xref: /openbmc/linux/net/ipv6/ip6_gre.c (revision 2fa49589)
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 int 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 ipv6hdr *ipv6h;
431 	struct tnl_ptk_info tpi;
432 	struct ip6_tnl *t;
433 
434 	if (gre_parse_header(skb, &tpi, NULL, htons(ETH_P_IPV6),
435 			     offset) < 0)
436 		return -EINVAL;
437 
438 	ipv6h = (const struct ipv6hdr *)skb->data;
439 	t = ip6gre_tunnel_lookup(skb->dev, &ipv6h->daddr, &ipv6h->saddr,
440 				 tpi.key, tpi.proto);
441 	if (!t)
442 		return -ENOENT;
443 
444 	switch (type) {
445 		struct ipv6_tlv_tnl_enc_lim *tel;
446 		__u32 teli;
447 	case ICMPV6_DEST_UNREACH:
448 		net_dbg_ratelimited("%s: Path to destination invalid or inactive!\n",
449 				    t->parms.name);
450 		if (code != ICMPV6_PORT_UNREACH)
451 			break;
452 		return 0;
453 	case ICMPV6_TIME_EXCEED:
454 		if (code == ICMPV6_EXC_HOPLIMIT) {
455 			net_dbg_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
456 					    t->parms.name);
457 			break;
458 		}
459 		return 0;
460 	case ICMPV6_PARAMPROB:
461 		teli = 0;
462 		if (code == ICMPV6_HDR_FIELD)
463 			teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
464 
465 		if (teli && teli == be32_to_cpu(info) - 2) {
466 			tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
467 			if (tel->encap_limit == 0) {
468 				net_dbg_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
469 						    t->parms.name);
470 			}
471 		} else {
472 			net_dbg_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
473 					    t->parms.name);
474 		}
475 		return 0;
476 	case ICMPV6_PKT_TOOBIG:
477 		ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL));
478 		return 0;
479 	case NDISC_REDIRECT:
480 		ip6_redirect(skb, net, skb->dev->ifindex, 0,
481 			     sock_net_uid(net, NULL));
482 		return 0;
483 	}
484 
485 	if (time_before(jiffies, t->err_time + IP6TUNNEL_ERR_TIMEO))
486 		t->err_count++;
487 	else
488 		t->err_count = 1;
489 	t->err_time = jiffies;
490 
491 	return 0;
492 }
493 
494 static int ip6gre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi)
495 {
496 	const struct ipv6hdr *ipv6h;
497 	struct ip6_tnl *tunnel;
498 
499 	ipv6h = ipv6_hdr(skb);
500 	tunnel = ip6gre_tunnel_lookup(skb->dev,
501 				      &ipv6h->saddr, &ipv6h->daddr, tpi->key,
502 				      tpi->proto);
503 	if (tunnel) {
504 		if (tunnel->parms.collect_md) {
505 			struct metadata_dst *tun_dst;
506 			__be64 tun_id;
507 			__be16 flags;
508 
509 			flags = tpi->flags;
510 			tun_id = key32_to_tunnel_id(tpi->key);
511 
512 			tun_dst = ipv6_tun_rx_dst(skb, flags, tun_id, 0);
513 			if (!tun_dst)
514 				return PACKET_REJECT;
515 
516 			ip6_tnl_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error);
517 		} else {
518 			ip6_tnl_rcv(tunnel, skb, tpi, NULL, log_ecn_error);
519 		}
520 
521 		return PACKET_RCVD;
522 	}
523 
524 	return PACKET_REJECT;
525 }
526 
527 static int ip6erspan_rcv(struct sk_buff *skb, int gre_hdr_len,
528 			 struct tnl_ptk_info *tpi)
529 {
530 	struct erspan_base_hdr *ershdr;
531 	struct erspan_metadata *pkt_md;
532 	const struct ipv6hdr *ipv6h;
533 	struct erspan_md2 *md2;
534 	struct ip6_tnl *tunnel;
535 	u8 ver;
536 
537 	ipv6h = ipv6_hdr(skb);
538 	ershdr = (struct erspan_base_hdr *)skb->data;
539 	ver = ershdr->ver;
540 
541 	tunnel = ip6gre_tunnel_lookup(skb->dev,
542 				      &ipv6h->saddr, &ipv6h->daddr, tpi->key,
543 				      tpi->proto);
544 	if (tunnel) {
545 		int len = erspan_hdr_len(ver);
546 
547 		if (unlikely(!pskb_may_pull(skb, len)))
548 			return PACKET_REJECT;
549 
550 		ershdr = (struct erspan_base_hdr *)skb->data;
551 		pkt_md = (struct erspan_metadata *)(ershdr + 1);
552 
553 		if (__iptunnel_pull_header(skb, len,
554 					   htons(ETH_P_TEB),
555 					   false, false) < 0)
556 			return PACKET_REJECT;
557 
558 		if (tunnel->parms.collect_md) {
559 			struct metadata_dst *tun_dst;
560 			struct ip_tunnel_info *info;
561 			struct erspan_metadata *md;
562 			__be64 tun_id;
563 			__be16 flags;
564 
565 			tpi->flags |= TUNNEL_KEY;
566 			flags = tpi->flags;
567 			tun_id = key32_to_tunnel_id(tpi->key);
568 
569 			tun_dst = ipv6_tun_rx_dst(skb, flags, tun_id,
570 						  sizeof(*md));
571 			if (!tun_dst)
572 				return PACKET_REJECT;
573 
574 			info = &tun_dst->u.tun_info;
575 			md = ip_tunnel_info_opts(info);
576 			md->version = ver;
577 			md2 = &md->u.md2;
578 			memcpy(md2, pkt_md, ver == 1 ? ERSPAN_V1_MDSIZE :
579 						       ERSPAN_V2_MDSIZE);
580 			info->key.tun_flags |= TUNNEL_ERSPAN_OPT;
581 			info->options_len = sizeof(*md);
582 
583 			ip6_tnl_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error);
584 
585 		} else {
586 			ip6_tnl_rcv(tunnel, skb, tpi, NULL, log_ecn_error);
587 		}
588 
589 		return PACKET_RCVD;
590 	}
591 
592 	return PACKET_REJECT;
593 }
594 
595 static int gre_rcv(struct sk_buff *skb)
596 {
597 	struct tnl_ptk_info tpi;
598 	bool csum_err = false;
599 	int hdr_len;
600 
601 	hdr_len = gre_parse_header(skb, &tpi, &csum_err, htons(ETH_P_IPV6), 0);
602 	if (hdr_len < 0)
603 		goto drop;
604 
605 	if (iptunnel_pull_header(skb, hdr_len, tpi.proto, false))
606 		goto drop;
607 
608 	if (unlikely(tpi.proto == htons(ETH_P_ERSPAN) ||
609 		     tpi.proto == htons(ETH_P_ERSPAN2))) {
610 		if (ip6erspan_rcv(skb, hdr_len, &tpi) == PACKET_RCVD)
611 			return 0;
612 		goto out;
613 	}
614 
615 	if (ip6gre_rcv(skb, &tpi) == PACKET_RCVD)
616 		return 0;
617 
618 out:
619 	icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
620 drop:
621 	kfree_skb(skb);
622 	return 0;
623 }
624 
625 static int gre_handle_offloads(struct sk_buff *skb, bool csum)
626 {
627 	return iptunnel_handle_offloads(skb,
628 					csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE);
629 }
630 
631 static void prepare_ip6gre_xmit_ipv4(struct sk_buff *skb,
632 				     struct net_device *dev,
633 				     struct flowi6 *fl6, __u8 *dsfield,
634 				     int *encap_limit)
635 {
636 	const struct iphdr *iph = ip_hdr(skb);
637 	struct ip6_tnl *t = netdev_priv(dev);
638 
639 	if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
640 		*encap_limit = t->parms.encap_limit;
641 
642 	memcpy(fl6, &t->fl.u.ip6, sizeof(*fl6));
643 
644 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
645 		*dsfield = ipv4_get_dsfield(iph);
646 	else
647 		*dsfield = ip6_tclass(t->parms.flowinfo);
648 
649 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
650 		fl6->flowi6_mark = skb->mark;
651 	else
652 		fl6->flowi6_mark = t->parms.fwmark;
653 
654 	fl6->flowi6_uid = sock_net_uid(dev_net(dev), NULL);
655 }
656 
657 static int prepare_ip6gre_xmit_ipv6(struct sk_buff *skb,
658 				    struct net_device *dev,
659 				    struct flowi6 *fl6, __u8 *dsfield,
660 				    int *encap_limit)
661 {
662 	struct ipv6hdr *ipv6h = ipv6_hdr(skb);
663 	struct ip6_tnl *t = netdev_priv(dev);
664 	__u16 offset;
665 
666 	offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
667 	/* ip6_tnl_parse_tlv_enc_lim() might have reallocated skb->head */
668 
669 	if (offset > 0) {
670 		struct ipv6_tlv_tnl_enc_lim *tel;
671 
672 		tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset];
673 		if (tel->encap_limit == 0) {
674 			icmpv6_send(skb, ICMPV6_PARAMPROB,
675 				    ICMPV6_HDR_FIELD, offset + 2);
676 			return -1;
677 		}
678 		*encap_limit = tel->encap_limit - 1;
679 	} else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) {
680 		*encap_limit = t->parms.encap_limit;
681 	}
682 
683 	memcpy(fl6, &t->fl.u.ip6, sizeof(*fl6));
684 
685 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
686 		*dsfield = ipv6_get_dsfield(ipv6h);
687 	else
688 		*dsfield = ip6_tclass(t->parms.flowinfo);
689 
690 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
691 		fl6->flowlabel |= ip6_flowlabel(ipv6h);
692 
693 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
694 		fl6->flowi6_mark = skb->mark;
695 	else
696 		fl6->flowi6_mark = t->parms.fwmark;
697 
698 	fl6->flowi6_uid = sock_net_uid(dev_net(dev), NULL);
699 
700 	return 0;
701 }
702 
703 static netdev_tx_t __gre6_xmit(struct sk_buff *skb,
704 			       struct net_device *dev, __u8 dsfield,
705 			       struct flowi6 *fl6, int encap_limit,
706 			       __u32 *pmtu, __be16 proto)
707 {
708 	struct ip6_tnl *tunnel = netdev_priv(dev);
709 	__be16 protocol;
710 
711 	if (dev->type == ARPHRD_ETHER)
712 		IPCB(skb)->flags = 0;
713 
714 	if (dev->header_ops && dev->type == ARPHRD_IP6GRE)
715 		fl6->daddr = ((struct ipv6hdr *)skb->data)->daddr;
716 	else
717 		fl6->daddr = tunnel->parms.raddr;
718 
719 	if (skb_cow_head(skb, dev->needed_headroom ?: tunnel->hlen))
720 		return -ENOMEM;
721 
722 	/* Push GRE header. */
723 	protocol = (dev->type == ARPHRD_ETHER) ? htons(ETH_P_TEB) : proto;
724 
725 	if (tunnel->parms.collect_md) {
726 		struct ip_tunnel_info *tun_info;
727 		const struct ip_tunnel_key *key;
728 		__be16 flags;
729 
730 		tun_info = skb_tunnel_info(skb);
731 		if (unlikely(!tun_info ||
732 			     !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
733 			     ip_tunnel_info_af(tun_info) != AF_INET6))
734 			return -EINVAL;
735 
736 		key = &tun_info->key;
737 		memset(fl6, 0, sizeof(*fl6));
738 		fl6->flowi6_proto = IPPROTO_GRE;
739 		fl6->daddr = key->u.ipv6.dst;
740 		fl6->flowlabel = key->label;
741 		fl6->flowi6_uid = sock_net_uid(dev_net(dev), NULL);
742 
743 		dsfield = key->tos;
744 		flags = key->tun_flags &
745 			(TUNNEL_CSUM | TUNNEL_KEY | TUNNEL_SEQ);
746 		tunnel->tun_hlen = gre_calc_hlen(flags);
747 
748 		gre_build_header(skb, tunnel->tun_hlen,
749 				 flags, protocol,
750 				 tunnel_id_to_key32(tun_info->key.tun_id),
751 				 (flags & TUNNEL_SEQ) ? htonl(tunnel->o_seqno++)
752 						      : 0);
753 
754 	} else {
755 		if (tunnel->parms.o_flags & TUNNEL_SEQ)
756 			tunnel->o_seqno++;
757 
758 		gre_build_header(skb, tunnel->tun_hlen, tunnel->parms.o_flags,
759 				 protocol, tunnel->parms.o_key,
760 				 htonl(tunnel->o_seqno));
761 	}
762 
763 	return ip6_tnl_xmit(skb, dev, dsfield, fl6, encap_limit, pmtu,
764 			    NEXTHDR_GRE);
765 }
766 
767 static inline int ip6gre_xmit_ipv4(struct sk_buff *skb, struct net_device *dev)
768 {
769 	struct ip6_tnl *t = netdev_priv(dev);
770 	int encap_limit = -1;
771 	struct flowi6 fl6;
772 	__u8 dsfield = 0;
773 	__u32 mtu;
774 	int err;
775 
776 	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
777 
778 	if (!t->parms.collect_md)
779 		prepare_ip6gre_xmit_ipv4(skb, dev, &fl6,
780 					 &dsfield, &encap_limit);
781 
782 	err = gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM));
783 	if (err)
784 		return -1;
785 
786 	err = __gre6_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
787 			  skb->protocol);
788 	if (err != 0) {
789 		/* XXX: send ICMP error even if DF is not set. */
790 		if (err == -EMSGSIZE)
791 			icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
792 				  htonl(mtu));
793 		return -1;
794 	}
795 
796 	return 0;
797 }
798 
799 static inline int ip6gre_xmit_ipv6(struct sk_buff *skb, struct net_device *dev)
800 {
801 	struct ip6_tnl *t = netdev_priv(dev);
802 	struct ipv6hdr *ipv6h = ipv6_hdr(skb);
803 	int encap_limit = -1;
804 	struct flowi6 fl6;
805 	__u8 dsfield = 0;
806 	__u32 mtu;
807 	int err;
808 
809 	if (ipv6_addr_equal(&t->parms.raddr, &ipv6h->saddr))
810 		return -1;
811 
812 	if (!t->parms.collect_md &&
813 	    prepare_ip6gre_xmit_ipv6(skb, dev, &fl6, &dsfield, &encap_limit))
814 		return -1;
815 
816 	if (gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM)))
817 		return -1;
818 
819 	err = __gre6_xmit(skb, dev, dsfield, &fl6, encap_limit,
820 			  &mtu, skb->protocol);
821 	if (err != 0) {
822 		if (err == -EMSGSIZE)
823 			icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
824 		return -1;
825 	}
826 
827 	return 0;
828 }
829 
830 /**
831  * ip6gre_tnl_addr_conflict - compare packet addresses to tunnel's own
832  *   @t: the outgoing tunnel device
833  *   @hdr: IPv6 header from the incoming packet
834  *
835  * Description:
836  *   Avoid trivial tunneling loop by checking that tunnel exit-point
837  *   doesn't match source of incoming packet.
838  *
839  * Return:
840  *   1 if conflict,
841  *   0 else
842  **/
843 
844 static inline bool ip6gre_tnl_addr_conflict(const struct ip6_tnl *t,
845 	const struct ipv6hdr *hdr)
846 {
847 	return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
848 }
849 
850 static int ip6gre_xmit_other(struct sk_buff *skb, struct net_device *dev)
851 {
852 	struct ip6_tnl *t = netdev_priv(dev);
853 	int encap_limit = -1;
854 	struct flowi6 fl6;
855 	__u32 mtu;
856 	int err;
857 
858 	if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
859 		encap_limit = t->parms.encap_limit;
860 
861 	if (!t->parms.collect_md)
862 		memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
863 
864 	err = gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM));
865 	if (err)
866 		return err;
867 
868 	err = __gre6_xmit(skb, dev, 0, &fl6, encap_limit, &mtu, skb->protocol);
869 
870 	return err;
871 }
872 
873 static netdev_tx_t ip6gre_tunnel_xmit(struct sk_buff *skb,
874 	struct net_device *dev)
875 {
876 	struct ip6_tnl *t = netdev_priv(dev);
877 	struct net_device_stats *stats = &t->dev->stats;
878 	int ret;
879 
880 	if (!pskb_inet_may_pull(skb))
881 		goto tx_err;
882 
883 	if (!ip6_tnl_xmit_ctl(t, &t->parms.laddr, &t->parms.raddr))
884 		goto tx_err;
885 
886 	switch (skb->protocol) {
887 	case htons(ETH_P_IP):
888 		ret = ip6gre_xmit_ipv4(skb, dev);
889 		break;
890 	case htons(ETH_P_IPV6):
891 		ret = ip6gre_xmit_ipv6(skb, dev);
892 		break;
893 	default:
894 		ret = ip6gre_xmit_other(skb, dev);
895 		break;
896 	}
897 
898 	if (ret < 0)
899 		goto tx_err;
900 
901 	return NETDEV_TX_OK;
902 
903 tx_err:
904 	stats->tx_errors++;
905 	stats->tx_dropped++;
906 	kfree_skb(skb);
907 	return NETDEV_TX_OK;
908 }
909 
910 static netdev_tx_t ip6erspan_tunnel_xmit(struct sk_buff *skb,
911 					 struct net_device *dev)
912 {
913 	struct ip6_tnl *t = netdev_priv(dev);
914 	struct dst_entry *dst = skb_dst(skb);
915 	struct net_device_stats *stats;
916 	bool truncate = false;
917 	int encap_limit = -1;
918 	__u8 dsfield = false;
919 	struct flowi6 fl6;
920 	int err = -EINVAL;
921 	__be16 proto;
922 	__u32 mtu;
923 	int nhoff;
924 	int thoff;
925 
926 	if (!pskb_inet_may_pull(skb))
927 		goto tx_err;
928 
929 	if (!ip6_tnl_xmit_ctl(t, &t->parms.laddr, &t->parms.raddr))
930 		goto tx_err;
931 
932 	if (gre_handle_offloads(skb, false))
933 		goto tx_err;
934 
935 	if (skb->len > dev->mtu + dev->hard_header_len) {
936 		pskb_trim(skb, dev->mtu + dev->hard_header_len);
937 		truncate = true;
938 	}
939 
940 	nhoff = skb_network_header(skb) - skb_mac_header(skb);
941 	if (skb->protocol == htons(ETH_P_IP) &&
942 	    (ntohs(ip_hdr(skb)->tot_len) > skb->len - nhoff))
943 		truncate = true;
944 
945 	thoff = skb_transport_header(skb) - skb_mac_header(skb);
946 	if (skb->protocol == htons(ETH_P_IPV6) &&
947 	    (ntohs(ipv6_hdr(skb)->payload_len) > skb->len - thoff))
948 		truncate = true;
949 
950 	if (skb_cow_head(skb, dev->needed_headroom ?: t->hlen))
951 		goto tx_err;
952 
953 	t->parms.o_flags &= ~TUNNEL_KEY;
954 	IPCB(skb)->flags = 0;
955 
956 	/* For collect_md mode, derive fl6 from the tunnel key,
957 	 * for native mode, call prepare_ip6gre_xmit_{ipv4,ipv6}.
958 	 */
959 	if (t->parms.collect_md) {
960 		struct ip_tunnel_info *tun_info;
961 		const struct ip_tunnel_key *key;
962 		struct erspan_metadata *md;
963 		__be32 tun_id;
964 
965 		tun_info = skb_tunnel_info(skb);
966 		if (unlikely(!tun_info ||
967 			     !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
968 			     ip_tunnel_info_af(tun_info) != AF_INET6))
969 			return -EINVAL;
970 
971 		key = &tun_info->key;
972 		memset(&fl6, 0, sizeof(fl6));
973 		fl6.flowi6_proto = IPPROTO_GRE;
974 		fl6.daddr = key->u.ipv6.dst;
975 		fl6.flowlabel = key->label;
976 		fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
977 
978 		dsfield = key->tos;
979 		if (!(tun_info->key.tun_flags & TUNNEL_ERSPAN_OPT))
980 			goto tx_err;
981 		md = ip_tunnel_info_opts(tun_info);
982 		if (!md)
983 			goto tx_err;
984 
985 		tun_id = tunnel_id_to_key32(key->tun_id);
986 		if (md->version == 1) {
987 			erspan_build_header(skb,
988 					    ntohl(tun_id),
989 					    ntohl(md->u.index), truncate,
990 					    false);
991 		} else if (md->version == 2) {
992 			erspan_build_header_v2(skb,
993 					       ntohl(tun_id),
994 					       md->u.md2.dir,
995 					       get_hwid(&md->u.md2),
996 					       truncate, false);
997 		} else {
998 			goto tx_err;
999 		}
1000 	} else {
1001 		switch (skb->protocol) {
1002 		case htons(ETH_P_IP):
1003 			memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1004 			prepare_ip6gre_xmit_ipv4(skb, dev, &fl6,
1005 						 &dsfield, &encap_limit);
1006 			break;
1007 		case htons(ETH_P_IPV6):
1008 			if (ipv6_addr_equal(&t->parms.raddr, &ipv6_hdr(skb)->saddr))
1009 				goto tx_err;
1010 			if (prepare_ip6gre_xmit_ipv6(skb, dev, &fl6,
1011 						     &dsfield, &encap_limit))
1012 				goto tx_err;
1013 			break;
1014 		default:
1015 			memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
1016 			break;
1017 		}
1018 
1019 		if (t->parms.erspan_ver == 1)
1020 			erspan_build_header(skb, ntohl(t->parms.o_key),
1021 					    t->parms.index,
1022 					    truncate, false);
1023 		else if (t->parms.erspan_ver == 2)
1024 			erspan_build_header_v2(skb, ntohl(t->parms.o_key),
1025 					       t->parms.dir,
1026 					       t->parms.hwid,
1027 					       truncate, false);
1028 		else
1029 			goto tx_err;
1030 
1031 		fl6.daddr = t->parms.raddr;
1032 	}
1033 
1034 	/* Push GRE header. */
1035 	proto = (t->parms.erspan_ver == 1) ? htons(ETH_P_ERSPAN)
1036 					   : htons(ETH_P_ERSPAN2);
1037 	gre_build_header(skb, 8, TUNNEL_SEQ, proto, 0, htonl(t->o_seqno++));
1038 
1039 	/* TooBig packet may have updated dst->dev's mtu */
1040 	if (!t->parms.collect_md && dst && dst_mtu(dst) > dst->dev->mtu)
1041 		dst->ops->update_pmtu(dst, NULL, skb, dst->dev->mtu);
1042 
1043 	err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
1044 			   NEXTHDR_GRE);
1045 	if (err != 0) {
1046 		/* XXX: send ICMP error even if DF is not set. */
1047 		if (err == -EMSGSIZE) {
1048 			if (skb->protocol == htons(ETH_P_IP))
1049 				icmp_send(skb, ICMP_DEST_UNREACH,
1050 					  ICMP_FRAG_NEEDED, htonl(mtu));
1051 			else
1052 				icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
1053 		}
1054 
1055 		goto tx_err;
1056 	}
1057 	return NETDEV_TX_OK;
1058 
1059 tx_err:
1060 	stats = &t->dev->stats;
1061 	stats->tx_errors++;
1062 	stats->tx_dropped++;
1063 	kfree_skb(skb);
1064 	return NETDEV_TX_OK;
1065 }
1066 
1067 static void ip6gre_tnl_link_config_common(struct ip6_tnl *t)
1068 {
1069 	struct net_device *dev = t->dev;
1070 	struct __ip6_tnl_parm *p = &t->parms;
1071 	struct flowi6 *fl6 = &t->fl.u.ip6;
1072 
1073 	if (dev->type != ARPHRD_ETHER) {
1074 		memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
1075 		memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
1076 	}
1077 
1078 	/* Set up flowi template */
1079 	fl6->saddr = p->laddr;
1080 	fl6->daddr = p->raddr;
1081 	fl6->flowi6_oif = p->link;
1082 	fl6->flowlabel = 0;
1083 	fl6->flowi6_proto = IPPROTO_GRE;
1084 
1085 	if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
1086 		fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
1087 	if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
1088 		fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
1089 
1090 	p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
1091 	p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
1092 
1093 	if (p->flags&IP6_TNL_F_CAP_XMIT &&
1094 			p->flags&IP6_TNL_F_CAP_RCV && dev->type != ARPHRD_ETHER)
1095 		dev->flags |= IFF_POINTOPOINT;
1096 	else
1097 		dev->flags &= ~IFF_POINTOPOINT;
1098 }
1099 
1100 static void ip6gre_tnl_link_config_route(struct ip6_tnl *t, int set_mtu,
1101 					 int t_hlen)
1102 {
1103 	const struct __ip6_tnl_parm *p = &t->parms;
1104 	struct net_device *dev = t->dev;
1105 
1106 	if (p->flags & IP6_TNL_F_CAP_XMIT) {
1107 		int strict = (ipv6_addr_type(&p->raddr) &
1108 			      (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
1109 
1110 		struct rt6_info *rt = rt6_lookup(t->net,
1111 						 &p->raddr, &p->laddr,
1112 						 p->link, NULL, strict);
1113 
1114 		if (!rt)
1115 			return;
1116 
1117 		if (rt->dst.dev) {
1118 			dev->needed_headroom = rt->dst.dev->hard_header_len +
1119 					       t_hlen;
1120 
1121 			if (set_mtu) {
1122 				dev->mtu = rt->dst.dev->mtu - t_hlen;
1123 				if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1124 					dev->mtu -= 8;
1125 				if (dev->type == ARPHRD_ETHER)
1126 					dev->mtu -= ETH_HLEN;
1127 
1128 				if (dev->mtu < IPV6_MIN_MTU)
1129 					dev->mtu = IPV6_MIN_MTU;
1130 			}
1131 		}
1132 		ip6_rt_put(rt);
1133 	}
1134 }
1135 
1136 static int ip6gre_calc_hlen(struct ip6_tnl *tunnel)
1137 {
1138 	int t_hlen;
1139 
1140 	tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags);
1141 	tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen;
1142 
1143 	t_hlen = tunnel->hlen + sizeof(struct ipv6hdr);
1144 	tunnel->dev->needed_headroom = LL_MAX_HEADER + t_hlen;
1145 	return t_hlen;
1146 }
1147 
1148 static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu)
1149 {
1150 	ip6gre_tnl_link_config_common(t);
1151 	ip6gre_tnl_link_config_route(t, set_mtu, ip6gre_calc_hlen(t));
1152 }
1153 
1154 static void ip6gre_tnl_copy_tnl_parm(struct ip6_tnl *t,
1155 				     const struct __ip6_tnl_parm *p)
1156 {
1157 	t->parms.laddr = p->laddr;
1158 	t->parms.raddr = p->raddr;
1159 	t->parms.flags = p->flags;
1160 	t->parms.hop_limit = p->hop_limit;
1161 	t->parms.encap_limit = p->encap_limit;
1162 	t->parms.flowinfo = p->flowinfo;
1163 	t->parms.link = p->link;
1164 	t->parms.proto = p->proto;
1165 	t->parms.i_key = p->i_key;
1166 	t->parms.o_key = p->o_key;
1167 	t->parms.i_flags = p->i_flags;
1168 	t->parms.o_flags = p->o_flags;
1169 	t->parms.fwmark = p->fwmark;
1170 	t->parms.erspan_ver = p->erspan_ver;
1171 	t->parms.index = p->index;
1172 	t->parms.dir = p->dir;
1173 	t->parms.hwid = p->hwid;
1174 	dst_cache_reset(&t->dst_cache);
1175 }
1176 
1177 static int ip6gre_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p,
1178 			     int set_mtu)
1179 {
1180 	ip6gre_tnl_copy_tnl_parm(t, p);
1181 	ip6gre_tnl_link_config(t, set_mtu);
1182 	return 0;
1183 }
1184 
1185 static void ip6gre_tnl_parm_from_user(struct __ip6_tnl_parm *p,
1186 	const struct ip6_tnl_parm2 *u)
1187 {
1188 	p->laddr = u->laddr;
1189 	p->raddr = u->raddr;
1190 	p->flags = u->flags;
1191 	p->hop_limit = u->hop_limit;
1192 	p->encap_limit = u->encap_limit;
1193 	p->flowinfo = u->flowinfo;
1194 	p->link = u->link;
1195 	p->i_key = u->i_key;
1196 	p->o_key = u->o_key;
1197 	p->i_flags = gre_flags_to_tnl_flags(u->i_flags);
1198 	p->o_flags = gre_flags_to_tnl_flags(u->o_flags);
1199 	memcpy(p->name, u->name, sizeof(u->name));
1200 }
1201 
1202 static void ip6gre_tnl_parm_to_user(struct ip6_tnl_parm2 *u,
1203 	const struct __ip6_tnl_parm *p)
1204 {
1205 	u->proto = IPPROTO_GRE;
1206 	u->laddr = p->laddr;
1207 	u->raddr = p->raddr;
1208 	u->flags = p->flags;
1209 	u->hop_limit = p->hop_limit;
1210 	u->encap_limit = p->encap_limit;
1211 	u->flowinfo = p->flowinfo;
1212 	u->link = p->link;
1213 	u->i_key = p->i_key;
1214 	u->o_key = p->o_key;
1215 	u->i_flags = gre_tnl_flags_to_gre_flags(p->i_flags);
1216 	u->o_flags = gre_tnl_flags_to_gre_flags(p->o_flags);
1217 	memcpy(u->name, p->name, sizeof(u->name));
1218 }
1219 
1220 static int ip6gre_tunnel_ioctl(struct net_device *dev,
1221 	struct ifreq *ifr, int cmd)
1222 {
1223 	int err = 0;
1224 	struct ip6_tnl_parm2 p;
1225 	struct __ip6_tnl_parm p1;
1226 	struct ip6_tnl *t = netdev_priv(dev);
1227 	struct net *net = t->net;
1228 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1229 
1230 	memset(&p1, 0, sizeof(p1));
1231 
1232 	switch (cmd) {
1233 	case SIOCGETTUNNEL:
1234 		if (dev == ign->fb_tunnel_dev) {
1235 			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1236 				err = -EFAULT;
1237 				break;
1238 			}
1239 			ip6gre_tnl_parm_from_user(&p1, &p);
1240 			t = ip6gre_tunnel_locate(net, &p1, 0);
1241 			if (!t)
1242 				t = netdev_priv(dev);
1243 		}
1244 		memset(&p, 0, sizeof(p));
1245 		ip6gre_tnl_parm_to_user(&p, &t->parms);
1246 		if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1247 			err = -EFAULT;
1248 		break;
1249 
1250 	case SIOCADDTUNNEL:
1251 	case SIOCCHGTUNNEL:
1252 		err = -EPERM;
1253 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1254 			goto done;
1255 
1256 		err = -EFAULT;
1257 		if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1258 			goto done;
1259 
1260 		err = -EINVAL;
1261 		if ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING))
1262 			goto done;
1263 
1264 		if (!(p.i_flags&GRE_KEY))
1265 			p.i_key = 0;
1266 		if (!(p.o_flags&GRE_KEY))
1267 			p.o_key = 0;
1268 
1269 		ip6gre_tnl_parm_from_user(&p1, &p);
1270 		t = ip6gre_tunnel_locate(net, &p1, cmd == SIOCADDTUNNEL);
1271 
1272 		if (dev != ign->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
1273 			if (t) {
1274 				if (t->dev != dev) {
1275 					err = -EEXIST;
1276 					break;
1277 				}
1278 			} else {
1279 				t = netdev_priv(dev);
1280 
1281 				ip6gre_tunnel_unlink(ign, t);
1282 				synchronize_net();
1283 				ip6gre_tnl_change(t, &p1, 1);
1284 				ip6gre_tunnel_link(ign, t);
1285 				netdev_state_change(dev);
1286 			}
1287 		}
1288 
1289 		if (t) {
1290 			err = 0;
1291 
1292 			memset(&p, 0, sizeof(p));
1293 			ip6gre_tnl_parm_to_user(&p, &t->parms);
1294 			if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1295 				err = -EFAULT;
1296 		} else
1297 			err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1298 		break;
1299 
1300 	case SIOCDELTUNNEL:
1301 		err = -EPERM;
1302 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1303 			goto done;
1304 
1305 		if (dev == ign->fb_tunnel_dev) {
1306 			err = -EFAULT;
1307 			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1308 				goto done;
1309 			err = -ENOENT;
1310 			ip6gre_tnl_parm_from_user(&p1, &p);
1311 			t = ip6gre_tunnel_locate(net, &p1, 0);
1312 			if (!t)
1313 				goto done;
1314 			err = -EPERM;
1315 			if (t == netdev_priv(ign->fb_tunnel_dev))
1316 				goto done;
1317 			dev = t->dev;
1318 		}
1319 		unregister_netdevice(dev);
1320 		err = 0;
1321 		break;
1322 
1323 	default:
1324 		err = -EINVAL;
1325 	}
1326 
1327 done:
1328 	return err;
1329 }
1330 
1331 static int ip6gre_header(struct sk_buff *skb, struct net_device *dev,
1332 			 unsigned short type, const void *daddr,
1333 			 const void *saddr, unsigned int len)
1334 {
1335 	struct ip6_tnl *t = netdev_priv(dev);
1336 	struct ipv6hdr *ipv6h;
1337 	__be16 *p;
1338 
1339 	ipv6h = skb_push(skb, t->hlen + sizeof(*ipv6h));
1340 	ip6_flow_hdr(ipv6h, 0, ip6_make_flowlabel(dev_net(dev), skb,
1341 						  t->fl.u.ip6.flowlabel,
1342 						  true, &t->fl.u.ip6));
1343 	ipv6h->hop_limit = t->parms.hop_limit;
1344 	ipv6h->nexthdr = NEXTHDR_GRE;
1345 	ipv6h->saddr = t->parms.laddr;
1346 	ipv6h->daddr = t->parms.raddr;
1347 
1348 	p = (__be16 *)(ipv6h + 1);
1349 	p[0] = t->parms.o_flags;
1350 	p[1] = htons(type);
1351 
1352 	/*
1353 	 *	Set the source hardware address.
1354 	 */
1355 
1356 	if (saddr)
1357 		memcpy(&ipv6h->saddr, saddr, sizeof(struct in6_addr));
1358 	if (daddr)
1359 		memcpy(&ipv6h->daddr, daddr, sizeof(struct in6_addr));
1360 	if (!ipv6_addr_any(&ipv6h->daddr))
1361 		return t->hlen;
1362 
1363 	return -t->hlen;
1364 }
1365 
1366 static const struct header_ops ip6gre_header_ops = {
1367 	.create	= ip6gre_header,
1368 };
1369 
1370 static const struct net_device_ops ip6gre_netdev_ops = {
1371 	.ndo_init		= ip6gre_tunnel_init,
1372 	.ndo_uninit		= ip6gre_tunnel_uninit,
1373 	.ndo_start_xmit		= ip6gre_tunnel_xmit,
1374 	.ndo_do_ioctl		= ip6gre_tunnel_ioctl,
1375 	.ndo_change_mtu		= ip6_tnl_change_mtu,
1376 	.ndo_get_stats64	= ip_tunnel_get_stats64,
1377 	.ndo_get_iflink		= ip6_tnl_get_iflink,
1378 };
1379 
1380 static void ip6gre_dev_free(struct net_device *dev)
1381 {
1382 	struct ip6_tnl *t = netdev_priv(dev);
1383 
1384 	gro_cells_destroy(&t->gro_cells);
1385 	dst_cache_destroy(&t->dst_cache);
1386 	free_percpu(dev->tstats);
1387 }
1388 
1389 static void ip6gre_tunnel_setup(struct net_device *dev)
1390 {
1391 	dev->netdev_ops = &ip6gre_netdev_ops;
1392 	dev->needs_free_netdev = true;
1393 	dev->priv_destructor = ip6gre_dev_free;
1394 
1395 	dev->type = ARPHRD_IP6GRE;
1396 
1397 	dev->flags |= IFF_NOARP;
1398 	dev->addr_len = sizeof(struct in6_addr);
1399 	netif_keep_dst(dev);
1400 	/* This perm addr will be used as interface identifier by IPv6 */
1401 	dev->addr_assign_type = NET_ADDR_RANDOM;
1402 	eth_random_addr(dev->perm_addr);
1403 }
1404 
1405 #define GRE6_FEATURES (NETIF_F_SG |		\
1406 		       NETIF_F_FRAGLIST |	\
1407 		       NETIF_F_HIGHDMA |	\
1408 		       NETIF_F_HW_CSUM)
1409 
1410 static void ip6gre_tnl_init_features(struct net_device *dev)
1411 {
1412 	struct ip6_tnl *nt = netdev_priv(dev);
1413 
1414 	dev->features		|= GRE6_FEATURES;
1415 	dev->hw_features	|= GRE6_FEATURES;
1416 
1417 	if (!(nt->parms.o_flags & TUNNEL_SEQ)) {
1418 		/* TCP offload with GRE SEQ is not supported, nor
1419 		 * can we support 2 levels of outer headers requiring
1420 		 * an update.
1421 		 */
1422 		if (!(nt->parms.o_flags & TUNNEL_CSUM) ||
1423 		    nt->encap.type == TUNNEL_ENCAP_NONE) {
1424 			dev->features    |= NETIF_F_GSO_SOFTWARE;
1425 			dev->hw_features |= NETIF_F_GSO_SOFTWARE;
1426 		}
1427 
1428 		/* Can use a lockless transmit, unless we generate
1429 		 * output sequences
1430 		 */
1431 		dev->features |= NETIF_F_LLTX;
1432 	}
1433 }
1434 
1435 static int ip6gre_tunnel_init_common(struct net_device *dev)
1436 {
1437 	struct ip6_tnl *tunnel;
1438 	int ret;
1439 	int t_hlen;
1440 
1441 	tunnel = netdev_priv(dev);
1442 
1443 	tunnel->dev = dev;
1444 	tunnel->net = dev_net(dev);
1445 	strcpy(tunnel->parms.name, dev->name);
1446 
1447 	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1448 	if (!dev->tstats)
1449 		return -ENOMEM;
1450 
1451 	ret = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL);
1452 	if (ret)
1453 		goto cleanup_alloc_pcpu_stats;
1454 
1455 	ret = gro_cells_init(&tunnel->gro_cells, dev);
1456 	if (ret)
1457 		goto cleanup_dst_cache_init;
1458 
1459 	t_hlen = ip6gre_calc_hlen(tunnel);
1460 	dev->mtu = ETH_DATA_LEN - t_hlen;
1461 	if (dev->type == ARPHRD_ETHER)
1462 		dev->mtu -= ETH_HLEN;
1463 	if (!(tunnel->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1464 		dev->mtu -= 8;
1465 
1466 	if (tunnel->parms.collect_md) {
1467 		dev->features |= NETIF_F_NETNS_LOCAL;
1468 		netif_keep_dst(dev);
1469 	}
1470 	ip6gre_tnl_init_features(dev);
1471 
1472 	return 0;
1473 
1474 cleanup_dst_cache_init:
1475 	dst_cache_destroy(&tunnel->dst_cache);
1476 cleanup_alloc_pcpu_stats:
1477 	free_percpu(dev->tstats);
1478 	dev->tstats = NULL;
1479 	return ret;
1480 }
1481 
1482 static int ip6gre_tunnel_init(struct net_device *dev)
1483 {
1484 	struct ip6_tnl *tunnel;
1485 	int ret;
1486 
1487 	ret = ip6gre_tunnel_init_common(dev);
1488 	if (ret)
1489 		return ret;
1490 
1491 	tunnel = netdev_priv(dev);
1492 
1493 	if (tunnel->parms.collect_md)
1494 		return 0;
1495 
1496 	memcpy(dev->dev_addr, &tunnel->parms.laddr, sizeof(struct in6_addr));
1497 	memcpy(dev->broadcast, &tunnel->parms.raddr, sizeof(struct in6_addr));
1498 
1499 	if (ipv6_addr_any(&tunnel->parms.raddr))
1500 		dev->header_ops = &ip6gre_header_ops;
1501 
1502 	return 0;
1503 }
1504 
1505 static void ip6gre_fb_tunnel_init(struct net_device *dev)
1506 {
1507 	struct ip6_tnl *tunnel = netdev_priv(dev);
1508 
1509 	tunnel->dev = dev;
1510 	tunnel->net = dev_net(dev);
1511 	strcpy(tunnel->parms.name, dev->name);
1512 
1513 	tunnel->hlen		= sizeof(struct ipv6hdr) + 4;
1514 
1515 	dev_hold(dev);
1516 }
1517 
1518 static struct inet6_protocol ip6gre_protocol __read_mostly = {
1519 	.handler     = gre_rcv,
1520 	.err_handler = ip6gre_err,
1521 	.flags       = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1522 };
1523 
1524 static void ip6gre_destroy_tunnels(struct net *net, struct list_head *head)
1525 {
1526 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1527 	struct net_device *dev, *aux;
1528 	int prio;
1529 
1530 	for_each_netdev_safe(net, dev, aux)
1531 		if (dev->rtnl_link_ops == &ip6gre_link_ops ||
1532 		    dev->rtnl_link_ops == &ip6gre_tap_ops ||
1533 		    dev->rtnl_link_ops == &ip6erspan_tap_ops)
1534 			unregister_netdevice_queue(dev, head);
1535 
1536 	for (prio = 0; prio < 4; prio++) {
1537 		int h;
1538 		for (h = 0; h < IP6_GRE_HASH_SIZE; h++) {
1539 			struct ip6_tnl *t;
1540 
1541 			t = rtnl_dereference(ign->tunnels[prio][h]);
1542 
1543 			while (t) {
1544 				/* If dev is in the same netns, it has already
1545 				 * been added to the list by the previous loop.
1546 				 */
1547 				if (!net_eq(dev_net(t->dev), net))
1548 					unregister_netdevice_queue(t->dev,
1549 								   head);
1550 				t = rtnl_dereference(t->next);
1551 			}
1552 		}
1553 	}
1554 }
1555 
1556 static int __net_init ip6gre_init_net(struct net *net)
1557 {
1558 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1559 	int err;
1560 
1561 	if (!net_has_fallback_tunnels(net))
1562 		return 0;
1563 	ign->fb_tunnel_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6gre0",
1564 					  NET_NAME_UNKNOWN,
1565 					  ip6gre_tunnel_setup);
1566 	if (!ign->fb_tunnel_dev) {
1567 		err = -ENOMEM;
1568 		goto err_alloc_dev;
1569 	}
1570 	dev_net_set(ign->fb_tunnel_dev, net);
1571 	/* FB netdevice is special: we have one, and only one per netns.
1572 	 * Allowing to move it to another netns is clearly unsafe.
1573 	 */
1574 	ign->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
1575 
1576 
1577 	ip6gre_fb_tunnel_init(ign->fb_tunnel_dev);
1578 	ign->fb_tunnel_dev->rtnl_link_ops = &ip6gre_link_ops;
1579 
1580 	err = register_netdev(ign->fb_tunnel_dev);
1581 	if (err)
1582 		goto err_reg_dev;
1583 
1584 	rcu_assign_pointer(ign->tunnels_wc[0],
1585 			   netdev_priv(ign->fb_tunnel_dev));
1586 	return 0;
1587 
1588 err_reg_dev:
1589 	free_netdev(ign->fb_tunnel_dev);
1590 err_alloc_dev:
1591 	return err;
1592 }
1593 
1594 static void __net_exit ip6gre_exit_batch_net(struct list_head *net_list)
1595 {
1596 	struct net *net;
1597 	LIST_HEAD(list);
1598 
1599 	rtnl_lock();
1600 	list_for_each_entry(net, net_list, exit_list)
1601 		ip6gre_destroy_tunnels(net, &list);
1602 	unregister_netdevice_many(&list);
1603 	rtnl_unlock();
1604 }
1605 
1606 static struct pernet_operations ip6gre_net_ops = {
1607 	.init = ip6gre_init_net,
1608 	.exit_batch = ip6gre_exit_batch_net,
1609 	.id   = &ip6gre_net_id,
1610 	.size = sizeof(struct ip6gre_net),
1611 };
1612 
1613 static int ip6gre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[],
1614 				  struct netlink_ext_ack *extack)
1615 {
1616 	__be16 flags;
1617 
1618 	if (!data)
1619 		return 0;
1620 
1621 	flags = 0;
1622 	if (data[IFLA_GRE_IFLAGS])
1623 		flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1624 	if (data[IFLA_GRE_OFLAGS])
1625 		flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1626 	if (flags & (GRE_VERSION|GRE_ROUTING))
1627 		return -EINVAL;
1628 
1629 	return 0;
1630 }
1631 
1632 static int ip6gre_tap_validate(struct nlattr *tb[], struct nlattr *data[],
1633 			       struct netlink_ext_ack *extack)
1634 {
1635 	struct in6_addr daddr;
1636 
1637 	if (tb[IFLA_ADDRESS]) {
1638 		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1639 			return -EINVAL;
1640 		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1641 			return -EADDRNOTAVAIL;
1642 	}
1643 
1644 	if (!data)
1645 		goto out;
1646 
1647 	if (data[IFLA_GRE_REMOTE]) {
1648 		daddr = nla_get_in6_addr(data[IFLA_GRE_REMOTE]);
1649 		if (ipv6_addr_any(&daddr))
1650 			return -EINVAL;
1651 	}
1652 
1653 out:
1654 	return ip6gre_tunnel_validate(tb, data, extack);
1655 }
1656 
1657 static int ip6erspan_tap_validate(struct nlattr *tb[], struct nlattr *data[],
1658 				  struct netlink_ext_ack *extack)
1659 {
1660 	__be16 flags = 0;
1661 	int ret, ver = 0;
1662 
1663 	if (!data)
1664 		return 0;
1665 
1666 	ret = ip6gre_tap_validate(tb, data, extack);
1667 	if (ret)
1668 		return ret;
1669 
1670 	/* ERSPAN should only have GRE sequence and key flag */
1671 	if (data[IFLA_GRE_OFLAGS])
1672 		flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1673 	if (data[IFLA_GRE_IFLAGS])
1674 		flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1675 	if (!data[IFLA_GRE_COLLECT_METADATA] &&
1676 	    flags != (GRE_SEQ | GRE_KEY))
1677 		return -EINVAL;
1678 
1679 	/* ERSPAN Session ID only has 10-bit. Since we reuse
1680 	 * 32-bit key field as ID, check it's range.
1681 	 */
1682 	if (data[IFLA_GRE_IKEY] &&
1683 	    (ntohl(nla_get_be32(data[IFLA_GRE_IKEY])) & ~ID_MASK))
1684 		return -EINVAL;
1685 
1686 	if (data[IFLA_GRE_OKEY] &&
1687 	    (ntohl(nla_get_be32(data[IFLA_GRE_OKEY])) & ~ID_MASK))
1688 		return -EINVAL;
1689 
1690 	if (data[IFLA_GRE_ERSPAN_VER]) {
1691 		ver = nla_get_u8(data[IFLA_GRE_ERSPAN_VER]);
1692 		if (ver != 1 && ver != 2)
1693 			return -EINVAL;
1694 	}
1695 
1696 	if (ver == 1) {
1697 		if (data[IFLA_GRE_ERSPAN_INDEX]) {
1698 			u32 index = nla_get_u32(data[IFLA_GRE_ERSPAN_INDEX]);
1699 
1700 			if (index & ~INDEX_MASK)
1701 				return -EINVAL;
1702 		}
1703 	} else if (ver == 2) {
1704 		if (data[IFLA_GRE_ERSPAN_DIR]) {
1705 			u16 dir = nla_get_u8(data[IFLA_GRE_ERSPAN_DIR]);
1706 
1707 			if (dir & ~(DIR_MASK >> DIR_OFFSET))
1708 				return -EINVAL;
1709 		}
1710 
1711 		if (data[IFLA_GRE_ERSPAN_HWID]) {
1712 			u16 hwid = nla_get_u16(data[IFLA_GRE_ERSPAN_HWID]);
1713 
1714 			if (hwid & ~(HWID_MASK >> HWID_OFFSET))
1715 				return -EINVAL;
1716 		}
1717 	}
1718 
1719 	return 0;
1720 }
1721 
1722 static void ip6gre_netlink_parms(struct nlattr *data[],
1723 				struct __ip6_tnl_parm *parms)
1724 {
1725 	memset(parms, 0, sizeof(*parms));
1726 
1727 	if (!data)
1728 		return;
1729 
1730 	if (data[IFLA_GRE_LINK])
1731 		parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
1732 
1733 	if (data[IFLA_GRE_IFLAGS])
1734 		parms->i_flags = gre_flags_to_tnl_flags(
1735 				nla_get_be16(data[IFLA_GRE_IFLAGS]));
1736 
1737 	if (data[IFLA_GRE_OFLAGS])
1738 		parms->o_flags = gre_flags_to_tnl_flags(
1739 				nla_get_be16(data[IFLA_GRE_OFLAGS]));
1740 
1741 	if (data[IFLA_GRE_IKEY])
1742 		parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
1743 
1744 	if (data[IFLA_GRE_OKEY])
1745 		parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
1746 
1747 	if (data[IFLA_GRE_LOCAL])
1748 		parms->laddr = nla_get_in6_addr(data[IFLA_GRE_LOCAL]);
1749 
1750 	if (data[IFLA_GRE_REMOTE])
1751 		parms->raddr = nla_get_in6_addr(data[IFLA_GRE_REMOTE]);
1752 
1753 	if (data[IFLA_GRE_TTL])
1754 		parms->hop_limit = nla_get_u8(data[IFLA_GRE_TTL]);
1755 
1756 	if (data[IFLA_GRE_ENCAP_LIMIT])
1757 		parms->encap_limit = nla_get_u8(data[IFLA_GRE_ENCAP_LIMIT]);
1758 
1759 	if (data[IFLA_GRE_FLOWINFO])
1760 		parms->flowinfo = nla_get_be32(data[IFLA_GRE_FLOWINFO]);
1761 
1762 	if (data[IFLA_GRE_FLAGS])
1763 		parms->flags = nla_get_u32(data[IFLA_GRE_FLAGS]);
1764 
1765 	if (data[IFLA_GRE_FWMARK])
1766 		parms->fwmark = nla_get_u32(data[IFLA_GRE_FWMARK]);
1767 
1768 	if (data[IFLA_GRE_COLLECT_METADATA])
1769 		parms->collect_md = true;
1770 
1771 	parms->erspan_ver = 1;
1772 	if (data[IFLA_GRE_ERSPAN_VER])
1773 		parms->erspan_ver = nla_get_u8(data[IFLA_GRE_ERSPAN_VER]);
1774 
1775 	if (parms->erspan_ver == 1) {
1776 		if (data[IFLA_GRE_ERSPAN_INDEX])
1777 			parms->index = nla_get_u32(data[IFLA_GRE_ERSPAN_INDEX]);
1778 	} else if (parms->erspan_ver == 2) {
1779 		if (data[IFLA_GRE_ERSPAN_DIR])
1780 			parms->dir = nla_get_u8(data[IFLA_GRE_ERSPAN_DIR]);
1781 		if (data[IFLA_GRE_ERSPAN_HWID])
1782 			parms->hwid = nla_get_u16(data[IFLA_GRE_ERSPAN_HWID]);
1783 	}
1784 }
1785 
1786 static int ip6gre_tap_init(struct net_device *dev)
1787 {
1788 	int ret;
1789 
1790 	ret = ip6gre_tunnel_init_common(dev);
1791 	if (ret)
1792 		return ret;
1793 
1794 	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1795 
1796 	return 0;
1797 }
1798 
1799 static const struct net_device_ops ip6gre_tap_netdev_ops = {
1800 	.ndo_init = ip6gre_tap_init,
1801 	.ndo_uninit = ip6gre_tunnel_uninit,
1802 	.ndo_start_xmit = ip6gre_tunnel_xmit,
1803 	.ndo_set_mac_address = eth_mac_addr,
1804 	.ndo_validate_addr = eth_validate_addr,
1805 	.ndo_change_mtu = ip6_tnl_change_mtu,
1806 	.ndo_get_stats64 = ip_tunnel_get_stats64,
1807 	.ndo_get_iflink = ip6_tnl_get_iflink,
1808 };
1809 
1810 static int ip6erspan_calc_hlen(struct ip6_tnl *tunnel)
1811 {
1812 	int t_hlen;
1813 
1814 	tunnel->tun_hlen = 8;
1815 	tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen +
1816 		       erspan_hdr_len(tunnel->parms.erspan_ver);
1817 
1818 	t_hlen = tunnel->hlen + sizeof(struct ipv6hdr);
1819 	tunnel->dev->needed_headroom = LL_MAX_HEADER + t_hlen;
1820 	return t_hlen;
1821 }
1822 
1823 static int ip6erspan_tap_init(struct net_device *dev)
1824 {
1825 	struct ip6_tnl *tunnel;
1826 	int t_hlen;
1827 	int ret;
1828 
1829 	tunnel = netdev_priv(dev);
1830 
1831 	tunnel->dev = dev;
1832 	tunnel->net = dev_net(dev);
1833 	strcpy(tunnel->parms.name, dev->name);
1834 
1835 	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1836 	if (!dev->tstats)
1837 		return -ENOMEM;
1838 
1839 	ret = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL);
1840 	if (ret)
1841 		goto cleanup_alloc_pcpu_stats;
1842 
1843 	ret = gro_cells_init(&tunnel->gro_cells, dev);
1844 	if (ret)
1845 		goto cleanup_dst_cache_init;
1846 
1847 	t_hlen = ip6erspan_calc_hlen(tunnel);
1848 	dev->mtu = ETH_DATA_LEN - t_hlen;
1849 	if (dev->type == ARPHRD_ETHER)
1850 		dev->mtu -= ETH_HLEN;
1851 	if (!(tunnel->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1852 		dev->mtu -= 8;
1853 
1854 	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1855 	ip6erspan_tnl_link_config(tunnel, 1);
1856 
1857 	return 0;
1858 
1859 cleanup_dst_cache_init:
1860 	dst_cache_destroy(&tunnel->dst_cache);
1861 cleanup_alloc_pcpu_stats:
1862 	free_percpu(dev->tstats);
1863 	dev->tstats = NULL;
1864 	return ret;
1865 }
1866 
1867 static const struct net_device_ops ip6erspan_netdev_ops = {
1868 	.ndo_init =		ip6erspan_tap_init,
1869 	.ndo_uninit =		ip6erspan_tunnel_uninit,
1870 	.ndo_start_xmit =	ip6erspan_tunnel_xmit,
1871 	.ndo_set_mac_address =	eth_mac_addr,
1872 	.ndo_validate_addr =	eth_validate_addr,
1873 	.ndo_change_mtu =	ip6_tnl_change_mtu,
1874 	.ndo_get_stats64 =	ip_tunnel_get_stats64,
1875 	.ndo_get_iflink =	ip6_tnl_get_iflink,
1876 };
1877 
1878 static void ip6gre_tap_setup(struct net_device *dev)
1879 {
1880 
1881 	ether_setup(dev);
1882 
1883 	dev->max_mtu = 0;
1884 	dev->netdev_ops = &ip6gre_tap_netdev_ops;
1885 	dev->needs_free_netdev = true;
1886 	dev->priv_destructor = ip6gre_dev_free;
1887 
1888 	dev->features |= NETIF_F_NETNS_LOCAL;
1889 	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1890 	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1891 	netif_keep_dst(dev);
1892 }
1893 
1894 static bool ip6gre_netlink_encap_parms(struct nlattr *data[],
1895 				       struct ip_tunnel_encap *ipencap)
1896 {
1897 	bool ret = false;
1898 
1899 	memset(ipencap, 0, sizeof(*ipencap));
1900 
1901 	if (!data)
1902 		return ret;
1903 
1904 	if (data[IFLA_GRE_ENCAP_TYPE]) {
1905 		ret = true;
1906 		ipencap->type = nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]);
1907 	}
1908 
1909 	if (data[IFLA_GRE_ENCAP_FLAGS]) {
1910 		ret = true;
1911 		ipencap->flags = nla_get_u16(data[IFLA_GRE_ENCAP_FLAGS]);
1912 	}
1913 
1914 	if (data[IFLA_GRE_ENCAP_SPORT]) {
1915 		ret = true;
1916 		ipencap->sport = nla_get_be16(data[IFLA_GRE_ENCAP_SPORT]);
1917 	}
1918 
1919 	if (data[IFLA_GRE_ENCAP_DPORT]) {
1920 		ret = true;
1921 		ipencap->dport = nla_get_be16(data[IFLA_GRE_ENCAP_DPORT]);
1922 	}
1923 
1924 	return ret;
1925 }
1926 
1927 static int ip6gre_newlink_common(struct net *src_net, struct net_device *dev,
1928 				 struct nlattr *tb[], struct nlattr *data[],
1929 				 struct netlink_ext_ack *extack)
1930 {
1931 	struct ip6_tnl *nt;
1932 	struct ip_tunnel_encap ipencap;
1933 	int err;
1934 
1935 	nt = netdev_priv(dev);
1936 
1937 	if (ip6gre_netlink_encap_parms(data, &ipencap)) {
1938 		int err = ip6_tnl_encap_setup(nt, &ipencap);
1939 
1940 		if (err < 0)
1941 			return err;
1942 	}
1943 
1944 	if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
1945 		eth_hw_addr_random(dev);
1946 
1947 	nt->dev = dev;
1948 	nt->net = dev_net(dev);
1949 
1950 	err = register_netdevice(dev);
1951 	if (err)
1952 		goto out;
1953 
1954 	if (tb[IFLA_MTU])
1955 		ip6_tnl_change_mtu(dev, nla_get_u32(tb[IFLA_MTU]));
1956 
1957 	dev_hold(dev);
1958 
1959 out:
1960 	return err;
1961 }
1962 
1963 static int ip6gre_newlink(struct net *src_net, struct net_device *dev,
1964 			  struct nlattr *tb[], struct nlattr *data[],
1965 			  struct netlink_ext_ack *extack)
1966 {
1967 	struct ip6_tnl *nt = netdev_priv(dev);
1968 	struct net *net = dev_net(dev);
1969 	struct ip6gre_net *ign;
1970 	int err;
1971 
1972 	ip6gre_netlink_parms(data, &nt->parms);
1973 	ign = net_generic(net, ip6gre_net_id);
1974 
1975 	if (nt->parms.collect_md) {
1976 		if (rtnl_dereference(ign->collect_md_tun))
1977 			return -EEXIST;
1978 	} else {
1979 		if (ip6gre_tunnel_find(net, &nt->parms, dev->type))
1980 			return -EEXIST;
1981 	}
1982 
1983 	err = ip6gre_newlink_common(src_net, dev, tb, data, extack);
1984 	if (!err) {
1985 		ip6gre_tnl_link_config(nt, !tb[IFLA_MTU]);
1986 		ip6gre_tunnel_link_md(ign, nt);
1987 		ip6gre_tunnel_link(net_generic(net, ip6gre_net_id), nt);
1988 	}
1989 	return err;
1990 }
1991 
1992 static struct ip6_tnl *
1993 ip6gre_changelink_common(struct net_device *dev, struct nlattr *tb[],
1994 			 struct nlattr *data[], struct __ip6_tnl_parm *p_p,
1995 			 struct netlink_ext_ack *extack)
1996 {
1997 	struct ip6_tnl *t, *nt = netdev_priv(dev);
1998 	struct net *net = nt->net;
1999 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
2000 	struct ip_tunnel_encap ipencap;
2001 
2002 	if (dev == ign->fb_tunnel_dev)
2003 		return ERR_PTR(-EINVAL);
2004 
2005 	if (ip6gre_netlink_encap_parms(data, &ipencap)) {
2006 		int err = ip6_tnl_encap_setup(nt, &ipencap);
2007 
2008 		if (err < 0)
2009 			return ERR_PTR(err);
2010 	}
2011 
2012 	ip6gre_netlink_parms(data, p_p);
2013 
2014 	t = ip6gre_tunnel_locate(net, p_p, 0);
2015 
2016 	if (t) {
2017 		if (t->dev != dev)
2018 			return ERR_PTR(-EEXIST);
2019 	} else {
2020 		t = nt;
2021 	}
2022 
2023 	return t;
2024 }
2025 
2026 static int ip6gre_changelink(struct net_device *dev, struct nlattr *tb[],
2027 			     struct nlattr *data[],
2028 			     struct netlink_ext_ack *extack)
2029 {
2030 	struct ip6_tnl *t = netdev_priv(dev);
2031 	struct ip6gre_net *ign = net_generic(t->net, ip6gre_net_id);
2032 	struct __ip6_tnl_parm p;
2033 
2034 	t = ip6gre_changelink_common(dev, tb, data, &p, extack);
2035 	if (IS_ERR(t))
2036 		return PTR_ERR(t);
2037 
2038 	ip6gre_tunnel_unlink_md(ign, t);
2039 	ip6gre_tunnel_unlink(ign, t);
2040 	ip6gre_tnl_change(t, &p, !tb[IFLA_MTU]);
2041 	ip6gre_tunnel_link_md(ign, t);
2042 	ip6gre_tunnel_link(ign, t);
2043 	return 0;
2044 }
2045 
2046 static void ip6gre_dellink(struct net_device *dev, struct list_head *head)
2047 {
2048 	struct net *net = dev_net(dev);
2049 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
2050 
2051 	if (dev != ign->fb_tunnel_dev)
2052 		unregister_netdevice_queue(dev, head);
2053 }
2054 
2055 static size_t ip6gre_get_size(const struct net_device *dev)
2056 {
2057 	return
2058 		/* IFLA_GRE_LINK */
2059 		nla_total_size(4) +
2060 		/* IFLA_GRE_IFLAGS */
2061 		nla_total_size(2) +
2062 		/* IFLA_GRE_OFLAGS */
2063 		nla_total_size(2) +
2064 		/* IFLA_GRE_IKEY */
2065 		nla_total_size(4) +
2066 		/* IFLA_GRE_OKEY */
2067 		nla_total_size(4) +
2068 		/* IFLA_GRE_LOCAL */
2069 		nla_total_size(sizeof(struct in6_addr)) +
2070 		/* IFLA_GRE_REMOTE */
2071 		nla_total_size(sizeof(struct in6_addr)) +
2072 		/* IFLA_GRE_TTL */
2073 		nla_total_size(1) +
2074 		/* IFLA_GRE_ENCAP_LIMIT */
2075 		nla_total_size(1) +
2076 		/* IFLA_GRE_FLOWINFO */
2077 		nla_total_size(4) +
2078 		/* IFLA_GRE_FLAGS */
2079 		nla_total_size(4) +
2080 		/* IFLA_GRE_ENCAP_TYPE */
2081 		nla_total_size(2) +
2082 		/* IFLA_GRE_ENCAP_FLAGS */
2083 		nla_total_size(2) +
2084 		/* IFLA_GRE_ENCAP_SPORT */
2085 		nla_total_size(2) +
2086 		/* IFLA_GRE_ENCAP_DPORT */
2087 		nla_total_size(2) +
2088 		/* IFLA_GRE_COLLECT_METADATA */
2089 		nla_total_size(0) +
2090 		/* IFLA_GRE_FWMARK */
2091 		nla_total_size(4) +
2092 		/* IFLA_GRE_ERSPAN_INDEX */
2093 		nla_total_size(4) +
2094 		0;
2095 }
2096 
2097 static int ip6gre_fill_info(struct sk_buff *skb, const struct net_device *dev)
2098 {
2099 	struct ip6_tnl *t = netdev_priv(dev);
2100 	struct __ip6_tnl_parm *p = &t->parms;
2101 
2102 	if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
2103 	    nla_put_be16(skb, IFLA_GRE_IFLAGS,
2104 			 gre_tnl_flags_to_gre_flags(p->i_flags)) ||
2105 	    nla_put_be16(skb, IFLA_GRE_OFLAGS,
2106 			 gre_tnl_flags_to_gre_flags(p->o_flags)) ||
2107 	    nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
2108 	    nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
2109 	    nla_put_in6_addr(skb, IFLA_GRE_LOCAL, &p->laddr) ||
2110 	    nla_put_in6_addr(skb, IFLA_GRE_REMOTE, &p->raddr) ||
2111 	    nla_put_u8(skb, IFLA_GRE_TTL, p->hop_limit) ||
2112 	    nla_put_u8(skb, IFLA_GRE_ENCAP_LIMIT, p->encap_limit) ||
2113 	    nla_put_be32(skb, IFLA_GRE_FLOWINFO, p->flowinfo) ||
2114 	    nla_put_u32(skb, IFLA_GRE_FLAGS, p->flags) ||
2115 	    nla_put_u32(skb, IFLA_GRE_FWMARK, p->fwmark) ||
2116 	    nla_put_u32(skb, IFLA_GRE_ERSPAN_INDEX, p->index))
2117 		goto nla_put_failure;
2118 
2119 	if (nla_put_u16(skb, IFLA_GRE_ENCAP_TYPE,
2120 			t->encap.type) ||
2121 	    nla_put_be16(skb, IFLA_GRE_ENCAP_SPORT,
2122 			 t->encap.sport) ||
2123 	    nla_put_be16(skb, IFLA_GRE_ENCAP_DPORT,
2124 			 t->encap.dport) ||
2125 	    nla_put_u16(skb, IFLA_GRE_ENCAP_FLAGS,
2126 			t->encap.flags))
2127 		goto nla_put_failure;
2128 
2129 	if (p->collect_md) {
2130 		if (nla_put_flag(skb, IFLA_GRE_COLLECT_METADATA))
2131 			goto nla_put_failure;
2132 	}
2133 
2134 	if (nla_put_u8(skb, IFLA_GRE_ERSPAN_VER, p->erspan_ver))
2135 		goto nla_put_failure;
2136 
2137 	if (p->erspan_ver == 1) {
2138 		if (nla_put_u32(skb, IFLA_GRE_ERSPAN_INDEX, p->index))
2139 			goto nla_put_failure;
2140 	} else if (p->erspan_ver == 2) {
2141 		if (nla_put_u8(skb, IFLA_GRE_ERSPAN_DIR, p->dir))
2142 			goto nla_put_failure;
2143 		if (nla_put_u16(skb, IFLA_GRE_ERSPAN_HWID, p->hwid))
2144 			goto nla_put_failure;
2145 	}
2146 
2147 	return 0;
2148 
2149 nla_put_failure:
2150 	return -EMSGSIZE;
2151 }
2152 
2153 static const struct nla_policy ip6gre_policy[IFLA_GRE_MAX + 1] = {
2154 	[IFLA_GRE_LINK]        = { .type = NLA_U32 },
2155 	[IFLA_GRE_IFLAGS]      = { .type = NLA_U16 },
2156 	[IFLA_GRE_OFLAGS]      = { .type = NLA_U16 },
2157 	[IFLA_GRE_IKEY]        = { .type = NLA_U32 },
2158 	[IFLA_GRE_OKEY]        = { .type = NLA_U32 },
2159 	[IFLA_GRE_LOCAL]       = { .len = FIELD_SIZEOF(struct ipv6hdr, saddr) },
2160 	[IFLA_GRE_REMOTE]      = { .len = FIELD_SIZEOF(struct ipv6hdr, daddr) },
2161 	[IFLA_GRE_TTL]         = { .type = NLA_U8 },
2162 	[IFLA_GRE_ENCAP_LIMIT] = { .type = NLA_U8 },
2163 	[IFLA_GRE_FLOWINFO]    = { .type = NLA_U32 },
2164 	[IFLA_GRE_FLAGS]       = { .type = NLA_U32 },
2165 	[IFLA_GRE_ENCAP_TYPE]   = { .type = NLA_U16 },
2166 	[IFLA_GRE_ENCAP_FLAGS]  = { .type = NLA_U16 },
2167 	[IFLA_GRE_ENCAP_SPORT]  = { .type = NLA_U16 },
2168 	[IFLA_GRE_ENCAP_DPORT]  = { .type = NLA_U16 },
2169 	[IFLA_GRE_COLLECT_METADATA] = { .type = NLA_FLAG },
2170 	[IFLA_GRE_FWMARK]       = { .type = NLA_U32 },
2171 	[IFLA_GRE_ERSPAN_INDEX] = { .type = NLA_U32 },
2172 	[IFLA_GRE_ERSPAN_VER]	= { .type = NLA_U8 },
2173 	[IFLA_GRE_ERSPAN_DIR]	= { .type = NLA_U8 },
2174 	[IFLA_GRE_ERSPAN_HWID]	= { .type = NLA_U16 },
2175 };
2176 
2177 static void ip6erspan_tap_setup(struct net_device *dev)
2178 {
2179 	ether_setup(dev);
2180 
2181 	dev->netdev_ops = &ip6erspan_netdev_ops;
2182 	dev->needs_free_netdev = true;
2183 	dev->priv_destructor = ip6gre_dev_free;
2184 
2185 	dev->features |= NETIF_F_NETNS_LOCAL;
2186 	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
2187 	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
2188 	netif_keep_dst(dev);
2189 }
2190 
2191 static int ip6erspan_newlink(struct net *src_net, struct net_device *dev,
2192 			     struct nlattr *tb[], struct nlattr *data[],
2193 			     struct netlink_ext_ack *extack)
2194 {
2195 	struct ip6_tnl *nt = netdev_priv(dev);
2196 	struct net *net = dev_net(dev);
2197 	struct ip6gre_net *ign;
2198 	int err;
2199 
2200 	ip6gre_netlink_parms(data, &nt->parms);
2201 	ign = net_generic(net, ip6gre_net_id);
2202 
2203 	if (nt->parms.collect_md) {
2204 		if (rtnl_dereference(ign->collect_md_tun_erspan))
2205 			return -EEXIST;
2206 	} else {
2207 		if (ip6gre_tunnel_find(net, &nt->parms, dev->type))
2208 			return -EEXIST;
2209 	}
2210 
2211 	err = ip6gre_newlink_common(src_net, dev, tb, data, extack);
2212 	if (!err) {
2213 		ip6erspan_tnl_link_config(nt, !tb[IFLA_MTU]);
2214 		ip6erspan_tunnel_link_md(ign, nt);
2215 		ip6gre_tunnel_link(net_generic(net, ip6gre_net_id), nt);
2216 	}
2217 	return err;
2218 }
2219 
2220 static void ip6erspan_tnl_link_config(struct ip6_tnl *t, int set_mtu)
2221 {
2222 	ip6gre_tnl_link_config_common(t);
2223 	ip6gre_tnl_link_config_route(t, set_mtu, ip6erspan_calc_hlen(t));
2224 }
2225 
2226 static int ip6erspan_tnl_change(struct ip6_tnl *t,
2227 				const struct __ip6_tnl_parm *p, int set_mtu)
2228 {
2229 	ip6gre_tnl_copy_tnl_parm(t, p);
2230 	ip6erspan_tnl_link_config(t, set_mtu);
2231 	return 0;
2232 }
2233 
2234 static int ip6erspan_changelink(struct net_device *dev, struct nlattr *tb[],
2235 				struct nlattr *data[],
2236 				struct netlink_ext_ack *extack)
2237 {
2238 	struct ip6gre_net *ign = net_generic(dev_net(dev), ip6gre_net_id);
2239 	struct __ip6_tnl_parm p;
2240 	struct ip6_tnl *t;
2241 
2242 	t = ip6gre_changelink_common(dev, tb, data, &p, extack);
2243 	if (IS_ERR(t))
2244 		return PTR_ERR(t);
2245 
2246 	ip6gre_tunnel_unlink_md(ign, t);
2247 	ip6gre_tunnel_unlink(ign, t);
2248 	ip6erspan_tnl_change(t, &p, !tb[IFLA_MTU]);
2249 	ip6erspan_tunnel_link_md(ign, t);
2250 	ip6gre_tunnel_link(ign, t);
2251 	return 0;
2252 }
2253 
2254 static struct rtnl_link_ops ip6gre_link_ops __read_mostly = {
2255 	.kind		= "ip6gre",
2256 	.maxtype	= IFLA_GRE_MAX,
2257 	.policy		= ip6gre_policy,
2258 	.priv_size	= sizeof(struct ip6_tnl),
2259 	.setup		= ip6gre_tunnel_setup,
2260 	.validate	= ip6gre_tunnel_validate,
2261 	.newlink	= ip6gre_newlink,
2262 	.changelink	= ip6gre_changelink,
2263 	.dellink	= ip6gre_dellink,
2264 	.get_size	= ip6gre_get_size,
2265 	.fill_info	= ip6gre_fill_info,
2266 	.get_link_net	= ip6_tnl_get_link_net,
2267 };
2268 
2269 static struct rtnl_link_ops ip6gre_tap_ops __read_mostly = {
2270 	.kind		= "ip6gretap",
2271 	.maxtype	= IFLA_GRE_MAX,
2272 	.policy		= ip6gre_policy,
2273 	.priv_size	= sizeof(struct ip6_tnl),
2274 	.setup		= ip6gre_tap_setup,
2275 	.validate	= ip6gre_tap_validate,
2276 	.newlink	= ip6gre_newlink,
2277 	.changelink	= ip6gre_changelink,
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 ip6erspan_tap_ops __read_mostly = {
2284 	.kind		= "ip6erspan",
2285 	.maxtype	= IFLA_GRE_MAX,
2286 	.policy		= ip6gre_policy,
2287 	.priv_size	= sizeof(struct ip6_tnl),
2288 	.setup		= ip6erspan_tap_setup,
2289 	.validate	= ip6erspan_tap_validate,
2290 	.newlink	= ip6erspan_newlink,
2291 	.changelink	= ip6erspan_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 /*
2298  *	And now the modules code and kernel interface.
2299  */
2300 
2301 static int __init ip6gre_init(void)
2302 {
2303 	int err;
2304 
2305 	pr_info("GRE over IPv6 tunneling driver\n");
2306 
2307 	err = register_pernet_device(&ip6gre_net_ops);
2308 	if (err < 0)
2309 		return err;
2310 
2311 	err = inet6_add_protocol(&ip6gre_protocol, IPPROTO_GRE);
2312 	if (err < 0) {
2313 		pr_info("%s: can't add protocol\n", __func__);
2314 		goto add_proto_failed;
2315 	}
2316 
2317 	err = rtnl_link_register(&ip6gre_link_ops);
2318 	if (err < 0)
2319 		goto rtnl_link_failed;
2320 
2321 	err = rtnl_link_register(&ip6gre_tap_ops);
2322 	if (err < 0)
2323 		goto tap_ops_failed;
2324 
2325 	err = rtnl_link_register(&ip6erspan_tap_ops);
2326 	if (err < 0)
2327 		goto erspan_link_failed;
2328 
2329 out:
2330 	return err;
2331 
2332 erspan_link_failed:
2333 	rtnl_link_unregister(&ip6gre_tap_ops);
2334 tap_ops_failed:
2335 	rtnl_link_unregister(&ip6gre_link_ops);
2336 rtnl_link_failed:
2337 	inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
2338 add_proto_failed:
2339 	unregister_pernet_device(&ip6gre_net_ops);
2340 	goto out;
2341 }
2342 
2343 static void __exit ip6gre_fini(void)
2344 {
2345 	rtnl_link_unregister(&ip6gre_tap_ops);
2346 	rtnl_link_unregister(&ip6gre_link_ops);
2347 	rtnl_link_unregister(&ip6erspan_tap_ops);
2348 	inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
2349 	unregister_pernet_device(&ip6gre_net_ops);
2350 }
2351 
2352 module_init(ip6gre_init);
2353 module_exit(ip6gre_fini);
2354 MODULE_LICENSE("GPL");
2355 MODULE_AUTHOR("D. Kozlov (xeb@mail.ru)");
2356 MODULE_DESCRIPTION("GRE over IPv6 tunneling device");
2357 MODULE_ALIAS_RTNL_LINK("ip6gre");
2358 MODULE_ALIAS_RTNL_LINK("ip6gretap");
2359 MODULE_ALIAS_RTNL_LINK("ip6erspan");
2360 MODULE_ALIAS_NETDEV("ip6gre0");
2361