xref: /openbmc/linux/net/ipv6/ip6_gre.c (revision 93f5715e)
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 ip6_tnl *t = netdev_priv(dev);
931 	struct dst_entry *dst = skb_dst(skb);
932 	struct net_device_stats *stats;
933 	bool truncate = false;
934 	int encap_limit = -1;
935 	__u8 dsfield = false;
936 	struct flowi6 fl6;
937 	int err = -EINVAL;
938 	__u32 mtu;
939 	int nhoff;
940 	int thoff;
941 
942 	if (!ip6_tnl_xmit_ctl(t, &t->parms.laddr, &t->parms.raddr))
943 		goto tx_err;
944 
945 	if (gre_handle_offloads(skb, false))
946 		goto tx_err;
947 
948 	if (skb->len > dev->mtu + dev->hard_header_len) {
949 		pskb_trim(skb, dev->mtu + dev->hard_header_len);
950 		truncate = true;
951 	}
952 
953 	nhoff = skb_network_header(skb) - skb_mac_header(skb);
954 	if (skb->protocol == htons(ETH_P_IP) &&
955 	    (ntohs(ip_hdr(skb)->tot_len) > skb->len - nhoff))
956 		truncate = true;
957 
958 	thoff = skb_transport_header(skb) - skb_mac_header(skb);
959 	if (skb->protocol == htons(ETH_P_IPV6) &&
960 	    (ntohs(ipv6_hdr(skb)->payload_len) > skb->len - thoff))
961 		truncate = true;
962 
963 	if (skb_cow_head(skb, dev->needed_headroom ?: t->hlen))
964 		goto tx_err;
965 
966 	t->parms.o_flags &= ~TUNNEL_KEY;
967 	IPCB(skb)->flags = 0;
968 
969 	/* For collect_md mode, derive fl6 from the tunnel key,
970 	 * for native mode, call prepare_ip6gre_xmit_{ipv4,ipv6}.
971 	 */
972 	if (t->parms.collect_md) {
973 		struct ip_tunnel_info *tun_info;
974 		const struct ip_tunnel_key *key;
975 		struct erspan_metadata *md;
976 		__be32 tun_id;
977 
978 		tun_info = skb_tunnel_info(skb);
979 		if (unlikely(!tun_info ||
980 			     !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
981 			     ip_tunnel_info_af(tun_info) != AF_INET6))
982 			return -EINVAL;
983 
984 		key = &tun_info->key;
985 		memset(&fl6, 0, sizeof(fl6));
986 		fl6.flowi6_proto = IPPROTO_GRE;
987 		fl6.daddr = key->u.ipv6.dst;
988 		fl6.flowlabel = key->label;
989 		fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
990 
991 		dsfield = key->tos;
992 		if (!(tun_info->key.tun_flags & TUNNEL_ERSPAN_OPT))
993 			goto tx_err;
994 		md = ip_tunnel_info_opts(tun_info);
995 		if (!md)
996 			goto tx_err;
997 
998 		tun_id = tunnel_id_to_key32(key->tun_id);
999 		if (md->version == 1) {
1000 			erspan_build_header(skb,
1001 					    ntohl(tun_id),
1002 					    ntohl(md->u.index), truncate,
1003 					    false);
1004 		} else if (md->version == 2) {
1005 			erspan_build_header_v2(skb,
1006 					       ntohl(tun_id),
1007 					       md->u.md2.dir,
1008 					       get_hwid(&md->u.md2),
1009 					       truncate, false);
1010 		} else {
1011 			goto tx_err;
1012 		}
1013 	} else {
1014 		struct ipv6hdr *ipv6h = ipv6_hdr(skb);
1015 
1016 		switch (skb->protocol) {
1017 		case htons(ETH_P_IP):
1018 			memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1019 			prepare_ip6gre_xmit_ipv4(skb, dev, &fl6,
1020 						 &dsfield, &encap_limit);
1021 			break;
1022 		case htons(ETH_P_IPV6):
1023 			if (ipv6_addr_equal(&t->parms.raddr, &ipv6h->saddr))
1024 				goto tx_err;
1025 			if (prepare_ip6gre_xmit_ipv6(skb, dev, &fl6,
1026 						     &dsfield, &encap_limit))
1027 				goto tx_err;
1028 			break;
1029 		default:
1030 			memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
1031 			break;
1032 		}
1033 
1034 		if (t->parms.erspan_ver == 1)
1035 			erspan_build_header(skb, ntohl(t->parms.o_key),
1036 					    t->parms.index,
1037 					    truncate, false);
1038 		else if (t->parms.erspan_ver == 2)
1039 			erspan_build_header_v2(skb, ntohl(t->parms.o_key),
1040 					       t->parms.dir,
1041 					       t->parms.hwid,
1042 					       truncate, false);
1043 		else
1044 			goto tx_err;
1045 
1046 		fl6.daddr = t->parms.raddr;
1047 	}
1048 
1049 	/* Push GRE header. */
1050 	gre_build_header(skb, 8, TUNNEL_SEQ,
1051 			 htons(ETH_P_ERSPAN), 0, htonl(t->o_seqno++));
1052 
1053 	/* TooBig packet may have updated dst->dev's mtu */
1054 	if (!t->parms.collect_md && dst && dst_mtu(dst) > dst->dev->mtu)
1055 		dst->ops->update_pmtu(dst, NULL, skb, dst->dev->mtu);
1056 
1057 	err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
1058 			   NEXTHDR_GRE);
1059 	if (err != 0) {
1060 		/* XXX: send ICMP error even if DF is not set. */
1061 		if (err == -EMSGSIZE) {
1062 			if (skb->protocol == htons(ETH_P_IP))
1063 				icmp_send(skb, ICMP_DEST_UNREACH,
1064 					  ICMP_FRAG_NEEDED, htonl(mtu));
1065 			else
1066 				icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
1067 		}
1068 
1069 		goto tx_err;
1070 	}
1071 	return NETDEV_TX_OK;
1072 
1073 tx_err:
1074 	stats = &t->dev->stats;
1075 	stats->tx_errors++;
1076 	stats->tx_dropped++;
1077 	kfree_skb(skb);
1078 	return NETDEV_TX_OK;
1079 }
1080 
1081 static void ip6gre_tnl_link_config_common(struct ip6_tnl *t)
1082 {
1083 	struct net_device *dev = t->dev;
1084 	struct __ip6_tnl_parm *p = &t->parms;
1085 	struct flowi6 *fl6 = &t->fl.u.ip6;
1086 
1087 	if (dev->type != ARPHRD_ETHER) {
1088 		memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
1089 		memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
1090 	}
1091 
1092 	/* Set up flowi template */
1093 	fl6->saddr = p->laddr;
1094 	fl6->daddr = p->raddr;
1095 	fl6->flowi6_oif = p->link;
1096 	fl6->flowlabel = 0;
1097 	fl6->flowi6_proto = IPPROTO_GRE;
1098 
1099 	if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
1100 		fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
1101 	if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
1102 		fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
1103 
1104 	p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
1105 	p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
1106 
1107 	if (p->flags&IP6_TNL_F_CAP_XMIT &&
1108 			p->flags&IP6_TNL_F_CAP_RCV && dev->type != ARPHRD_ETHER)
1109 		dev->flags |= IFF_POINTOPOINT;
1110 	else
1111 		dev->flags &= ~IFF_POINTOPOINT;
1112 }
1113 
1114 static void ip6gre_tnl_link_config_route(struct ip6_tnl *t, int set_mtu,
1115 					 int t_hlen)
1116 {
1117 	const struct __ip6_tnl_parm *p = &t->parms;
1118 	struct net_device *dev = t->dev;
1119 
1120 	if (p->flags & IP6_TNL_F_CAP_XMIT) {
1121 		int strict = (ipv6_addr_type(&p->raddr) &
1122 			      (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
1123 
1124 		struct rt6_info *rt = rt6_lookup(t->net,
1125 						 &p->raddr, &p->laddr,
1126 						 p->link, NULL, strict);
1127 
1128 		if (!rt)
1129 			return;
1130 
1131 		if (rt->dst.dev) {
1132 			dev->needed_headroom = rt->dst.dev->hard_header_len +
1133 					       t_hlen;
1134 
1135 			if (set_mtu) {
1136 				dev->mtu = rt->dst.dev->mtu - t_hlen;
1137 				if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1138 					dev->mtu -= 8;
1139 				if (dev->type == ARPHRD_ETHER)
1140 					dev->mtu -= ETH_HLEN;
1141 
1142 				if (dev->mtu < IPV6_MIN_MTU)
1143 					dev->mtu = IPV6_MIN_MTU;
1144 			}
1145 		}
1146 		ip6_rt_put(rt);
1147 	}
1148 }
1149 
1150 static int ip6gre_calc_hlen(struct ip6_tnl *tunnel)
1151 {
1152 	int t_hlen;
1153 
1154 	tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags);
1155 	tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen;
1156 
1157 	t_hlen = tunnel->hlen + sizeof(struct ipv6hdr);
1158 	tunnel->dev->needed_headroom = LL_MAX_HEADER + t_hlen;
1159 	return t_hlen;
1160 }
1161 
1162 static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu)
1163 {
1164 	ip6gre_tnl_link_config_common(t);
1165 	ip6gre_tnl_link_config_route(t, set_mtu, ip6gre_calc_hlen(t));
1166 }
1167 
1168 static void ip6gre_tnl_copy_tnl_parm(struct ip6_tnl *t,
1169 				     const struct __ip6_tnl_parm *p)
1170 {
1171 	t->parms.laddr = p->laddr;
1172 	t->parms.raddr = p->raddr;
1173 	t->parms.flags = p->flags;
1174 	t->parms.hop_limit = p->hop_limit;
1175 	t->parms.encap_limit = p->encap_limit;
1176 	t->parms.flowinfo = p->flowinfo;
1177 	t->parms.link = p->link;
1178 	t->parms.proto = p->proto;
1179 	t->parms.i_key = p->i_key;
1180 	t->parms.o_key = p->o_key;
1181 	t->parms.i_flags = p->i_flags;
1182 	t->parms.o_flags = p->o_flags;
1183 	t->parms.fwmark = p->fwmark;
1184 	dst_cache_reset(&t->dst_cache);
1185 }
1186 
1187 static int ip6gre_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p,
1188 			     int set_mtu)
1189 {
1190 	ip6gre_tnl_copy_tnl_parm(t, p);
1191 	ip6gre_tnl_link_config(t, set_mtu);
1192 	return 0;
1193 }
1194 
1195 static void ip6gre_tnl_parm_from_user(struct __ip6_tnl_parm *p,
1196 	const struct ip6_tnl_parm2 *u)
1197 {
1198 	p->laddr = u->laddr;
1199 	p->raddr = u->raddr;
1200 	p->flags = u->flags;
1201 	p->hop_limit = u->hop_limit;
1202 	p->encap_limit = u->encap_limit;
1203 	p->flowinfo = u->flowinfo;
1204 	p->link = u->link;
1205 	p->i_key = u->i_key;
1206 	p->o_key = u->o_key;
1207 	p->i_flags = gre_flags_to_tnl_flags(u->i_flags);
1208 	p->o_flags = gre_flags_to_tnl_flags(u->o_flags);
1209 	memcpy(p->name, u->name, sizeof(u->name));
1210 }
1211 
1212 static void ip6gre_tnl_parm_to_user(struct ip6_tnl_parm2 *u,
1213 	const struct __ip6_tnl_parm *p)
1214 {
1215 	u->proto = IPPROTO_GRE;
1216 	u->laddr = p->laddr;
1217 	u->raddr = p->raddr;
1218 	u->flags = p->flags;
1219 	u->hop_limit = p->hop_limit;
1220 	u->encap_limit = p->encap_limit;
1221 	u->flowinfo = p->flowinfo;
1222 	u->link = p->link;
1223 	u->i_key = p->i_key;
1224 	u->o_key = p->o_key;
1225 	u->i_flags = gre_tnl_flags_to_gre_flags(p->i_flags);
1226 	u->o_flags = gre_tnl_flags_to_gre_flags(p->o_flags);
1227 	memcpy(u->name, p->name, sizeof(u->name));
1228 }
1229 
1230 static int ip6gre_tunnel_ioctl(struct net_device *dev,
1231 	struct ifreq *ifr, int cmd)
1232 {
1233 	int err = 0;
1234 	struct ip6_tnl_parm2 p;
1235 	struct __ip6_tnl_parm p1;
1236 	struct ip6_tnl *t = netdev_priv(dev);
1237 	struct net *net = t->net;
1238 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1239 
1240 	memset(&p1, 0, sizeof(p1));
1241 
1242 	switch (cmd) {
1243 	case SIOCGETTUNNEL:
1244 		if (dev == ign->fb_tunnel_dev) {
1245 			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1246 				err = -EFAULT;
1247 				break;
1248 			}
1249 			ip6gre_tnl_parm_from_user(&p1, &p);
1250 			t = ip6gre_tunnel_locate(net, &p1, 0);
1251 			if (!t)
1252 				t = netdev_priv(dev);
1253 		}
1254 		memset(&p, 0, sizeof(p));
1255 		ip6gre_tnl_parm_to_user(&p, &t->parms);
1256 		if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1257 			err = -EFAULT;
1258 		break;
1259 
1260 	case SIOCADDTUNNEL:
1261 	case SIOCCHGTUNNEL:
1262 		err = -EPERM;
1263 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1264 			goto done;
1265 
1266 		err = -EFAULT;
1267 		if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1268 			goto done;
1269 
1270 		err = -EINVAL;
1271 		if ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING))
1272 			goto done;
1273 
1274 		if (!(p.i_flags&GRE_KEY))
1275 			p.i_key = 0;
1276 		if (!(p.o_flags&GRE_KEY))
1277 			p.o_key = 0;
1278 
1279 		ip6gre_tnl_parm_from_user(&p1, &p);
1280 		t = ip6gre_tunnel_locate(net, &p1, cmd == SIOCADDTUNNEL);
1281 
1282 		if (dev != ign->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
1283 			if (t) {
1284 				if (t->dev != dev) {
1285 					err = -EEXIST;
1286 					break;
1287 				}
1288 			} else {
1289 				t = netdev_priv(dev);
1290 
1291 				ip6gre_tunnel_unlink(ign, t);
1292 				synchronize_net();
1293 				ip6gre_tnl_change(t, &p1, 1);
1294 				ip6gre_tunnel_link(ign, t);
1295 				netdev_state_change(dev);
1296 			}
1297 		}
1298 
1299 		if (t) {
1300 			err = 0;
1301 
1302 			memset(&p, 0, sizeof(p));
1303 			ip6gre_tnl_parm_to_user(&p, &t->parms);
1304 			if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1305 				err = -EFAULT;
1306 		} else
1307 			err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1308 		break;
1309 
1310 	case SIOCDELTUNNEL:
1311 		err = -EPERM;
1312 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1313 			goto done;
1314 
1315 		if (dev == ign->fb_tunnel_dev) {
1316 			err = -EFAULT;
1317 			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1318 				goto done;
1319 			err = -ENOENT;
1320 			ip6gre_tnl_parm_from_user(&p1, &p);
1321 			t = ip6gre_tunnel_locate(net, &p1, 0);
1322 			if (!t)
1323 				goto done;
1324 			err = -EPERM;
1325 			if (t == netdev_priv(ign->fb_tunnel_dev))
1326 				goto done;
1327 			dev = t->dev;
1328 		}
1329 		unregister_netdevice(dev);
1330 		err = 0;
1331 		break;
1332 
1333 	default:
1334 		err = -EINVAL;
1335 	}
1336 
1337 done:
1338 	return err;
1339 }
1340 
1341 static int ip6gre_header(struct sk_buff *skb, struct net_device *dev,
1342 			 unsigned short type, const void *daddr,
1343 			 const void *saddr, unsigned int len)
1344 {
1345 	struct ip6_tnl *t = netdev_priv(dev);
1346 	struct ipv6hdr *ipv6h;
1347 	__be16 *p;
1348 
1349 	ipv6h = skb_push(skb, t->hlen + sizeof(*ipv6h));
1350 	ip6_flow_hdr(ipv6h, 0, ip6_make_flowlabel(dev_net(dev), skb,
1351 						  t->fl.u.ip6.flowlabel,
1352 						  true, &t->fl.u.ip6));
1353 	ipv6h->hop_limit = t->parms.hop_limit;
1354 	ipv6h->nexthdr = NEXTHDR_GRE;
1355 	ipv6h->saddr = t->parms.laddr;
1356 	ipv6h->daddr = t->parms.raddr;
1357 
1358 	p = (__be16 *)(ipv6h + 1);
1359 	p[0] = t->parms.o_flags;
1360 	p[1] = htons(type);
1361 
1362 	/*
1363 	 *	Set the source hardware address.
1364 	 */
1365 
1366 	if (saddr)
1367 		memcpy(&ipv6h->saddr, saddr, sizeof(struct in6_addr));
1368 	if (daddr)
1369 		memcpy(&ipv6h->daddr, daddr, sizeof(struct in6_addr));
1370 	if (!ipv6_addr_any(&ipv6h->daddr))
1371 		return t->hlen;
1372 
1373 	return -t->hlen;
1374 }
1375 
1376 static const struct header_ops ip6gre_header_ops = {
1377 	.create	= ip6gre_header,
1378 };
1379 
1380 static const struct net_device_ops ip6gre_netdev_ops = {
1381 	.ndo_init		= ip6gre_tunnel_init,
1382 	.ndo_uninit		= ip6gre_tunnel_uninit,
1383 	.ndo_start_xmit		= ip6gre_tunnel_xmit,
1384 	.ndo_do_ioctl		= ip6gre_tunnel_ioctl,
1385 	.ndo_change_mtu		= ip6_tnl_change_mtu,
1386 	.ndo_get_stats64	= ip_tunnel_get_stats64,
1387 	.ndo_get_iflink		= ip6_tnl_get_iflink,
1388 };
1389 
1390 static void ip6gre_dev_free(struct net_device *dev)
1391 {
1392 	struct ip6_tnl *t = netdev_priv(dev);
1393 
1394 	gro_cells_destroy(&t->gro_cells);
1395 	dst_cache_destroy(&t->dst_cache);
1396 	free_percpu(dev->tstats);
1397 }
1398 
1399 static void ip6gre_tunnel_setup(struct net_device *dev)
1400 {
1401 	dev->netdev_ops = &ip6gre_netdev_ops;
1402 	dev->needs_free_netdev = true;
1403 	dev->priv_destructor = ip6gre_dev_free;
1404 
1405 	dev->type = ARPHRD_IP6GRE;
1406 
1407 	dev->flags |= IFF_NOARP;
1408 	dev->addr_len = sizeof(struct in6_addr);
1409 	netif_keep_dst(dev);
1410 	/* This perm addr will be used as interface identifier by IPv6 */
1411 	dev->addr_assign_type = NET_ADDR_RANDOM;
1412 	eth_random_addr(dev->perm_addr);
1413 }
1414 
1415 #define GRE6_FEATURES (NETIF_F_SG |		\
1416 		       NETIF_F_FRAGLIST |	\
1417 		       NETIF_F_HIGHDMA |	\
1418 		       NETIF_F_HW_CSUM)
1419 
1420 static void ip6gre_tnl_init_features(struct net_device *dev)
1421 {
1422 	struct ip6_tnl *nt = netdev_priv(dev);
1423 
1424 	dev->features		|= GRE6_FEATURES;
1425 	dev->hw_features	|= GRE6_FEATURES;
1426 
1427 	if (!(nt->parms.o_flags & TUNNEL_SEQ)) {
1428 		/* TCP offload with GRE SEQ is not supported, nor
1429 		 * can we support 2 levels of outer headers requiring
1430 		 * an update.
1431 		 */
1432 		if (!(nt->parms.o_flags & TUNNEL_CSUM) ||
1433 		    nt->encap.type == TUNNEL_ENCAP_NONE) {
1434 			dev->features    |= NETIF_F_GSO_SOFTWARE;
1435 			dev->hw_features |= NETIF_F_GSO_SOFTWARE;
1436 		}
1437 
1438 		/* Can use a lockless transmit, unless we generate
1439 		 * output sequences
1440 		 */
1441 		dev->features |= NETIF_F_LLTX;
1442 	}
1443 }
1444 
1445 static int ip6gre_tunnel_init_common(struct net_device *dev)
1446 {
1447 	struct ip6_tnl *tunnel;
1448 	int ret;
1449 	int t_hlen;
1450 
1451 	tunnel = netdev_priv(dev);
1452 
1453 	tunnel->dev = dev;
1454 	tunnel->net = dev_net(dev);
1455 	strcpy(tunnel->parms.name, dev->name);
1456 
1457 	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1458 	if (!dev->tstats)
1459 		return -ENOMEM;
1460 
1461 	ret = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL);
1462 	if (ret)
1463 		goto cleanup_alloc_pcpu_stats;
1464 
1465 	ret = gro_cells_init(&tunnel->gro_cells, dev);
1466 	if (ret)
1467 		goto cleanup_dst_cache_init;
1468 
1469 	t_hlen = ip6gre_calc_hlen(tunnel);
1470 	dev->mtu = ETH_DATA_LEN - t_hlen;
1471 	if (dev->type == ARPHRD_ETHER)
1472 		dev->mtu -= ETH_HLEN;
1473 	if (!(tunnel->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1474 		dev->mtu -= 8;
1475 
1476 	if (tunnel->parms.collect_md) {
1477 		dev->features |= NETIF_F_NETNS_LOCAL;
1478 		netif_keep_dst(dev);
1479 	}
1480 	ip6gre_tnl_init_features(dev);
1481 
1482 	return 0;
1483 
1484 cleanup_dst_cache_init:
1485 	dst_cache_destroy(&tunnel->dst_cache);
1486 cleanup_alloc_pcpu_stats:
1487 	free_percpu(dev->tstats);
1488 	dev->tstats = NULL;
1489 	return ret;
1490 }
1491 
1492 static int ip6gre_tunnel_init(struct net_device *dev)
1493 {
1494 	struct ip6_tnl *tunnel;
1495 	int ret;
1496 
1497 	ret = ip6gre_tunnel_init_common(dev);
1498 	if (ret)
1499 		return ret;
1500 
1501 	tunnel = netdev_priv(dev);
1502 
1503 	if (tunnel->parms.collect_md)
1504 		return 0;
1505 
1506 	memcpy(dev->dev_addr, &tunnel->parms.laddr, sizeof(struct in6_addr));
1507 	memcpy(dev->broadcast, &tunnel->parms.raddr, sizeof(struct in6_addr));
1508 
1509 	if (ipv6_addr_any(&tunnel->parms.raddr))
1510 		dev->header_ops = &ip6gre_header_ops;
1511 
1512 	return 0;
1513 }
1514 
1515 static void ip6gre_fb_tunnel_init(struct net_device *dev)
1516 {
1517 	struct ip6_tnl *tunnel = netdev_priv(dev);
1518 
1519 	tunnel->dev = dev;
1520 	tunnel->net = dev_net(dev);
1521 	strcpy(tunnel->parms.name, dev->name);
1522 
1523 	tunnel->hlen		= sizeof(struct ipv6hdr) + 4;
1524 
1525 	dev_hold(dev);
1526 }
1527 
1528 static struct inet6_protocol ip6gre_protocol __read_mostly = {
1529 	.handler     = gre_rcv,
1530 	.err_handler = ip6gre_err,
1531 	.flags       = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1532 };
1533 
1534 static void ip6gre_destroy_tunnels(struct net *net, struct list_head *head)
1535 {
1536 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1537 	struct net_device *dev, *aux;
1538 	int prio;
1539 
1540 	for_each_netdev_safe(net, dev, aux)
1541 		if (dev->rtnl_link_ops == &ip6gre_link_ops ||
1542 		    dev->rtnl_link_ops == &ip6gre_tap_ops ||
1543 		    dev->rtnl_link_ops == &ip6erspan_tap_ops)
1544 			unregister_netdevice_queue(dev, head);
1545 
1546 	for (prio = 0; prio < 4; prio++) {
1547 		int h;
1548 		for (h = 0; h < IP6_GRE_HASH_SIZE; h++) {
1549 			struct ip6_tnl *t;
1550 
1551 			t = rtnl_dereference(ign->tunnels[prio][h]);
1552 
1553 			while (t) {
1554 				/* If dev is in the same netns, it has already
1555 				 * been added to the list by the previous loop.
1556 				 */
1557 				if (!net_eq(dev_net(t->dev), net))
1558 					unregister_netdevice_queue(t->dev,
1559 								   head);
1560 				t = rtnl_dereference(t->next);
1561 			}
1562 		}
1563 	}
1564 }
1565 
1566 static int __net_init ip6gre_init_net(struct net *net)
1567 {
1568 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1569 	int err;
1570 
1571 	if (!net_has_fallback_tunnels(net))
1572 		return 0;
1573 	ign->fb_tunnel_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6gre0",
1574 					  NET_NAME_UNKNOWN,
1575 					  ip6gre_tunnel_setup);
1576 	if (!ign->fb_tunnel_dev) {
1577 		err = -ENOMEM;
1578 		goto err_alloc_dev;
1579 	}
1580 	dev_net_set(ign->fb_tunnel_dev, net);
1581 	/* FB netdevice is special: we have one, and only one per netns.
1582 	 * Allowing to move it to another netns is clearly unsafe.
1583 	 */
1584 	ign->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
1585 
1586 
1587 	ip6gre_fb_tunnel_init(ign->fb_tunnel_dev);
1588 	ign->fb_tunnel_dev->rtnl_link_ops = &ip6gre_link_ops;
1589 
1590 	err = register_netdev(ign->fb_tunnel_dev);
1591 	if (err)
1592 		goto err_reg_dev;
1593 
1594 	rcu_assign_pointer(ign->tunnels_wc[0],
1595 			   netdev_priv(ign->fb_tunnel_dev));
1596 	return 0;
1597 
1598 err_reg_dev:
1599 	free_netdev(ign->fb_tunnel_dev);
1600 err_alloc_dev:
1601 	return err;
1602 }
1603 
1604 static void __net_exit ip6gre_exit_batch_net(struct list_head *net_list)
1605 {
1606 	struct net *net;
1607 	LIST_HEAD(list);
1608 
1609 	rtnl_lock();
1610 	list_for_each_entry(net, net_list, exit_list)
1611 		ip6gre_destroy_tunnels(net, &list);
1612 	unregister_netdevice_many(&list);
1613 	rtnl_unlock();
1614 }
1615 
1616 static struct pernet_operations ip6gre_net_ops = {
1617 	.init = ip6gre_init_net,
1618 	.exit_batch = ip6gre_exit_batch_net,
1619 	.id   = &ip6gre_net_id,
1620 	.size = sizeof(struct ip6gre_net),
1621 };
1622 
1623 static int ip6gre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[],
1624 				  struct netlink_ext_ack *extack)
1625 {
1626 	__be16 flags;
1627 
1628 	if (!data)
1629 		return 0;
1630 
1631 	flags = 0;
1632 	if (data[IFLA_GRE_IFLAGS])
1633 		flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1634 	if (data[IFLA_GRE_OFLAGS])
1635 		flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1636 	if (flags & (GRE_VERSION|GRE_ROUTING))
1637 		return -EINVAL;
1638 
1639 	return 0;
1640 }
1641 
1642 static int ip6gre_tap_validate(struct nlattr *tb[], struct nlattr *data[],
1643 			       struct netlink_ext_ack *extack)
1644 {
1645 	struct in6_addr daddr;
1646 
1647 	if (tb[IFLA_ADDRESS]) {
1648 		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1649 			return -EINVAL;
1650 		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1651 			return -EADDRNOTAVAIL;
1652 	}
1653 
1654 	if (!data)
1655 		goto out;
1656 
1657 	if (data[IFLA_GRE_REMOTE]) {
1658 		daddr = nla_get_in6_addr(data[IFLA_GRE_REMOTE]);
1659 		if (ipv6_addr_any(&daddr))
1660 			return -EINVAL;
1661 	}
1662 
1663 out:
1664 	return ip6gre_tunnel_validate(tb, data, extack);
1665 }
1666 
1667 static int ip6erspan_tap_validate(struct nlattr *tb[], struct nlattr *data[],
1668 				  struct netlink_ext_ack *extack)
1669 {
1670 	__be16 flags = 0;
1671 	int ret, ver = 0;
1672 
1673 	if (!data)
1674 		return 0;
1675 
1676 	ret = ip6gre_tap_validate(tb, data, extack);
1677 	if (ret)
1678 		return ret;
1679 
1680 	/* ERSPAN should only have GRE sequence and key flag */
1681 	if (data[IFLA_GRE_OFLAGS])
1682 		flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1683 	if (data[IFLA_GRE_IFLAGS])
1684 		flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1685 	if (!data[IFLA_GRE_COLLECT_METADATA] &&
1686 	    flags != (GRE_SEQ | GRE_KEY))
1687 		return -EINVAL;
1688 
1689 	/* ERSPAN Session ID only has 10-bit. Since we reuse
1690 	 * 32-bit key field as ID, check it's range.
1691 	 */
1692 	if (data[IFLA_GRE_IKEY] &&
1693 	    (ntohl(nla_get_be32(data[IFLA_GRE_IKEY])) & ~ID_MASK))
1694 		return -EINVAL;
1695 
1696 	if (data[IFLA_GRE_OKEY] &&
1697 	    (ntohl(nla_get_be32(data[IFLA_GRE_OKEY])) & ~ID_MASK))
1698 		return -EINVAL;
1699 
1700 	if (data[IFLA_GRE_ERSPAN_VER]) {
1701 		ver = nla_get_u8(data[IFLA_GRE_ERSPAN_VER]);
1702 		if (ver != 1 && ver != 2)
1703 			return -EINVAL;
1704 	}
1705 
1706 	if (ver == 1) {
1707 		if (data[IFLA_GRE_ERSPAN_INDEX]) {
1708 			u32 index = nla_get_u32(data[IFLA_GRE_ERSPAN_INDEX]);
1709 
1710 			if (index & ~INDEX_MASK)
1711 				return -EINVAL;
1712 		}
1713 	} else if (ver == 2) {
1714 		if (data[IFLA_GRE_ERSPAN_DIR]) {
1715 			u16 dir = nla_get_u8(data[IFLA_GRE_ERSPAN_DIR]);
1716 
1717 			if (dir & ~(DIR_MASK >> DIR_OFFSET))
1718 				return -EINVAL;
1719 		}
1720 
1721 		if (data[IFLA_GRE_ERSPAN_HWID]) {
1722 			u16 hwid = nla_get_u16(data[IFLA_GRE_ERSPAN_HWID]);
1723 
1724 			if (hwid & ~(HWID_MASK >> HWID_OFFSET))
1725 				return -EINVAL;
1726 		}
1727 	}
1728 
1729 	return 0;
1730 }
1731 
1732 static void ip6gre_netlink_parms(struct nlattr *data[],
1733 				struct __ip6_tnl_parm *parms)
1734 {
1735 	memset(parms, 0, sizeof(*parms));
1736 
1737 	if (!data)
1738 		return;
1739 
1740 	if (data[IFLA_GRE_LINK])
1741 		parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
1742 
1743 	if (data[IFLA_GRE_IFLAGS])
1744 		parms->i_flags = gre_flags_to_tnl_flags(
1745 				nla_get_be16(data[IFLA_GRE_IFLAGS]));
1746 
1747 	if (data[IFLA_GRE_OFLAGS])
1748 		parms->o_flags = gre_flags_to_tnl_flags(
1749 				nla_get_be16(data[IFLA_GRE_OFLAGS]));
1750 
1751 	if (data[IFLA_GRE_IKEY])
1752 		parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
1753 
1754 	if (data[IFLA_GRE_OKEY])
1755 		parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
1756 
1757 	if (data[IFLA_GRE_LOCAL])
1758 		parms->laddr = nla_get_in6_addr(data[IFLA_GRE_LOCAL]);
1759 
1760 	if (data[IFLA_GRE_REMOTE])
1761 		parms->raddr = nla_get_in6_addr(data[IFLA_GRE_REMOTE]);
1762 
1763 	if (data[IFLA_GRE_TTL])
1764 		parms->hop_limit = nla_get_u8(data[IFLA_GRE_TTL]);
1765 
1766 	if (data[IFLA_GRE_ENCAP_LIMIT])
1767 		parms->encap_limit = nla_get_u8(data[IFLA_GRE_ENCAP_LIMIT]);
1768 
1769 	if (data[IFLA_GRE_FLOWINFO])
1770 		parms->flowinfo = nla_get_be32(data[IFLA_GRE_FLOWINFO]);
1771 
1772 	if (data[IFLA_GRE_FLAGS])
1773 		parms->flags = nla_get_u32(data[IFLA_GRE_FLAGS]);
1774 
1775 	if (data[IFLA_GRE_FWMARK])
1776 		parms->fwmark = nla_get_u32(data[IFLA_GRE_FWMARK]);
1777 
1778 	if (data[IFLA_GRE_COLLECT_METADATA])
1779 		parms->collect_md = true;
1780 
1781 	if (data[IFLA_GRE_ERSPAN_VER])
1782 		parms->erspan_ver = nla_get_u8(data[IFLA_GRE_ERSPAN_VER]);
1783 
1784 	if (parms->erspan_ver == 1) {
1785 		if (data[IFLA_GRE_ERSPAN_INDEX])
1786 			parms->index = nla_get_u32(data[IFLA_GRE_ERSPAN_INDEX]);
1787 	} else if (parms->erspan_ver == 2) {
1788 		if (data[IFLA_GRE_ERSPAN_DIR])
1789 			parms->dir = nla_get_u8(data[IFLA_GRE_ERSPAN_DIR]);
1790 		if (data[IFLA_GRE_ERSPAN_HWID])
1791 			parms->hwid = nla_get_u16(data[IFLA_GRE_ERSPAN_HWID]);
1792 	}
1793 }
1794 
1795 static int ip6gre_tap_init(struct net_device *dev)
1796 {
1797 	int ret;
1798 
1799 	ret = ip6gre_tunnel_init_common(dev);
1800 	if (ret)
1801 		return ret;
1802 
1803 	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1804 
1805 	return 0;
1806 }
1807 
1808 static const struct net_device_ops ip6gre_tap_netdev_ops = {
1809 	.ndo_init = ip6gre_tap_init,
1810 	.ndo_uninit = ip6gre_tunnel_uninit,
1811 	.ndo_start_xmit = ip6gre_tunnel_xmit,
1812 	.ndo_set_mac_address = eth_mac_addr,
1813 	.ndo_validate_addr = eth_validate_addr,
1814 	.ndo_change_mtu = ip6_tnl_change_mtu,
1815 	.ndo_get_stats64 = ip_tunnel_get_stats64,
1816 	.ndo_get_iflink = ip6_tnl_get_iflink,
1817 };
1818 
1819 static int ip6erspan_calc_hlen(struct ip6_tnl *tunnel)
1820 {
1821 	int t_hlen;
1822 
1823 	tunnel->tun_hlen = 8;
1824 	tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen +
1825 		       erspan_hdr_len(tunnel->parms.erspan_ver);
1826 
1827 	t_hlen = tunnel->hlen + sizeof(struct ipv6hdr);
1828 	tunnel->dev->needed_headroom = LL_MAX_HEADER + t_hlen;
1829 	return t_hlen;
1830 }
1831 
1832 static int ip6erspan_tap_init(struct net_device *dev)
1833 {
1834 	struct ip6_tnl *tunnel;
1835 	int t_hlen;
1836 	int ret;
1837 
1838 	tunnel = netdev_priv(dev);
1839 
1840 	tunnel->dev = dev;
1841 	tunnel->net = dev_net(dev);
1842 	strcpy(tunnel->parms.name, dev->name);
1843 
1844 	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1845 	if (!dev->tstats)
1846 		return -ENOMEM;
1847 
1848 	ret = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL);
1849 	if (ret)
1850 		goto cleanup_alloc_pcpu_stats;
1851 
1852 	ret = gro_cells_init(&tunnel->gro_cells, dev);
1853 	if (ret)
1854 		goto cleanup_dst_cache_init;
1855 
1856 	t_hlen = ip6erspan_calc_hlen(tunnel);
1857 	dev->mtu = ETH_DATA_LEN - t_hlen;
1858 	if (dev->type == ARPHRD_ETHER)
1859 		dev->mtu -= ETH_HLEN;
1860 	if (!(tunnel->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1861 		dev->mtu -= 8;
1862 
1863 	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1864 	ip6erspan_tnl_link_config(tunnel, 1);
1865 
1866 	return 0;
1867 
1868 cleanup_dst_cache_init:
1869 	dst_cache_destroy(&tunnel->dst_cache);
1870 cleanup_alloc_pcpu_stats:
1871 	free_percpu(dev->tstats);
1872 	dev->tstats = NULL;
1873 	return ret;
1874 }
1875 
1876 static const struct net_device_ops ip6erspan_netdev_ops = {
1877 	.ndo_init =		ip6erspan_tap_init,
1878 	.ndo_uninit =		ip6erspan_tunnel_uninit,
1879 	.ndo_start_xmit =	ip6erspan_tunnel_xmit,
1880 	.ndo_set_mac_address =	eth_mac_addr,
1881 	.ndo_validate_addr =	eth_validate_addr,
1882 	.ndo_change_mtu =	ip6_tnl_change_mtu,
1883 	.ndo_get_stats64 =	ip_tunnel_get_stats64,
1884 	.ndo_get_iflink =	ip6_tnl_get_iflink,
1885 };
1886 
1887 static void ip6gre_tap_setup(struct net_device *dev)
1888 {
1889 
1890 	ether_setup(dev);
1891 
1892 	dev->max_mtu = 0;
1893 	dev->netdev_ops = &ip6gre_tap_netdev_ops;
1894 	dev->needs_free_netdev = true;
1895 	dev->priv_destructor = ip6gre_dev_free;
1896 
1897 	dev->features |= NETIF_F_NETNS_LOCAL;
1898 	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1899 	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1900 	netif_keep_dst(dev);
1901 }
1902 
1903 bool is_ip6gretap_dev(const struct net_device *dev)
1904 {
1905 	return dev->netdev_ops == &ip6gre_tap_netdev_ops;
1906 }
1907 EXPORT_SYMBOL_GPL(is_ip6gretap_dev);
1908 
1909 static bool ip6gre_netlink_encap_parms(struct nlattr *data[],
1910 				       struct ip_tunnel_encap *ipencap)
1911 {
1912 	bool ret = false;
1913 
1914 	memset(ipencap, 0, sizeof(*ipencap));
1915 
1916 	if (!data)
1917 		return ret;
1918 
1919 	if (data[IFLA_GRE_ENCAP_TYPE]) {
1920 		ret = true;
1921 		ipencap->type = nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]);
1922 	}
1923 
1924 	if (data[IFLA_GRE_ENCAP_FLAGS]) {
1925 		ret = true;
1926 		ipencap->flags = nla_get_u16(data[IFLA_GRE_ENCAP_FLAGS]);
1927 	}
1928 
1929 	if (data[IFLA_GRE_ENCAP_SPORT]) {
1930 		ret = true;
1931 		ipencap->sport = nla_get_be16(data[IFLA_GRE_ENCAP_SPORT]);
1932 	}
1933 
1934 	if (data[IFLA_GRE_ENCAP_DPORT]) {
1935 		ret = true;
1936 		ipencap->dport = nla_get_be16(data[IFLA_GRE_ENCAP_DPORT]);
1937 	}
1938 
1939 	return ret;
1940 }
1941 
1942 static int ip6gre_newlink_common(struct net *src_net, struct net_device *dev,
1943 				 struct nlattr *tb[], struct nlattr *data[],
1944 				 struct netlink_ext_ack *extack)
1945 {
1946 	struct ip6_tnl *nt;
1947 	struct ip_tunnel_encap ipencap;
1948 	int err;
1949 
1950 	nt = netdev_priv(dev);
1951 
1952 	if (ip6gre_netlink_encap_parms(data, &ipencap)) {
1953 		int err = ip6_tnl_encap_setup(nt, &ipencap);
1954 
1955 		if (err < 0)
1956 			return err;
1957 	}
1958 
1959 	if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
1960 		eth_hw_addr_random(dev);
1961 
1962 	nt->dev = dev;
1963 	nt->net = dev_net(dev);
1964 
1965 	err = register_netdevice(dev);
1966 	if (err)
1967 		goto out;
1968 
1969 	if (tb[IFLA_MTU])
1970 		ip6_tnl_change_mtu(dev, nla_get_u32(tb[IFLA_MTU]));
1971 
1972 	dev_hold(dev);
1973 
1974 out:
1975 	return err;
1976 }
1977 
1978 static int ip6gre_newlink(struct net *src_net, struct net_device *dev,
1979 			  struct nlattr *tb[], struct nlattr *data[],
1980 			  struct netlink_ext_ack *extack)
1981 {
1982 	struct ip6_tnl *nt = netdev_priv(dev);
1983 	struct net *net = dev_net(dev);
1984 	struct ip6gre_net *ign;
1985 	int err;
1986 
1987 	ip6gre_netlink_parms(data, &nt->parms);
1988 	ign = net_generic(net, ip6gre_net_id);
1989 
1990 	if (nt->parms.collect_md) {
1991 		if (rtnl_dereference(ign->collect_md_tun))
1992 			return -EEXIST;
1993 	} else {
1994 		if (ip6gre_tunnel_find(net, &nt->parms, dev->type))
1995 			return -EEXIST;
1996 	}
1997 
1998 	err = ip6gre_newlink_common(src_net, dev, tb, data, extack);
1999 	if (!err) {
2000 		ip6gre_tnl_link_config(nt, !tb[IFLA_MTU]);
2001 		ip6gre_tunnel_link_md(ign, nt);
2002 		ip6gre_tunnel_link(net_generic(net, ip6gre_net_id), nt);
2003 	}
2004 	return err;
2005 }
2006 
2007 static struct ip6_tnl *
2008 ip6gre_changelink_common(struct net_device *dev, struct nlattr *tb[],
2009 			 struct nlattr *data[], struct __ip6_tnl_parm *p_p,
2010 			 struct netlink_ext_ack *extack)
2011 {
2012 	struct ip6_tnl *t, *nt = netdev_priv(dev);
2013 	struct net *net = nt->net;
2014 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
2015 	struct ip_tunnel_encap ipencap;
2016 
2017 	if (dev == ign->fb_tunnel_dev)
2018 		return ERR_PTR(-EINVAL);
2019 
2020 	if (ip6gre_netlink_encap_parms(data, &ipencap)) {
2021 		int err = ip6_tnl_encap_setup(nt, &ipencap);
2022 
2023 		if (err < 0)
2024 			return ERR_PTR(err);
2025 	}
2026 
2027 	ip6gre_netlink_parms(data, p_p);
2028 
2029 	t = ip6gre_tunnel_locate(net, p_p, 0);
2030 
2031 	if (t) {
2032 		if (t->dev != dev)
2033 			return ERR_PTR(-EEXIST);
2034 	} else {
2035 		t = nt;
2036 	}
2037 
2038 	return t;
2039 }
2040 
2041 static int ip6gre_changelink(struct net_device *dev, struct nlattr *tb[],
2042 			     struct nlattr *data[],
2043 			     struct netlink_ext_ack *extack)
2044 {
2045 	struct ip6gre_net *ign = net_generic(dev_net(dev), ip6gre_net_id);
2046 	struct __ip6_tnl_parm p;
2047 	struct ip6_tnl *t;
2048 
2049 	t = ip6gre_changelink_common(dev, tb, data, &p, extack);
2050 	if (IS_ERR(t))
2051 		return PTR_ERR(t);
2052 
2053 	ip6gre_tunnel_unlink_md(ign, t);
2054 	ip6gre_tunnel_unlink(ign, t);
2055 	ip6gre_tnl_change(t, &p, !tb[IFLA_MTU]);
2056 	ip6gre_tunnel_link_md(ign, t);
2057 	ip6gre_tunnel_link(ign, t);
2058 	return 0;
2059 }
2060 
2061 static void ip6gre_dellink(struct net_device *dev, struct list_head *head)
2062 {
2063 	struct net *net = dev_net(dev);
2064 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
2065 
2066 	if (dev != ign->fb_tunnel_dev)
2067 		unregister_netdevice_queue(dev, head);
2068 }
2069 
2070 static size_t ip6gre_get_size(const struct net_device *dev)
2071 {
2072 	return
2073 		/* IFLA_GRE_LINK */
2074 		nla_total_size(4) +
2075 		/* IFLA_GRE_IFLAGS */
2076 		nla_total_size(2) +
2077 		/* IFLA_GRE_OFLAGS */
2078 		nla_total_size(2) +
2079 		/* IFLA_GRE_IKEY */
2080 		nla_total_size(4) +
2081 		/* IFLA_GRE_OKEY */
2082 		nla_total_size(4) +
2083 		/* IFLA_GRE_LOCAL */
2084 		nla_total_size(sizeof(struct in6_addr)) +
2085 		/* IFLA_GRE_REMOTE */
2086 		nla_total_size(sizeof(struct in6_addr)) +
2087 		/* IFLA_GRE_TTL */
2088 		nla_total_size(1) +
2089 		/* IFLA_GRE_ENCAP_LIMIT */
2090 		nla_total_size(1) +
2091 		/* IFLA_GRE_FLOWINFO */
2092 		nla_total_size(4) +
2093 		/* IFLA_GRE_FLAGS */
2094 		nla_total_size(4) +
2095 		/* IFLA_GRE_ENCAP_TYPE */
2096 		nla_total_size(2) +
2097 		/* IFLA_GRE_ENCAP_FLAGS */
2098 		nla_total_size(2) +
2099 		/* IFLA_GRE_ENCAP_SPORT */
2100 		nla_total_size(2) +
2101 		/* IFLA_GRE_ENCAP_DPORT */
2102 		nla_total_size(2) +
2103 		/* IFLA_GRE_COLLECT_METADATA */
2104 		nla_total_size(0) +
2105 		/* IFLA_GRE_FWMARK */
2106 		nla_total_size(4) +
2107 		/* IFLA_GRE_ERSPAN_INDEX */
2108 		nla_total_size(4) +
2109 		0;
2110 }
2111 
2112 static int ip6gre_fill_info(struct sk_buff *skb, const struct net_device *dev)
2113 {
2114 	struct ip6_tnl *t = netdev_priv(dev);
2115 	struct __ip6_tnl_parm *p = &t->parms;
2116 
2117 	if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
2118 	    nla_put_be16(skb, IFLA_GRE_IFLAGS,
2119 			 gre_tnl_flags_to_gre_flags(p->i_flags)) ||
2120 	    nla_put_be16(skb, IFLA_GRE_OFLAGS,
2121 			 gre_tnl_flags_to_gre_flags(p->o_flags)) ||
2122 	    nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
2123 	    nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
2124 	    nla_put_in6_addr(skb, IFLA_GRE_LOCAL, &p->laddr) ||
2125 	    nla_put_in6_addr(skb, IFLA_GRE_REMOTE, &p->raddr) ||
2126 	    nla_put_u8(skb, IFLA_GRE_TTL, p->hop_limit) ||
2127 	    nla_put_u8(skb, IFLA_GRE_ENCAP_LIMIT, p->encap_limit) ||
2128 	    nla_put_be32(skb, IFLA_GRE_FLOWINFO, p->flowinfo) ||
2129 	    nla_put_u32(skb, IFLA_GRE_FLAGS, p->flags) ||
2130 	    nla_put_u32(skb, IFLA_GRE_FWMARK, p->fwmark) ||
2131 	    nla_put_u32(skb, IFLA_GRE_ERSPAN_INDEX, p->index))
2132 		goto nla_put_failure;
2133 
2134 	if (nla_put_u16(skb, IFLA_GRE_ENCAP_TYPE,
2135 			t->encap.type) ||
2136 	    nla_put_be16(skb, IFLA_GRE_ENCAP_SPORT,
2137 			 t->encap.sport) ||
2138 	    nla_put_be16(skb, IFLA_GRE_ENCAP_DPORT,
2139 			 t->encap.dport) ||
2140 	    nla_put_u16(skb, IFLA_GRE_ENCAP_FLAGS,
2141 			t->encap.flags))
2142 		goto nla_put_failure;
2143 
2144 	if (p->collect_md) {
2145 		if (nla_put_flag(skb, IFLA_GRE_COLLECT_METADATA))
2146 			goto nla_put_failure;
2147 	}
2148 
2149 	if (nla_put_u8(skb, IFLA_GRE_ERSPAN_VER, p->erspan_ver))
2150 		goto nla_put_failure;
2151 
2152 	if (p->erspan_ver == 1) {
2153 		if (nla_put_u32(skb, IFLA_GRE_ERSPAN_INDEX, p->index))
2154 			goto nla_put_failure;
2155 	} else if (p->erspan_ver == 2) {
2156 		if (nla_put_u8(skb, IFLA_GRE_ERSPAN_DIR, p->dir))
2157 			goto nla_put_failure;
2158 		if (nla_put_u16(skb, IFLA_GRE_ERSPAN_HWID, p->hwid))
2159 			goto nla_put_failure;
2160 	}
2161 
2162 	return 0;
2163 
2164 nla_put_failure:
2165 	return -EMSGSIZE;
2166 }
2167 
2168 static const struct nla_policy ip6gre_policy[IFLA_GRE_MAX + 1] = {
2169 	[IFLA_GRE_LINK]        = { .type = NLA_U32 },
2170 	[IFLA_GRE_IFLAGS]      = { .type = NLA_U16 },
2171 	[IFLA_GRE_OFLAGS]      = { .type = NLA_U16 },
2172 	[IFLA_GRE_IKEY]        = { .type = NLA_U32 },
2173 	[IFLA_GRE_OKEY]        = { .type = NLA_U32 },
2174 	[IFLA_GRE_LOCAL]       = { .len = FIELD_SIZEOF(struct ipv6hdr, saddr) },
2175 	[IFLA_GRE_REMOTE]      = { .len = FIELD_SIZEOF(struct ipv6hdr, daddr) },
2176 	[IFLA_GRE_TTL]         = { .type = NLA_U8 },
2177 	[IFLA_GRE_ENCAP_LIMIT] = { .type = NLA_U8 },
2178 	[IFLA_GRE_FLOWINFO]    = { .type = NLA_U32 },
2179 	[IFLA_GRE_FLAGS]       = { .type = NLA_U32 },
2180 	[IFLA_GRE_ENCAP_TYPE]   = { .type = NLA_U16 },
2181 	[IFLA_GRE_ENCAP_FLAGS]  = { .type = NLA_U16 },
2182 	[IFLA_GRE_ENCAP_SPORT]  = { .type = NLA_U16 },
2183 	[IFLA_GRE_ENCAP_DPORT]  = { .type = NLA_U16 },
2184 	[IFLA_GRE_COLLECT_METADATA] = { .type = NLA_FLAG },
2185 	[IFLA_GRE_FWMARK]       = { .type = NLA_U32 },
2186 	[IFLA_GRE_ERSPAN_INDEX] = { .type = NLA_U32 },
2187 	[IFLA_GRE_ERSPAN_VER]	= { .type = NLA_U8 },
2188 	[IFLA_GRE_ERSPAN_DIR]	= { .type = NLA_U8 },
2189 	[IFLA_GRE_ERSPAN_HWID]	= { .type = NLA_U16 },
2190 };
2191 
2192 static void ip6erspan_tap_setup(struct net_device *dev)
2193 {
2194 	ether_setup(dev);
2195 
2196 	dev->netdev_ops = &ip6erspan_netdev_ops;
2197 	dev->needs_free_netdev = true;
2198 	dev->priv_destructor = ip6gre_dev_free;
2199 
2200 	dev->features |= NETIF_F_NETNS_LOCAL;
2201 	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
2202 	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
2203 	netif_keep_dst(dev);
2204 }
2205 
2206 static int ip6erspan_newlink(struct net *src_net, struct net_device *dev,
2207 			     struct nlattr *tb[], struct nlattr *data[],
2208 			     struct netlink_ext_ack *extack)
2209 {
2210 	struct ip6_tnl *nt = netdev_priv(dev);
2211 	struct net *net = dev_net(dev);
2212 	struct ip6gre_net *ign;
2213 	int err;
2214 
2215 	ip6gre_netlink_parms(data, &nt->parms);
2216 	ign = net_generic(net, ip6gre_net_id);
2217 
2218 	if (nt->parms.collect_md) {
2219 		if (rtnl_dereference(ign->collect_md_tun_erspan))
2220 			return -EEXIST;
2221 	} else {
2222 		if (ip6gre_tunnel_find(net, &nt->parms, dev->type))
2223 			return -EEXIST;
2224 	}
2225 
2226 	err = ip6gre_newlink_common(src_net, dev, tb, data, extack);
2227 	if (!err) {
2228 		ip6erspan_tnl_link_config(nt, !tb[IFLA_MTU]);
2229 		ip6erspan_tunnel_link_md(ign, nt);
2230 		ip6gre_tunnel_link(net_generic(net, ip6gre_net_id), nt);
2231 	}
2232 	return err;
2233 }
2234 
2235 static void ip6erspan_tnl_link_config(struct ip6_tnl *t, int set_mtu)
2236 {
2237 	ip6gre_tnl_link_config_common(t);
2238 	ip6gre_tnl_link_config_route(t, set_mtu, ip6erspan_calc_hlen(t));
2239 }
2240 
2241 static int ip6erspan_tnl_change(struct ip6_tnl *t,
2242 				const struct __ip6_tnl_parm *p, int set_mtu)
2243 {
2244 	ip6gre_tnl_copy_tnl_parm(t, p);
2245 	ip6erspan_tnl_link_config(t, set_mtu);
2246 	return 0;
2247 }
2248 
2249 static int ip6erspan_changelink(struct net_device *dev, struct nlattr *tb[],
2250 				struct nlattr *data[],
2251 				struct netlink_ext_ack *extack)
2252 {
2253 	struct ip6gre_net *ign = net_generic(dev_net(dev), ip6gre_net_id);
2254 	struct __ip6_tnl_parm p;
2255 	struct ip6_tnl *t;
2256 
2257 	t = ip6gre_changelink_common(dev, tb, data, &p, extack);
2258 	if (IS_ERR(t))
2259 		return PTR_ERR(t);
2260 
2261 	ip6gre_tunnel_unlink_md(ign, t);
2262 	ip6gre_tunnel_unlink(ign, t);
2263 	ip6erspan_tnl_change(t, &p, !tb[IFLA_MTU]);
2264 	ip6erspan_tunnel_link_md(ign, t);
2265 	ip6gre_tunnel_link(ign, t);
2266 	return 0;
2267 }
2268 
2269 static struct rtnl_link_ops ip6gre_link_ops __read_mostly = {
2270 	.kind		= "ip6gre",
2271 	.maxtype	= IFLA_GRE_MAX,
2272 	.policy		= ip6gre_policy,
2273 	.priv_size	= sizeof(struct ip6_tnl),
2274 	.setup		= ip6gre_tunnel_setup,
2275 	.validate	= ip6gre_tunnel_validate,
2276 	.newlink	= ip6gre_newlink,
2277 	.changelink	= ip6gre_changelink,
2278 	.dellink	= ip6gre_dellink,
2279 	.get_size	= ip6gre_get_size,
2280 	.fill_info	= ip6gre_fill_info,
2281 	.get_link_net	= ip6_tnl_get_link_net,
2282 };
2283 
2284 static struct rtnl_link_ops ip6gre_tap_ops __read_mostly = {
2285 	.kind		= "ip6gretap",
2286 	.maxtype	= IFLA_GRE_MAX,
2287 	.policy		= ip6gre_policy,
2288 	.priv_size	= sizeof(struct ip6_tnl),
2289 	.setup		= ip6gre_tap_setup,
2290 	.validate	= ip6gre_tap_validate,
2291 	.newlink	= ip6gre_newlink,
2292 	.changelink	= ip6gre_changelink,
2293 	.get_size	= ip6gre_get_size,
2294 	.fill_info	= ip6gre_fill_info,
2295 	.get_link_net	= ip6_tnl_get_link_net,
2296 };
2297 
2298 static struct rtnl_link_ops ip6erspan_tap_ops __read_mostly = {
2299 	.kind		= "ip6erspan",
2300 	.maxtype	= IFLA_GRE_MAX,
2301 	.policy		= ip6gre_policy,
2302 	.priv_size	= sizeof(struct ip6_tnl),
2303 	.setup		= ip6erspan_tap_setup,
2304 	.validate	= ip6erspan_tap_validate,
2305 	.newlink	= ip6erspan_newlink,
2306 	.changelink	= ip6erspan_changelink,
2307 	.get_size	= ip6gre_get_size,
2308 	.fill_info	= ip6gre_fill_info,
2309 	.get_link_net	= ip6_tnl_get_link_net,
2310 };
2311 
2312 /*
2313  *	And now the modules code and kernel interface.
2314  */
2315 
2316 static int __init ip6gre_init(void)
2317 {
2318 	int err;
2319 
2320 	pr_info("GRE over IPv6 tunneling driver\n");
2321 
2322 	err = register_pernet_device(&ip6gre_net_ops);
2323 	if (err < 0)
2324 		return err;
2325 
2326 	err = inet6_add_protocol(&ip6gre_protocol, IPPROTO_GRE);
2327 	if (err < 0) {
2328 		pr_info("%s: can't add protocol\n", __func__);
2329 		goto add_proto_failed;
2330 	}
2331 
2332 	err = rtnl_link_register(&ip6gre_link_ops);
2333 	if (err < 0)
2334 		goto rtnl_link_failed;
2335 
2336 	err = rtnl_link_register(&ip6gre_tap_ops);
2337 	if (err < 0)
2338 		goto tap_ops_failed;
2339 
2340 	err = rtnl_link_register(&ip6erspan_tap_ops);
2341 	if (err < 0)
2342 		goto erspan_link_failed;
2343 
2344 out:
2345 	return err;
2346 
2347 erspan_link_failed:
2348 	rtnl_link_unregister(&ip6gre_tap_ops);
2349 tap_ops_failed:
2350 	rtnl_link_unregister(&ip6gre_link_ops);
2351 rtnl_link_failed:
2352 	inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
2353 add_proto_failed:
2354 	unregister_pernet_device(&ip6gre_net_ops);
2355 	goto out;
2356 }
2357 
2358 static void __exit ip6gre_fini(void)
2359 {
2360 	rtnl_link_unregister(&ip6gre_tap_ops);
2361 	rtnl_link_unregister(&ip6gre_link_ops);
2362 	rtnl_link_unregister(&ip6erspan_tap_ops);
2363 	inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
2364 	unregister_pernet_device(&ip6gre_net_ops);
2365 }
2366 
2367 module_init(ip6gre_init);
2368 module_exit(ip6gre_fini);
2369 MODULE_LICENSE("GPL");
2370 MODULE_AUTHOR("D. Kozlov (xeb@mail.ru)");
2371 MODULE_DESCRIPTION("GRE over IPv6 tunneling device");
2372 MODULE_ALIAS_RTNL_LINK("ip6gre");
2373 MODULE_ALIAS_RTNL_LINK("ip6gretap");
2374 MODULE_ALIAS_RTNL_LINK("ip6erspan");
2375 MODULE_ALIAS_NETDEV("ip6gre0");
2376