
1611 	unregister_netdevice_many(&list);
1612 	rtnl_unlock();
1613 }
1614 
1615 static struct pernet_operations ip6gre_net_ops = {
1616 	.init = ip6gre_init_net,
1617 	.exit_batch = ip6gre_exit_batch_net,
1618 	.id   = &ip6gre_net_id,
1619 	.size = sizeof(struct ip6gre_net),
1620 };
1621 
1622 static int ip6gre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[],
1623 				  struct netlink_ext_ack *extack)
1624 {
1625 	__be16 flags;
1626 
1627 	if (!data)
1628 		return 0;
1629 
1630 	flags = 0;
1631 	if (data[IFLA_GRE_IFLAGS])
1632 		flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1633 	if (data[IFLA_GRE_OFLAGS])
1634 		flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1635 	if (flags & (GRE_VERSION|GRE_ROUTING))
1636 		return -EINVAL;
1637 
1638 	return 0;
1639 }
1640 
1641 static int ip6gre_tap_validate(struct nlattr *tb[], struct nlattr *data[],
1642 			       struct netlink_ext_ack *extack)
1643 {
1644 	struct in6_addr daddr;
1645 
1646 	if (tb[IFLA_ADDRESS]) {
1647 		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1648 			return -EINVAL;
1649 		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1650 			return -EADDRNOTAVAIL;
1651 	}
1652 
1653 	if (!data)
1654 		goto out;
1655 
1656 	if (data[IFLA_GRE_REMOTE]) {
1657 		daddr = nla_get_in6_addr(data[IFLA_GRE_REMOTE]);
1658 		if (ipv6_addr_any(&daddr))
1659 			return -EINVAL;
1660 	}
1661 
1662 out:
1663 	return ip6gre_tunnel_validate(tb, data, extack);
1664 }
1665 
1666 static int ip6erspan_tap_validate(struct nlattr *tb[], struct nlattr *data[],
1667 				  struct netlink_ext_ack *extack)
1668 {
1669 	__be16 flags = 0;
1670 	int ret, ver = 0;
1671 
1672 	if (!data)
1673 		return 0;
1674 
1675 	ret = ip6gre_tap_validate(tb, data, extack);
1676 	if (ret)
1677 		return ret;
1678 
1679 	/* ERSPAN should only have GRE sequence and key flag */
1680 	if (data[IFLA_GRE_OFLAGS])
1681 		flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1682 	if (data[IFLA_GRE_IFLAGS])
1683 		flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1684 	if (!data[IFLA_GRE_COLLECT_METADATA] &&
1685 	    flags != (GRE_SEQ | GRE_KEY))
1686 		return -EINVAL;
1687 
1688 	/* ERSPAN Session ID only has 10-bit. Since we reuse
1689 	 * 32-bit key field as ID, check it's range.
1690 	 */
1691 	if (data[IFLA_GRE_IKEY] &&
1692 	    (ntohl(nla_get_be32(data[IFLA_GRE_IKEY])) & ~ID_MASK))
1693 		return -EINVAL;
1694 
1695 	if (data[IFLA_GRE_OKEY] &&
1696 	    (ntohl(nla_get_be32(data[IFLA_GRE_OKEY])) & ~ID_MASK))
1697 		return -EINVAL;
1698 
1699 	if (data[IFLA_GRE_ERSPAN_VER]) {
1700 		ver = nla_get_u8(data[IFLA_GRE_ERSPAN_VER]);
1701 		if (ver != 1 && ver != 2)
1702 			return -EINVAL;
1703 	}
1704 
1705 	if (ver == 1) {
1706 		if (data[IFLA_GRE_ERSPAN_INDEX]) {
1707 			u32 index = nla_get_u32(data[IFLA_GRE_ERSPAN_INDEX]);
1708 
1709 			if (index & ~INDEX_MASK)
1710 				return -EINVAL;
1711 		}
1712 	} else if (ver == 2) {
1713 		if (data[IFLA_GRE_ERSPAN_DIR]) {
1714 			u16 dir = nla_get_u8(data[IFLA_GRE_ERSPAN_DIR]);
1715 
1716 			if (dir & ~(DIR_MASK >> DIR_OFFSET))
1717 				return -EINVAL;
1718 		}
1719 
1720 		if (data[IFLA_GRE_ERSPAN_HWID]) {
1721 			u16 hwid = nla_get_u16(data[IFLA_GRE_ERSPAN_HWID]);
1722 
1723 			if (hwid & ~(HWID_MASK >> HWID_OFFSET))
1724 				return -EINVAL;
1725 		}
1726 	}
1727 
1728 	return 0;
1729 }
1730 
1731 static void ip6gre_netlink_parms(struct nlattr *data[],
1732 				struct __ip6_tnl_parm *parms)
1733 {
1734 	memset(parms, 0, sizeof(*parms));
1735 
1736 	if (!data)
1737 		return;
1738 
1739 	if (data[IFLA_GRE_LINK])
1740 		parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
1741 
1742 	if (data[IFLA_GRE_IFLAGS])
1743 		parms->i_flags = gre_flags_to_tnl_flags(
1744 				nla_get_be16(data[IFLA_GRE_IFLAGS]));
1745 
1746 	if (data[IFLA_GRE_OFLAGS])
1747 		parms->o_flags = gre_flags_to_tnl_flags(
1748 				nla_get_be16(data[IFLA_GRE_OFLAGS]));
1749 
1750 	if (data[IFLA_GRE_IKEY])
1751 		parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
1752 
1753 	if (data[IFLA_GRE_OKEY])
1754 		parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
1755 
1756 	if (data[IFLA_GRE_LOCAL])
1757 		parms->laddr = nla_get_in6_addr(data[IFLA_GRE_LOCAL]);
1758 
1759 	if (data[IFLA_GRE_REMOTE])
1760 		parms->raddr = nla_get_in6_addr(data[IFLA_GRE_REMOTE]);
1761 
1762 	if (data[IFLA_GRE_TTL])
1763 		parms->hop_limit = nla_get_u8(data[IFLA_GRE_TTL]);
1764 
1765 	if (data[IFLA_GRE_ENCAP_LIMIT])
1766 		parms->encap_limit = nla_get_u8(data[IFLA_GRE_ENCAP_LIMIT]);
1767 
1768 	if (data[IFLA_GRE_FLOWINFO])
1769 		parms->flowinfo = nla_get_be32(data[IFLA_GRE_FLOWINFO]);
1770 
1771 	if (data[IFLA_GRE_FLAGS])
1772 		parms->flags = nla_get_u32(data[IFLA_GRE_FLAGS]);
1773 
1774 	if (data[IFLA_GRE_FWMARK])
1775 		parms->fwmark = nla_get_u32(data[IFLA_GRE_FWMARK]);
1776 
1777 	if (data[IFLA_GRE_COLLECT_METADATA])
1778 		parms->collect_md = true;
1779 
1780 	if (data[IFLA_GRE_ERSPAN_VER])
1781 		parms->erspan_ver = nla_get_u8(data[IFLA_GRE_ERSPAN_VER]);
1782 
1783 	if (parms->erspan_ver == 1) {
1784 		if (data[IFLA_GRE_ERSPAN_INDEX])
1785 			parms->index = nla_get_u32(data[IFLA_GRE_ERSPAN_INDEX]);
1786 	} else if (parms->erspan_ver == 2) {
1787 		if (data[IFLA_GRE_ERSPAN_DIR])
1788 			parms->dir = nla_get_u8(data[IFLA_GRE_ERSPAN_DIR]);
1789 		if (data[IFLA_GRE_ERSPAN_HWID])
1790 			parms->hwid = nla_get_u16(data[IFLA_GRE_ERSPAN_HWID]);
1791 	}
1792 }
1793 
1794 static int ip6gre_tap_init(struct net_device *dev)
1795 {
1796 	int ret;
1797 
1798 	ret = ip6gre_tunnel_init_common(dev);
1799 	if (ret)
1800 		return ret;
1801 
1802 	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1803 
1804 	return 0;
1805 }
1806 
1807 static const struct net_device_ops ip6gre_tap_netdev_ops = {
1808 	.ndo_init = ip6gre_tap_init,
1809 	.ndo_uninit = ip6gre_tunnel_uninit,
1810 	.ndo_start_xmit = ip6gre_tunnel_xmit,
1811 	.ndo_set_mac_address = eth_mac_addr,
1812 	.ndo_validate_addr = eth_validate_addr,
1813 	.ndo_change_mtu = ip6_tnl_change_mtu,
1814 	.ndo_get_stats64 = ip_tunnel_get_stats64,
1815 	.ndo_get_iflink = ip6_tnl_get_iflink,
1816 };
1817 
1818 static int ip6erspan_calc_hlen(struct ip6_tnl *tunnel)
1819 {
1820 	int t_hlen;
1821 
1822 	tunnel->tun_hlen = 8;
1823 	tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen +
1824 		       erspan_hdr_len(tunnel->parms.erspan_ver);
1825 
1826 	t_hlen = tunnel->hlen + sizeof(struct ipv6hdr);
1827 	tunnel->dev->hard_header_len = LL_MAX_HEADER + t_hlen;
1828 	return t_hlen;
1829 }
1830 
1831 static int ip6erspan_tap_init(struct net_device *dev)
1832 {
1833 	struct ip6_tnl *tunnel;
1834 	int t_hlen;
1835 	int ret;
1836 
1837 	tunnel = netdev_priv(dev);
1838 
1839 	tunnel->dev = dev;
1840 	tunnel->net = dev_net(dev);
1841 	strcpy(tunnel->parms.name, dev->name);
1842 
1843 	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1844 	if (!dev->tstats)
1845 		return -ENOMEM;
1846 
1847 	ret = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL);
1848 	if (ret)
1849 		goto cleanup_alloc_pcpu_stats;
1850 
1851 	ret = gro_cells_init(&tunnel->gro_cells, dev);
1852 	if (ret)
1853 		goto cleanup_dst_cache_init;
1854 
1855 	t_hlen = ip6erspan_calc_hlen(tunnel);
1856 	dev->mtu = ETH_DATA_LEN - t_hlen;
1857 	if (dev->type == ARPHRD_ETHER)
1858 		dev->mtu -= ETH_HLEN;
1859 	if (!(tunnel->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1860 		dev->mtu -= 8;
1861 
1862 	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1863 	ip6erspan_tnl_link_config(tunnel, 1);
1864 
1865 	return 0;
1866 
1867 cleanup_dst_cache_init:
1868 	dst_cache_destroy(&tunnel->dst_cache);
1869 cleanup_alloc_pcpu_stats:
1870 	free_percpu(dev->tstats);
1871 	dev->tstats = NULL;
1872 	return ret;
1873 }
1874 
1875 static const struct net_device_ops ip6erspan_netdev_ops = {
1876 	.ndo_init =		ip6erspan_tap_init,
1877 	.ndo_uninit =		ip6erspan_tunnel_uninit,
1878 	.ndo_start_xmit =	ip6erspan_tunnel_xmit,
1879 	.ndo_set_mac_address =	eth_mac_addr,
1880 	.ndo_validate_addr =	eth_validate_addr,
1881 	.ndo_change_mtu =	ip6_tnl_change_mtu,
1882 	.ndo_get_stats64 =	ip_tunnel_get_stats64,
1883 	.ndo_get_iflink =	ip6_tnl_get_iflink,
1884 };
1885 
1886 static void ip6gre_tap_setup(struct net_device *dev)
1887 {
1888 
1889 	ether_setup(dev);
1890 
1891 	dev->max_mtu = 0;
1892 	dev->netdev_ops = &ip6gre_tap_netdev_ops;
1893 	dev->needs_free_netdev = true;
1894 	dev->priv_destructor = ip6gre_dev_free;
1895 
1896 	dev->features |= NETIF_F_NETNS_LOCAL;
1897 	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1898 	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1899 	netif_keep_dst(dev);
1900 }
1901 
1902 bool is_ip6gretap_dev(const struct net_device *dev)
1903 {
1904 	return dev->netdev_ops == &ip6gre_tap_netdev_ops;
1905 }
1906 EXPORT_SYMBOL_GPL(is_ip6gretap_dev);
1907 
1908 static bool ip6gre_netlink_encap_parms(struct nlattr *data[],
1909 				       struct ip_tunnel_encap *ipencap)
1910 {
1911 	bool ret = false;
1912 
1913 	memset(ipencap, 0, sizeof(*ipencap));
1914 
1915 	if (!data)
1916 		return ret;
1917 
1918 	if (data[IFLA_GRE_ENCAP_TYPE]) {
1919 		ret = true;
1920 		ipencap->type = nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]);
1921 	}
1922 
1923 	if (data[IFLA_GRE_ENCAP_FLAGS]) {
1924 		ret = true;
1925 		ipencap->flags = nla_get_u16(data[IFLA_GRE_ENCAP_FLAGS]);
1926 	}
1927 
1928 	if (data[IFLA_GRE_ENCAP_SPORT]) {
1929 		ret = true;
1930 		ipencap->sport = nla_get_be16(data[IFLA_GRE_ENCAP_SPORT]);
1931 	}
1932 
1933 	if (data[IFLA_GRE_ENCAP_DPORT]) {
1934 		ret = true;
1935 		ipencap->dport = nla_get_be16(data[IFLA_GRE_ENCAP_DPORT]);
1936 	}
1937 
1938 	return ret;
1939 }
1940 
1941 static int ip6gre_newlink_common(struct net *src_net, struct net_device *dev,
1942 				 struct nlattr *tb[], struct nlattr *data[],
1943 				 struct netlink_ext_ack *extack)
1944 {
1945 	struct ip6_tnl *nt;
1946 	struct ip_tunnel_encap ipencap;
1947 	int err;
1948 
1949 	nt = netdev_priv(dev);
1950 
1951 	if (ip6gre_netlink_encap_parms(data, &ipencap)) {
1952 		int err = ip6_tnl_encap_setup(nt, &ipencap);
1953 
1954 		if (err < 0)
1955 			return err;
1956 	}
1957 
1958 	if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
1959 		eth_hw_addr_random(dev);
1960 
1961 	nt->dev = dev;
1962 	nt->net = dev_net(dev);
1963 
1964 	err = register_netdevice(dev);
1965 	if (err)
1966 		goto out;
1967 
1968 	if (tb[IFLA_MTU])
1969 		ip6_tnl_change_mtu(dev, nla_get_u32(tb[IFLA_MTU]));
1970 
1971 	dev_hold(dev);
1972 
1973 out:
1974 	return err;
1975 }
1976 
1977 static int ip6gre_newlink(struct net *src_net, struct net_device *dev,
1978 			  struct nlattr *tb[], struct nlattr *data[],
1979 			  struct netlink_ext_ack *extack)
1980 {
1981 	struct ip6_tnl *nt = netdev_priv(dev);
1982 	struct net *net = dev_net(dev);
1983 	struct ip6gre_net *ign;
1984 	int err;
1985 
1986 	ip6gre_netlink_parms(data, &nt->parms);
1987 	ign = net_generic(net, ip6gre_net_id);
1988 
1989 	if (nt->parms.collect_md) {
1990 		if (rtnl_dereference(ign->collect_md_tun))
1991 			return -EEXIST;
1992 	} else {
1993 		if (ip6gre_tunnel_find(net, &nt->parms, dev->type))
1994 			return -EEXIST;
1995 	}
1996 
1997 	err = ip6gre_newlink_common(src_net, dev, tb, data, extack);
1998 	if (!err) {
1999 		ip6gre_tnl_link_config(nt, !tb[IFLA_MTU]);
2000 		ip6gre_tunnel_link_md(ign, nt);
2001 		ip6gre_tunnel_link(net_generic(net, ip6gre_net_id), nt);
2002 	}
2003 	return err;
2004 }
2005 
2006 static struct ip6_tnl *
2007 ip6gre_changelink_common(struct net_device *dev, struct nlattr *tb[],
2008 			 struct nlattr *data[], struct __ip6_tnl_parm *p_p,
2009 			 struct netlink_ext_ack *extack)
2010 {
2011 	struct ip6_tnl *t, *nt = netdev_priv(dev);
2012 	struct net *net = nt->net;
2013 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
2014 	struct ip_tunnel_encap ipencap;
2015 
2016 	if (dev == ign->fb_tunnel_dev)
2017 		return ERR_PTR(-EINVAL);
2018 
2019 	if (ip6gre_netlink_encap_parms(data, &ipencap)) {
2020 		int err = ip6_tnl_encap_setup(nt, &ipencap);
2021 
2022 		if (err < 0)
2023 			return ERR_PTR(err);
2024 	}
2025 
2026 	ip6gre_netlink_parms(data, p_p);
2027 
2028 	t = ip6gre_tunnel_locate(net, p_p, 0);
2029 
2030 	if (t) {
2031 		if (t->dev != dev)
2032 			return ERR_PTR(-EEXIST);
2033 	} else {
2034 		t = nt;
2035 	}
2036 
2037 	return t;
2038 }
2039 
2040 static int ip6gre_changelink(struct net_device *dev, struct nlattr *tb[],
2041 			     struct nlattr *data[],
2042 			     struct netlink_ext_ack *extack)
2043 {
2044 	struct ip6gre_net *ign = net_generic(dev_net(dev), ip6gre_net_id);
2045 	struct __ip6_tnl_parm p;
2046 	struct ip6_tnl *t;
2047 
2048 	t = ip6gre_changelink_common(dev, tb, data, &p, extack);
2049 	if (IS_ERR(t))
2050 		return PTR_ERR(t);
2051 
2052 	ip6gre_tunnel_unlink_md(ign, t);
2053 	ip6gre_tunnel_unlink(ign, t);
2054 	ip6gre_tnl_change(t, &p, !tb[IFLA_MTU]);
2055 	ip6gre_tunnel_link_md(ign, t);
2056 	ip6gre_tunnel_link(ign, t);
2057 	return 0;
2058 }
2059 
2060 static void ip6gre_dellink(struct net_device *dev, struct list_head *head)
2061 {
2062 	struct net *net = dev_net(dev);
2063 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
2064 
2065 	if (dev != ign->fb_tunnel_dev)
2066 		unregister_netdevice_queue(dev, head);
2067 }
2068 
2069 static size_t ip6gre_get_size(const struct net_device *dev)
2070 {
2071 	return
2072 		/* IFLA_GRE_LINK */
2073 		nla_total_size(4) +
2074 		/* IFLA_GRE_IFLAGS */
2075 		nla_total_size(2) +
2076 		/* IFLA_GRE_OFLAGS */
2077 		nla_total_size(2) +
2078 		/* IFLA_GRE_IKEY */
2079 		nla_total_size(4) +
2080 		/* IFLA_GRE_OKEY */
2081 		nla_total_size(4) +
2082 		/* IFLA_GRE_LOCAL */
2083 		nla_total_size(sizeof(struct in6_addr)) +
2084 		/* IFLA_GRE_REMOTE */
2085 		nla_total_size(sizeof(struct in6_addr)) +
2086 		/* IFLA_GRE_TTL */
2087 		nla_total_size(1) +
2088 		/* IFLA_GRE_ENCAP_LIMIT */
2089 		nla_total_size(1) +
2090 		/* IFLA_GRE_FLOWINFO */
2091 		nla_total_size(4) +
2092 		/* IFLA_GRE_FLAGS */
2093 		nla_total_size(4) +
2094 		/* IFLA_GRE_ENCAP_TYPE */
2095 		nla_total_size(2) +
2096 		/* IFLA_GRE_ENCAP_FLAGS */
2097 		nla_total_size(2) +
2098 		/* IFLA_GRE_ENCAP_SPORT */
2099 		nla_total_size(2) +
2100 		/* IFLA_GRE_ENCAP_DPORT */
2101 		nla_total_size(2) +
2102 		/* IFLA_GRE_COLLECT_METADATA */
2103 		nla_total_size(0) +
2104 		/* IFLA_GRE_FWMARK */
2105 		nla_total_size(4) +
2106 		/* IFLA_GRE_ERSPAN_INDEX */
2107 		nla_total_size(4) +
2108 		0;
2109 }
2110 
2111 static int ip6gre_fill_info(struct sk_buff *skb, const struct net_device *dev)
2112 {
2113 	struct ip6_tnl *t = netdev_priv(dev);
2114 	struct __ip6_tnl_parm *p = &t->parms;
2115 
2116 	if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
2117 	    nla_put_be16(skb, IFLA_GRE_IFLAGS,
2118 			 gre_tnl_flags_to_gre_flags(p->i_flags)) ||
2119 	    nla_put_be16(skb, IFLA_GRE_OFLAGS,
2120 			 gre_tnl_flags_to_gre_flags(p->o_flags)) ||
2121 	    nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
2122 	    nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
2123 	    nla_put_in6_addr(skb, IFLA_GRE_LOCAL, &p->laddr) ||
2124 	    nla_put_in6_addr(skb, IFLA_GRE_REMOTE, &p->raddr) ||
2125 	    nla_put_u8(skb, IFLA_GRE_TTL, p->hop_limit) ||
2126 	    nla_put_u8(skb, IFLA_GRE_ENCAP_LIMIT, p->encap_limit) ||
2127 	    nla_put_be32(skb, IFLA_GRE_FLOWINFO, p->flowinfo) ||
2128 	    nla_put_u32(skb, IFLA_GRE_FLAGS, p->flags) ||
2129 	    nla_put_u32(skb, IFLA_GRE_FWMARK, p->fwmark) ||
2130 	    nla_put_u32(skb, IFLA_GRE_ERSPAN_INDEX, p->index))
2131 		goto nla_put_failure;
2132 
2133 	if (nla_put_u16(skb, IFLA_GRE_ENCAP_TYPE,
2134 			t->encap.type) ||
2135 	    nla_put_be16(skb, IFLA_GRE_ENCAP_SPORT,
2136 			 t->encap.sport) ||
2137 	    nla_put_be16(skb, IFLA_GRE_ENCAP_DPORT,
2138 			 t->encap.dport) ||
2139 	    nla_put_u16(skb, IFLA_GRE_ENCAP_FLAGS,
2140 			t->encap.flags))
2141 		goto nla_put_failure;
2142 
2143 	if (p->collect_md) {
2144 		if (nla_put_flag(skb, IFLA_GRE_COLLECT_METADATA))
2145 			goto nla_put_failure;
2146 	}
2147 
2148 	if (nla_put_u8(skb, IFLA_GRE_ERSPAN_VER, p->erspan_ver))
2149 		goto nla_put_failure;
2150 
2151 	if (p->erspan_ver == 1) {
2152 		if (nla_put_u32(skb, IFLA_GRE_ERSPAN_INDEX, p->index))
2153 			goto nla_put_failure;
2154 	} else if (p->erspan_ver == 2) {
2155 		if (nla_put_u8(skb, IFLA_GRE_ERSPAN_DIR, p->dir))
2156 			goto nla_put_failure;
2157 		if (nla_put_u16(skb, IFLA_GRE_ERSPAN_HWID, p->hwid))
2158 			goto nla_put_failure;
2159 	}
2160 
2161 	return 0;
2162 
2163 nla_put_failure:
2164 	return -EMSGSIZE;
2165 }
2166 
2167 static const struct nla_policy ip6gre_policy[IFLA_GRE_MAX + 1] = {
2168 	[IFLA_GRE_LINK]        = { .type = NLA_U32 },
2169 	[IFLA_GRE_IFLAGS]      = { .type = NLA_U16 },
2170 	[IFLA_GRE_OFLAGS]      = { .type = NLA_U16 },
2171 	[IFLA_GRE_IKEY]        = { .type = NLA_U32 },
2172 	[IFLA_GRE_OKEY]        = { .type = NLA_U32 },
2173 	[IFLA_GRE_LOCAL]       = { .len = FIELD_SIZEOF(struct ipv6hdr, saddr) },
2174 	[IFLA_GRE_REMOTE]      = { .len = FIELD_SIZEOF(struct ipv6hdr, daddr) },
2175 	[IFLA_GRE_TTL]         = { .type = NLA_U8 },
2176 	[IFLA_GRE_ENCAP_LIMIT] = { .type = NLA_U8 },
2177 	[IFLA_GRE_FLOWINFO]    = { .type = NLA_U32 },
2178 	[IFLA_GRE_FLAGS]       = { .type = NLA_U32 },
2179 	[IFLA_GRE_ENCAP_TYPE]   = { .type = NLA_U16 },
2180 	[IFLA_GRE_ENCAP_FLAGS]  = { .type = NLA_U16 },
2181 	[IFLA_GRE_ENCAP_SPORT]  = { .type = NLA_U16 },
2182 	[IFLA_GRE_ENCAP_DPORT]  = { .type = NLA_U16 },
2183 	[IFLA_GRE_COLLECT_METADATA] = { .type = NLA_FLAG },
2184 	[IFLA_GRE_FWMARK]       = { .type = NLA_U32 },
2185 	[IFLA_GRE_ERSPAN_INDEX] = { .type = NLA_U32 },
2186 	[IFLA_GRE_ERSPAN_VER]	= { .type = NLA_U8 },
2187 	[IFLA_GRE_ERSPAN_DIR]	= { .type = NLA_U8 },
2188 	[IFLA_GRE_ERSPAN_HWID]	= { .type = NLA_U16 },
2189 };
2190 
2191 static void ip6erspan_tap_setup(struct net_device *dev)
2192 {
2193 	ether_setup(dev);
2194 
2195 	dev->netdev_ops = &ip6erspan_netdev_ops;
2196 	dev->needs_free_netdev = true;
2197 	dev->priv_destructor = ip6gre_dev_free;
2198 
2199 	dev->features |= NETIF_F_NETNS_LOCAL;
2200 	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
2201 	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
2202 	netif_keep_dst(dev);
2203 }
2204 
2205 static int ip6erspan_newlink(struct net *src_net, struct net_device *dev,
2206 			     struct nlattr *tb[], struct nlattr *data[],
2207 			     struct netlink_ext_ack *extack)
2208 {
2209 	struct ip6_tnl *nt = netdev_priv(dev);
2210 	struct net *net = dev_net(dev);
2211 	struct ip6gre_net *ign;
2212 	int err;
2213 
2214 	ip6gre_netlink_parms(data, &nt->parms);
2215 	ign = net_generic(net, ip6gre_net_id);
2216 
2217 	if (nt->parms.collect_md) {
2218 		if (rtnl_dereference(ign->collect_md_tun_erspan))
2219 			return -EEXIST;
2220 	} else {
2221 		if (ip6gre_tunnel_find(net, &nt->parms, dev->type))
2222 			return -EEXIST;
2223 	}
2224 
2225 	err = ip6gre_newlink_common(src_net, dev, tb, data, extack);
2226 	if (!err) {
2227 		ip6erspan_tnl_link_config(nt, !tb[IFLA_MTU]);
2228 		ip6erspan_tunnel_link_md(ign, nt);
2229 		ip6gre_tunnel_link(net_generic(net, ip6gre_net_id), nt);
2230 	}
2231 	return err;
2232 }
2233 
2234 static void ip6erspan_tnl_link_config(struct ip6_tnl *t, int set_mtu)
2235 {
2236 	ip6gre_tnl_link_config_common(t);
2237 	ip6gre_tnl_link_config_route(t, set_mtu, ip6erspan_calc_hlen(t));
2238 }
2239 
2240 static int ip6erspan_tnl_change(struct ip6_tnl *t,
2241 				const struct __ip6_tnl_parm *p, int set_mtu)
2242 {
2243 	ip6gre_tnl_copy_tnl_parm(t, p);
2244 	ip6erspan_tnl_link_config(t, set_mtu);
2245 	return 0;
2246 }
2247 
2248 static int ip6erspan_changelink(struct net_device *dev, struct nlattr *tb[],
2249 				struct nlattr *data[],
2250 				struct netlink_ext_ack *extack)
2251 {
2252 	struct ip6gre_net *ign = net_generic(dev_net(dev), ip6gre_net_id);
2253 	struct __ip6_tnl_parm p;
2254 	struct ip6_tnl *t;
2255 
2256 	t = ip6gre_changelink_common(dev, tb, data, &p, extack);
2257 	if (IS_ERR(t))
2258 		return PTR_ERR(t);
2259 
2260 	ip6gre_tunnel_unlink_md(ign, t);
2261 	ip6gre_tunnel_unlink(ign, t);
2262 	ip6erspan_tnl_change(t, &p, !tb[IFLA_MTU]);
2263 	ip6erspan_tunnel_link_md(ign, t);
2264 	ip6gre_tunnel_link(ign, t);
2265 	return 0;
2266 }
2267 
2268 static struct rtnl_link_ops ip6gre_link_ops __read_mostly = {
2269 	.kind		= "ip6gre",
2270 	.maxtype	= IFLA_GRE_MAX,
2271 	.policy		= ip6gre_policy,
2272 	.priv_size	= sizeof(struct ip6_tnl),
2273 	.setup		= ip6gre_tunnel_setup,
2274 	.validate	= ip6gre_tunnel_validate,
2275 	.newlink	= ip6gre_newlink,
2276 	.changelink	= ip6gre_changelink,
2277 	.dellink	= ip6gre_dellink,
2278 	.get_size	= ip6gre_get_size,
2279 	.fill_info	= ip6gre_fill_info,
2280 	.get_link_net	= ip6_tnl_get_link_net,
2281 };
2282 
2283 static struct rtnl_link_ops ip6gre_tap_ops __read_mostly = {
2284 	.kind		= "ip6gretap",
2285 	.maxtype	= IFLA_GRE_MAX,
2286 	.policy		= ip6gre_policy,
2287 	.priv_size	= sizeof(struct ip6_tnl),
2288 	.setup		= ip6gre_tap_setup,
2289 	.validate	= ip6gre_tap_validate,
2290 	.newlink	= ip6gre_newlink,
2291 	.changelink	= ip6gre_changelink,
2292 	.get_size	= ip6gre_get_size,
2293 	.fill_info	= ip6gre_fill_info,
2294 	.get_link_net	= ip6_tnl_get_link_net,
2295 };
2296 
2297 static struct rtnl_link_ops ip6erspan_tap_ops __read_mostly = {
2298 	.kind		= "ip6erspan",
2299 	.maxtype	= IFLA_GRE_MAX,
2300 	.policy		= ip6gre_policy,
2301 	.priv_size	= sizeof(struct ip6_tnl),
2302 	.setup		= ip6erspan_tap_setup,
2303 	.validate	= ip6erspan_tap_validate,
2304 	.newlink	= ip6erspan_newlink,
2305 	.changelink	= ip6erspan_changelink,
2306 	.get_size	= ip6gre_get_size,
2307 	.fill_info	= ip6gre_fill_info,
2308 	.get_link_net	= ip6_tnl_get_link_net,
2309 };
2310 
2311 /*
2312  *	And now the modules code and kernel interface.
2313  */
2314 
2315 static int __init ip6gre_init(void)
2316 {
2317 	int err;
2318 
2319 	pr_info("GRE over IPv6 tunneling driver\n");
2320 
2321 	err = register_pernet_device(&ip6gre_net_ops);
2322 	if (err < 0)
2323 		return err;
2324 
2325 	err = inet6_add_protocol(&ip6gre_protocol, IPPROTO_GRE);
2326 	if (err < 0) {
2327 		pr_info("%s: can't add protocol\n", __func__);
2328 		goto add_proto_failed;
2329 	}
2330 
2331 	err = rtnl_link_register(&ip6gre_link_ops);
2332 	if (err < 0)
2333 		goto rtnl_link_failed;
2334 
2335 	err = rtnl_link_register(&ip6gre_tap_ops);
2336 	if (err < 0)
2337 		goto tap_ops_failed;
2338 
2339 	err = rtnl_link_register(&ip6erspan_tap_ops);
2340 	if (err < 0)
2341 		goto erspan_link_failed;
2342 
2343 out:
2344 	return err;
2345 
2346 erspan_link_failed:
2347 	rtnl_link_unregister(&ip6gre_tap_ops);
2348 tap_ops_failed:
2349 	rtnl_link_unregister(&ip6gre_link_ops);
2350 rtnl_link_failed:
2351 	inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
2352 add_proto_failed:
2353 	unregister_pernet_device(&ip6gre_net_ops);
2354 	goto out;
2355 }
2356 
2357 static void __exit ip6gre_fini(void)
2358 {
2359 	rtnl_link_unregister(&ip6gre_tap_ops);
2360 	rtnl_link_unregister(&ip6gre_link_ops);
2361 	rtnl_link_unregister(&ip6erspan_tap_ops);
2362 	inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
2363 	unregister_pernet_device(&ip6gre_net_ops);
2364 }
2365 
2366 module_init(ip6gre_init);
2367 module_exit(ip6gre_fini);
2368 MODULE_LICENSE("GPL");
2369 MODULE_AUTHOR("D. Kozlov (xeb@mail.ru)");
2370 MODULE_DESCRIPTION("GRE over IPv6 tunneling device");
2371 MODULE_ALIAS_RTNL_LINK("ip6gre");
2372 MODULE_ALIAS_RTNL_LINK("ip6gretap");
2373 MODULE_ALIAS_RTNL_LINK("ip6erspan");
2374 MODULE_ALIAS_NETDEV("ip6gre0");
2375