xref: /linux/net/ipv6/ip6_gre.c (revision 56fb34d86e875dbb0d3e6a81c5d3d035db373031)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *	GRE over IPv6 protocol decoder.
4  *
5  *	Authors: Dmitry Kozlov (xeb@mail.ru)
6  */
7 
8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9 
10 #include <linux/capability.h>
11 #include <linux/module.h>
12 #include <linux/types.h>
13 #include <linux/kernel.h>
14 #include <linux/slab.h>
15 #include <linux/uaccess.h>
16 #include <linux/skbuff.h>
17 #include <linux/netdevice.h>
18 #include <linux/in.h>
19 #include <linux/tcp.h>
20 #include <linux/udp.h>
21 #include <linux/if_arp.h>
22 #include <linux/init.h>
23 #include <linux/in6.h>
24 #include <linux/inetdevice.h>
25 #include <linux/igmp.h>
26 #include <linux/netfilter_ipv4.h>
27 #include <linux/etherdevice.h>
28 #include <linux/if_ether.h>
29 #include <linux/hash.h>
30 #include <linux/if_tunnel.h>
31 #include <linux/ip6_tunnel.h>
32 
33 #include <net/sock.h>
34 #include <net/ip.h>
35 #include <net/ip_tunnels.h>
36 #include <net/icmp.h>
37 #include <net/protocol.h>
38 #include <net/addrconf.h>
39 #include <net/arp.h>
40 #include <net/checksum.h>
41 #include <net/dsfield.h>
42 #include <net/inet_ecn.h>
43 #include <net/xfrm.h>
44 #include <net/net_namespace.h>
45 #include <net/netns/generic.h>
46 #include <net/rtnetlink.h>
47 
48 #include <net/ipv6.h>
49 #include <net/ip6_fib.h>
50 #include <net/ip6_route.h>
51 #include <net/ip6_tunnel.h>
52 #include <net/gre.h>
53 #include <net/erspan.h>
54 #include <net/dst_metadata.h>
55 
56 
57 static bool log_ecn_error = true;
58 module_param(log_ecn_error, bool, 0644);
59 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
60 
61 #define IP6_GRE_HASH_SIZE_SHIFT  5
62 #define IP6_GRE_HASH_SIZE (1 << IP6_GRE_HASH_SIZE_SHIFT)
63 
64 static unsigned int ip6gre_net_id __read_mostly;
65 struct ip6gre_net {
66 	struct ip6_tnl __rcu *tunnels[4][IP6_GRE_HASH_SIZE];
67 
68 	struct ip6_tnl __rcu *collect_md_tun;
69 	struct ip6_tnl __rcu *collect_md_tun_erspan;
70 	struct net_device *fb_tunnel_dev;
71 };
72 
73 static struct rtnl_link_ops ip6gre_link_ops __read_mostly;
74 static struct rtnl_link_ops ip6gre_tap_ops __read_mostly;
75 static struct rtnl_link_ops ip6erspan_tap_ops __read_mostly;
76 static int ip6gre_tunnel_init(struct net_device *dev);
77 static void ip6gre_tunnel_setup(struct net_device *dev);
78 static void ip6gre_tunnel_link(struct ip6gre_net *ign, struct ip6_tnl *t);
79 static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu);
80 static void ip6erspan_tnl_link_config(struct ip6_tnl *t, int set_mtu);
81 
82 /* Tunnel hash table */
83 
84 /*
85    4 hash tables:
86 
87    3: (remote,local)
88    2: (remote,*)
89    1: (*,local)
90    0: (*,*)
91 
92    We require exact key match i.e. if a key is present in packet
93    it will match only tunnel with the same key; if it is not present,
94    it will match only keyless tunnel.
95 
96    All keysless packets, if not matched configured keyless tunnels
97    will match fallback tunnel.
98  */
99 
100 #define HASH_KEY(key) (((__force u32)key^((__force u32)key>>4))&(IP6_GRE_HASH_SIZE - 1))
101 static u32 HASH_ADDR(const struct in6_addr *addr)
102 {
103 	u32 hash = ipv6_addr_hash(addr);
104 
105 	return hash_32(hash, IP6_GRE_HASH_SIZE_SHIFT);
106 }
107 
108 #define tunnels_r_l	tunnels[3]
109 #define tunnels_r	tunnels[2]
110 #define tunnels_l	tunnels[1]
111 #define tunnels_wc	tunnels[0]
112 
113 /* Given src, dst and key, find appropriate for input tunnel. */
114 
115 static struct ip6_tnl *ip6gre_tunnel_lookup(struct net_device *dev,
116 		const struct in6_addr *remote, const struct in6_addr *local,
117 		__be32 key, __be16 gre_proto)
118 {
119 	struct net *net = dev_net(dev);
120 	int link = dev->ifindex;
121 	unsigned int h0 = HASH_ADDR(remote);
122 	unsigned int h1 = HASH_KEY(key);
123 	struct ip6_tnl *t, *cand = NULL;
124 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
125 	int dev_type = (gre_proto == htons(ETH_P_TEB) ||
126 			gre_proto == htons(ETH_P_ERSPAN) ||
127 			gre_proto == htons(ETH_P_ERSPAN2)) ?
128 		       ARPHRD_ETHER : ARPHRD_IP6GRE;
129 	int score, cand_score = 4;
130 
131 	for_each_ip_tunnel_rcu(t, ign->tunnels_r_l[h0 ^ h1]) {
132 		if (!ipv6_addr_equal(local, &t->parms.laddr) ||
133 		    !ipv6_addr_equal(remote, &t->parms.raddr) ||
134 		    key != t->parms.i_key ||
135 		    !(t->dev->flags & IFF_UP))
136 			continue;
137 
138 		if (t->dev->type != ARPHRD_IP6GRE &&
139 		    t->dev->type != dev_type)
140 			continue;
141 
142 		score = 0;
143 		if (t->parms.link != link)
144 			score |= 1;
145 		if (t->dev->type != dev_type)
146 			score |= 2;
147 		if (score == 0)
148 			return t;
149 
150 		if (score < cand_score) {
151 			cand = t;
152 			cand_score = score;
153 		}
154 	}
155 
156 	for_each_ip_tunnel_rcu(t, ign->tunnels_r[h0 ^ h1]) {
157 		if (!ipv6_addr_equal(remote, &t->parms.raddr) ||
158 		    key != t->parms.i_key ||
159 		    !(t->dev->flags & IFF_UP))
160 			continue;
161 
162 		if (t->dev->type != ARPHRD_IP6GRE &&
163 		    t->dev->type != dev_type)
164 			continue;
165 
166 		score = 0;
167 		if (t->parms.link != link)
168 			score |= 1;
169 		if (t->dev->type != dev_type)
170 			score |= 2;
171 		if (score == 0)
172 			return t;
173 
174 		if (score < cand_score) {
175 			cand = t;
176 			cand_score = score;
177 		}
178 	}
179 
180 	for_each_ip_tunnel_rcu(t, ign->tunnels_l[h1]) {
181 		if ((!ipv6_addr_equal(local, &t->parms.laddr) &&
182 			  (!ipv6_addr_equal(local, &t->parms.raddr) ||
183 				 !ipv6_addr_is_multicast(local))) ||
184 		    key != t->parms.i_key ||
185 		    !(t->dev->flags & IFF_UP))
186 			continue;
187 
188 		if (t->dev->type != ARPHRD_IP6GRE &&
189 		    t->dev->type != dev_type)
190 			continue;
191 
192 		score = 0;
193 		if (t->parms.link != link)
194 			score |= 1;
195 		if (t->dev->type != dev_type)
196 			score |= 2;
197 		if (score == 0)
198 			return t;
199 
200 		if (score < cand_score) {
201 			cand = t;
202 			cand_score = score;
203 		}
204 	}
205 
206 	for_each_ip_tunnel_rcu(t, ign->tunnels_wc[h1]) {
207 		if (t->parms.i_key != key ||
208 		    !(t->dev->flags & IFF_UP))
209 			continue;
210 
211 		if (t->dev->type != ARPHRD_IP6GRE &&
212 		    t->dev->type != dev_type)
213 			continue;
214 
215 		score = 0;
216 		if (t->parms.link != link)
217 			score |= 1;
218 		if (t->dev->type != dev_type)
219 			score |= 2;
220 		if (score == 0)
221 			return t;
222 
223 		if (score < cand_score) {
224 			cand = t;
225 			cand_score = score;
226 		}
227 	}
228 
229 	if (cand)
230 		return cand;
231 
232 	if (gre_proto == htons(ETH_P_ERSPAN) ||
233 	    gre_proto == htons(ETH_P_ERSPAN2))
234 		t = rcu_dereference(ign->collect_md_tun_erspan);
235 	else
236 		t = rcu_dereference(ign->collect_md_tun);
237 
238 	if (t && t->dev->flags & IFF_UP)
239 		return t;
240 
241 	dev = ign->fb_tunnel_dev;
242 	if (dev && dev->flags & IFF_UP)
243 		return netdev_priv(dev);
244 
245 	return NULL;
246 }
247 
248 static struct ip6_tnl __rcu **__ip6gre_bucket(struct ip6gre_net *ign,
249 		const struct __ip6_tnl_parm *p)
250 {
251 	const struct in6_addr *remote = &p->raddr;
252 	const struct in6_addr *local = &p->laddr;
253 	unsigned int h = HASH_KEY(p->i_key);
254 	int prio = 0;
255 
256 	if (!ipv6_addr_any(local))
257 		prio |= 1;
258 	if (!ipv6_addr_any(remote) && !ipv6_addr_is_multicast(remote)) {
259 		prio |= 2;
260 		h ^= HASH_ADDR(remote);
261 	}
262 
263 	return &ign->tunnels[prio][h];
264 }
265 
266 static void ip6gre_tunnel_link_md(struct ip6gre_net *ign, struct ip6_tnl *t)
267 {
268 	if (t->parms.collect_md)
269 		rcu_assign_pointer(ign->collect_md_tun, t);
270 }
271 
272 static void ip6erspan_tunnel_link_md(struct ip6gre_net *ign, struct ip6_tnl *t)
273 {
274 	if (t->parms.collect_md)
275 		rcu_assign_pointer(ign->collect_md_tun_erspan, t);
276 }
277 
278 static void ip6gre_tunnel_unlink_md(struct ip6gre_net *ign, struct ip6_tnl *t)
279 {
280 	if (t->parms.collect_md)
281 		rcu_assign_pointer(ign->collect_md_tun, NULL);
282 }
283 
284 static void ip6erspan_tunnel_unlink_md(struct ip6gre_net *ign,
285 				       struct ip6_tnl *t)
286 {
287 	if (t->parms.collect_md)
288 		rcu_assign_pointer(ign->collect_md_tun_erspan, NULL);
289 }
290 
291 static inline struct ip6_tnl __rcu **ip6gre_bucket(struct ip6gre_net *ign,
292 		const struct ip6_tnl *t)
293 {
294 	return __ip6gre_bucket(ign, &t->parms);
295 }
296 
297 static void ip6gre_tunnel_link(struct ip6gre_net *ign, struct ip6_tnl *t)
298 {
299 	struct ip6_tnl __rcu **tp = ip6gre_bucket(ign, t);
300 
301 	rcu_assign_pointer(t->next, rtnl_dereference(*tp));
302 	rcu_assign_pointer(*tp, t);
303 }
304 
305 static void ip6gre_tunnel_unlink(struct ip6gre_net *ign, struct ip6_tnl *t)
306 {
307 	struct ip6_tnl __rcu **tp;
308 	struct ip6_tnl *iter;
309 
310 	for (tp = ip6gre_bucket(ign, t);
311 	     (iter = rtnl_dereference(*tp)) != NULL;
312 	     tp = &iter->next) {
313 		if (t == iter) {
314 			rcu_assign_pointer(*tp, t->next);
315 			break;
316 		}
317 	}
318 }
319 
320 static struct ip6_tnl *ip6gre_tunnel_find(struct net *net,
321 					   const struct __ip6_tnl_parm *parms,
322 					   int type)
323 {
324 	const struct in6_addr *remote = &parms->raddr;
325 	const struct in6_addr *local = &parms->laddr;
326 	__be32 key = parms->i_key;
327 	int link = parms->link;
328 	struct ip6_tnl *t;
329 	struct ip6_tnl __rcu **tp;
330 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
331 
332 	for (tp = __ip6gre_bucket(ign, parms);
333 	     (t = rtnl_dereference(*tp)) != NULL;
334 	     tp = &t->next)
335 		if (ipv6_addr_equal(local, &t->parms.laddr) &&
336 		    ipv6_addr_equal(remote, &t->parms.raddr) &&
337 		    key == t->parms.i_key &&
338 		    link == t->parms.link &&
339 		    type == t->dev->type)
340 			break;
341 
342 	return t;
343 }
344 
345 static struct ip6_tnl *ip6gre_tunnel_locate(struct net *net,
346 		const struct __ip6_tnl_parm *parms, int create)
347 {
348 	struct ip6_tnl *t, *nt;
349 	struct net_device *dev;
350 	char name[IFNAMSIZ];
351 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
352 
353 	t = ip6gre_tunnel_find(net, parms, ARPHRD_IP6GRE);
354 	if (t && create)
355 		return NULL;
356 	if (t || !create)
357 		return t;
358 
359 	if (parms->name[0]) {
360 		if (!dev_valid_name(parms->name))
361 			return NULL;
362 		strlcpy(name, parms->name, IFNAMSIZ);
363 	} else {
364 		strcpy(name, "ip6gre%d");
365 	}
366 	dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
367 			   ip6gre_tunnel_setup);
368 	if (!dev)
369 		return NULL;
370 
371 	dev_net_set(dev, net);
372 
373 	nt = netdev_priv(dev);
374 	nt->parms = *parms;
375 	dev->rtnl_link_ops = &ip6gre_link_ops;
376 
377 	nt->dev = dev;
378 	nt->net = dev_net(dev);
379 
380 	if (register_netdevice(dev) < 0)
381 		goto failed_free;
382 
383 	ip6gre_tnl_link_config(nt, 1);
384 
385 	/* Can use a lockless transmit, unless we generate output sequences */
386 	if (!(nt->parms.o_flags & TUNNEL_SEQ))
387 		dev->features |= NETIF_F_LLTX;
388 
389 	dev_hold(dev);
390 	ip6gre_tunnel_link(ign, nt);
391 	return nt;
392 
393 failed_free:
394 	free_netdev(dev);
395 	return NULL;
396 }
397 
398 static void ip6erspan_tunnel_uninit(struct net_device *dev)
399 {
400 	struct ip6_tnl *t = netdev_priv(dev);
401 	struct ip6gre_net *ign = net_generic(t->net, ip6gre_net_id);
402 
403 	ip6erspan_tunnel_unlink_md(ign, t);
404 	ip6gre_tunnel_unlink(ign, t);
405 	dst_cache_reset(&t->dst_cache);
406 	dev_put(dev);
407 }
408 
409 static void ip6gre_tunnel_uninit(struct net_device *dev)
410 {
411 	struct ip6_tnl *t = netdev_priv(dev);
412 	struct ip6gre_net *ign = net_generic(t->net, ip6gre_net_id);
413 
414 	ip6gre_tunnel_unlink_md(ign, t);
415 	ip6gre_tunnel_unlink(ign, t);
416 	dst_cache_reset(&t->dst_cache);
417 	dev_put(dev);
418 }
419 
420 
421 static int ip6gre_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
422 		       u8 type, u8 code, int offset, __be32 info)
423 {
424 	struct net *net = dev_net(skb->dev);
425 	const struct ipv6hdr *ipv6h;
426 	struct tnl_ptk_info tpi;
427 	struct ip6_tnl *t;
428 
429 	if (gre_parse_header(skb, &tpi, NULL, htons(ETH_P_IPV6),
430 			     offset) < 0)
431 		return -EINVAL;
432 
433 	ipv6h = (const struct ipv6hdr *)skb->data;
434 	t = ip6gre_tunnel_lookup(skb->dev, &ipv6h->daddr, &ipv6h->saddr,
435 				 tpi.key, tpi.proto);
436 	if (!t)
437 		return -ENOENT;
438 
439 	switch (type) {
440 		struct ipv6_tlv_tnl_enc_lim *tel;
441 		__u32 teli;
442 	case ICMPV6_DEST_UNREACH:
443 		net_dbg_ratelimited("%s: Path to destination invalid or inactive!\n",
444 				    t->parms.name);
445 		if (code != ICMPV6_PORT_UNREACH)
446 			break;
447 		return 0;
448 	case ICMPV6_TIME_EXCEED:
449 		if (code == ICMPV6_EXC_HOPLIMIT) {
450 			net_dbg_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
451 					    t->parms.name);
452 			break;
453 		}
454 		return 0;
455 	case ICMPV6_PARAMPROB:
456 		teli = 0;
457 		if (code == ICMPV6_HDR_FIELD)
458 			teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
459 
460 		if (teli && teli == be32_to_cpu(info) - 2) {
461 			tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
462 			if (tel->encap_limit == 0) {
463 				net_dbg_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
464 						    t->parms.name);
465 			}
466 		} else {
467 			net_dbg_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
468 					    t->parms.name);
469 		}
470 		return 0;
471 	case ICMPV6_PKT_TOOBIG:
472 		ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL));
473 		return 0;
474 	case NDISC_REDIRECT:
475 		ip6_redirect(skb, net, skb->dev->ifindex, 0,
476 			     sock_net_uid(net, NULL));
477 		return 0;
478 	}
479 
480 	if (time_before(jiffies, t->err_time + IP6TUNNEL_ERR_TIMEO))
481 		t->err_count++;
482 	else
483 		t->err_count = 1;
484 	t->err_time = jiffies;
485 
486 	return 0;
487 }
488 
489 static int ip6gre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi)
490 {
491 	const struct ipv6hdr *ipv6h;
492 	struct ip6_tnl *tunnel;
493 
494 	ipv6h = ipv6_hdr(skb);
495 	tunnel = ip6gre_tunnel_lookup(skb->dev,
496 				      &ipv6h->saddr, &ipv6h->daddr, tpi->key,
497 				      tpi->proto);
498 	if (tunnel) {
499 		if (tunnel->parms.collect_md) {
500 			struct metadata_dst *tun_dst;
501 			__be64 tun_id;
502 			__be16 flags;
503 
504 			flags = tpi->flags;
505 			tun_id = key32_to_tunnel_id(tpi->key);
506 
507 			tun_dst = ipv6_tun_rx_dst(skb, flags, tun_id, 0);
508 			if (!tun_dst)
509 				return PACKET_REJECT;
510 
511 			ip6_tnl_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error);
512 		} else {
513 			ip6_tnl_rcv(tunnel, skb, tpi, NULL, log_ecn_error);
514 		}
515 
516 		return PACKET_RCVD;
517 	}
518 
519 	return PACKET_REJECT;
520 }
521 
522 static int ip6erspan_rcv(struct sk_buff *skb,
523 			 struct tnl_ptk_info *tpi,
524 			 int gre_hdr_len)
525 {
526 	struct erspan_base_hdr *ershdr;
527 	const struct ipv6hdr *ipv6h;
528 	struct erspan_md2 *md2;
529 	struct ip6_tnl *tunnel;
530 	u8 ver;
531 
532 	ipv6h = ipv6_hdr(skb);
533 	ershdr = (struct erspan_base_hdr *)skb->data;
534 	ver = ershdr->ver;
535 
536 	tunnel = ip6gre_tunnel_lookup(skb->dev,
537 				      &ipv6h->saddr, &ipv6h->daddr, tpi->key,
538 				      tpi->proto);
539 	if (tunnel) {
540 		int len = erspan_hdr_len(ver);
541 
542 		if (unlikely(!pskb_may_pull(skb, len)))
543 			return PACKET_REJECT;
544 
545 		if (__iptunnel_pull_header(skb, len,
546 					   htons(ETH_P_TEB),
547 					   false, false) < 0)
548 			return PACKET_REJECT;
549 
550 		if (tunnel->parms.collect_md) {
551 			struct erspan_metadata *pkt_md, *md;
552 			struct metadata_dst *tun_dst;
553 			struct ip_tunnel_info *info;
554 			unsigned char *gh;
555 			__be64 tun_id;
556 			__be16 flags;
557 
558 			tpi->flags |= TUNNEL_KEY;
559 			flags = tpi->flags;
560 			tun_id = key32_to_tunnel_id(tpi->key);
561 
562 			tun_dst = ipv6_tun_rx_dst(skb, flags, tun_id,
563 						  sizeof(*md));
564 			if (!tun_dst)
565 				return PACKET_REJECT;
566 
567 			/* skb can be uncloned in __iptunnel_pull_header, so
568 			 * old pkt_md is no longer valid and we need to reset
569 			 * it
570 			 */
571 			gh = skb_network_header(skb) +
572 			     skb_network_header_len(skb);
573 			pkt_md = (struct erspan_metadata *)(gh + gre_hdr_len +
574 							    sizeof(*ershdr));
575 			info = &tun_dst->u.tun_info;
576 			md = ip_tunnel_info_opts(info);
577 			md->version = ver;
578 			md2 = &md->u.md2;
579 			memcpy(md2, pkt_md, ver == 1 ? ERSPAN_V1_MDSIZE :
580 						       ERSPAN_V2_MDSIZE);
581 			info->key.tun_flags |= TUNNEL_ERSPAN_OPT;
582 			info->options_len = sizeof(*md);
583 
584 			ip6_tnl_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error);
585 
586 		} else {
587 			ip6_tnl_rcv(tunnel, skb, tpi, NULL, log_ecn_error);
588 		}
589 
590 		return PACKET_RCVD;
591 	}
592 
593 	return PACKET_REJECT;
594 }
595 
596 static int gre_rcv(struct sk_buff *skb)
597 {
598 	struct tnl_ptk_info tpi;
599 	bool csum_err = false;
600 	int hdr_len;
601 
602 	hdr_len = gre_parse_header(skb, &tpi, &csum_err, htons(ETH_P_IPV6), 0);
603 	if (hdr_len < 0)
604 		goto drop;
605 
606 	if (iptunnel_pull_header(skb, hdr_len, tpi.proto, false))
607 		goto drop;
608 
609 	if (unlikely(tpi.proto == htons(ETH_P_ERSPAN) ||
610 		     tpi.proto == htons(ETH_P_ERSPAN2))) {
611 		if (ip6erspan_rcv(skb, &tpi, hdr_len) == PACKET_RCVD)
612 			return 0;
613 		goto out;
614 	}
615 
616 	if (ip6gre_rcv(skb, &tpi) == PACKET_RCVD)
617 		return 0;
618 
619 out:
620 	icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
621 drop:
622 	kfree_skb(skb);
623 	return 0;
624 }
625 
626 static int gre_handle_offloads(struct sk_buff *skb, bool csum)
627 {
628 	return iptunnel_handle_offloads(skb,
629 					csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE);
630 }
631 
632 static void prepare_ip6gre_xmit_ipv4(struct sk_buff *skb,
633 				     struct net_device *dev,
634 				     struct flowi6 *fl6, __u8 *dsfield,
635 				     int *encap_limit)
636 {
637 	const struct iphdr *iph = ip_hdr(skb);
638 	struct ip6_tnl *t = netdev_priv(dev);
639 
640 	if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
641 		*encap_limit = t->parms.encap_limit;
642 
643 	memcpy(fl6, &t->fl.u.ip6, sizeof(*fl6));
644 
645 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
646 		*dsfield = ipv4_get_dsfield(iph);
647 	else
648 		*dsfield = ip6_tclass(t->parms.flowinfo);
649 
650 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
651 		fl6->flowi6_mark = skb->mark;
652 	else
653 		fl6->flowi6_mark = t->parms.fwmark;
654 
655 	fl6->flowi6_uid = sock_net_uid(dev_net(dev), NULL);
656 }
657 
658 static int prepare_ip6gre_xmit_ipv6(struct sk_buff *skb,
659 				    struct net_device *dev,
660 				    struct flowi6 *fl6, __u8 *dsfield,
661 				    int *encap_limit)
662 {
663 	struct ipv6hdr *ipv6h;
664 	struct ip6_tnl *t = netdev_priv(dev);
665 	__u16 offset;
666 
667 	offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
668 	/* ip6_tnl_parse_tlv_enc_lim() might have reallocated skb->head */
669 	ipv6h = ipv6_hdr(skb);
670 
671 	if (offset > 0) {
672 		struct ipv6_tlv_tnl_enc_lim *tel;
673 
674 		tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset];
675 		if (tel->encap_limit == 0) {
676 			icmpv6_send(skb, ICMPV6_PARAMPROB,
677 				    ICMPV6_HDR_FIELD, offset + 2);
678 			return -1;
679 		}
680 		*encap_limit = tel->encap_limit - 1;
681 	} else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) {
682 		*encap_limit = t->parms.encap_limit;
683 	}
684 
685 	memcpy(fl6, &t->fl.u.ip6, sizeof(*fl6));
686 
687 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
688 		*dsfield = ipv6_get_dsfield(ipv6h);
689 	else
690 		*dsfield = ip6_tclass(t->parms.flowinfo);
691 
692 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
693 		fl6->flowlabel |= ip6_flowlabel(ipv6h);
694 
695 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
696 		fl6->flowi6_mark = skb->mark;
697 	else
698 		fl6->flowi6_mark = t->parms.fwmark;
699 
700 	fl6->flowi6_uid = sock_net_uid(dev_net(dev), NULL);
701 
702 	return 0;
703 }
704 
705 static netdev_tx_t __gre6_xmit(struct sk_buff *skb,
706 			       struct net_device *dev, __u8 dsfield,
707 			       struct flowi6 *fl6, int encap_limit,
708 			       __u32 *pmtu, __be16 proto)
709 {
710 	struct ip6_tnl *tunnel = netdev_priv(dev);
711 	__be16 protocol;
712 
713 	if (dev->type == ARPHRD_ETHER)
714 		IPCB(skb)->flags = 0;
715 
716 	if (dev->header_ops && dev->type == ARPHRD_IP6GRE)
717 		fl6->daddr = ((struct ipv6hdr *)skb->data)->daddr;
718 	else
719 		fl6->daddr = tunnel->parms.raddr;
720 
721 	if (skb_cow_head(skb, dev->needed_headroom ?: tunnel->hlen))
722 		return -ENOMEM;
723 
724 	/* Push GRE header. */
725 	protocol = (dev->type == ARPHRD_ETHER) ? htons(ETH_P_TEB) : proto;
726 
727 	if (tunnel->parms.collect_md) {
728 		struct ip_tunnel_info *tun_info;
729 		const struct ip_tunnel_key *key;
730 		__be16 flags;
731 
732 		tun_info = skb_tunnel_info(skb);
733 		if (unlikely(!tun_info ||
734 			     !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
735 			     ip_tunnel_info_af(tun_info) != AF_INET6))
736 			return -EINVAL;
737 
738 		key = &tun_info->key;
739 		memset(fl6, 0, sizeof(*fl6));
740 		fl6->flowi6_proto = IPPROTO_GRE;
741 		fl6->daddr = key->u.ipv6.dst;
742 		fl6->flowlabel = key->label;
743 		fl6->flowi6_uid = sock_net_uid(dev_net(dev), NULL);
744 
745 		dsfield = key->tos;
746 		flags = key->tun_flags &
747 			(TUNNEL_CSUM | TUNNEL_KEY | TUNNEL_SEQ);
748 		tunnel->tun_hlen = gre_calc_hlen(flags);
749 
750 		gre_build_header(skb, tunnel->tun_hlen,
751 				 flags, protocol,
752 				 tunnel_id_to_key32(tun_info->key.tun_id),
753 				 (flags & TUNNEL_SEQ) ? htonl(tunnel->o_seqno++)
754 						      : 0);
755 
756 	} else {
757 		if (tunnel->parms.o_flags & TUNNEL_SEQ)
758 			tunnel->o_seqno++;
759 
760 		gre_build_header(skb, tunnel->tun_hlen, tunnel->parms.o_flags,
761 				 protocol, tunnel->parms.o_key,
762 				 htonl(tunnel->o_seqno));
763 	}
764 
765 	return ip6_tnl_xmit(skb, dev, dsfield, fl6, encap_limit, pmtu,
766 			    NEXTHDR_GRE);
767 }
768 
769 static inline int ip6gre_xmit_ipv4(struct sk_buff *skb, struct net_device *dev)
770 {
771 	struct ip6_tnl *t = netdev_priv(dev);
772 	int encap_limit = -1;
773 	struct flowi6 fl6;
774 	__u8 dsfield = 0;
775 	__u32 mtu;
776 	int err;
777 
778 	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
779 
780 	if (!t->parms.collect_md)
781 		prepare_ip6gre_xmit_ipv4(skb, dev, &fl6,
782 					 &dsfield, &encap_limit);
783 
784 	err = gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM));
785 	if (err)
786 		return -1;
787 
788 	err = __gre6_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
789 			  skb->protocol);
790 	if (err != 0) {
791 		/* XXX: send ICMP error even if DF is not set. */
792 		if (err == -EMSGSIZE)
793 			icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
794 				  htonl(mtu));
795 		return -1;
796 	}
797 
798 	return 0;
799 }
800 
801 static inline int ip6gre_xmit_ipv6(struct sk_buff *skb, struct net_device *dev)
802 {
803 	struct ip6_tnl *t = netdev_priv(dev);
804 	struct ipv6hdr *ipv6h = ipv6_hdr(skb);
805 	int encap_limit = -1;
806 	struct flowi6 fl6;
807 	__u8 dsfield = 0;
808 	__u32 mtu;
809 	int err;
810 
811 	if (ipv6_addr_equal(&t->parms.raddr, &ipv6h->saddr))
812 		return -1;
813 
814 	if (!t->parms.collect_md &&
815 	    prepare_ip6gre_xmit_ipv6(skb, dev, &fl6, &dsfield, &encap_limit))
816 		return -1;
817 
818 	if (gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM)))
819 		return -1;
820 
821 	err = __gre6_xmit(skb, dev, dsfield, &fl6, encap_limit,
822 			  &mtu, skb->protocol);
823 	if (err != 0) {
824 		if (err == -EMSGSIZE)
825 			icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
826 		return -1;
827 	}
828 
829 	return 0;
830 }
831 
832 /**
833  * ip6gre_tnl_addr_conflict - compare packet addresses to tunnel's own
834  *   @t: the outgoing tunnel device
835  *   @hdr: IPv6 header from the incoming packet
836  *
837  * Description:
838  *   Avoid trivial tunneling loop by checking that tunnel exit-point
839  *   doesn't match source of incoming packet.
840  *
841  * Return:
842  *   1 if conflict,
843  *   0 else
844  **/
845 
846 static inline bool ip6gre_tnl_addr_conflict(const struct ip6_tnl *t,
847 	const struct ipv6hdr *hdr)
848 {
849 	return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
850 }
851 
852 static int ip6gre_xmit_other(struct sk_buff *skb, struct net_device *dev)
853 {
854 	struct ip6_tnl *t = netdev_priv(dev);
855 	int encap_limit = -1;
856 	struct flowi6 fl6;
857 	__u32 mtu;
858 	int err;
859 
860 	if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
861 		encap_limit = t->parms.encap_limit;
862 
863 	if (!t->parms.collect_md)
864 		memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
865 
866 	err = gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM));
867 	if (err)
868 		return err;
869 
870 	err = __gre6_xmit(skb, dev, 0, &fl6, encap_limit, &mtu, skb->protocol);
871 
872 	return err;
873 }
874 
875 static netdev_tx_t ip6gre_tunnel_xmit(struct sk_buff *skb,
876 	struct net_device *dev)
877 {
878 	struct ip6_tnl *t = netdev_priv(dev);
879 	struct net_device_stats *stats = &t->dev->stats;
880 	int ret;
881 
882 	if (!pskb_inet_may_pull(skb))
883 		goto tx_err;
884 
885 	if (!ip6_tnl_xmit_ctl(t, &t->parms.laddr, &t->parms.raddr))
886 		goto tx_err;
887 
888 	switch (skb->protocol) {
889 	case htons(ETH_P_IP):
890 		ret = ip6gre_xmit_ipv4(skb, dev);
891 		break;
892 	case htons(ETH_P_IPV6):
893 		ret = ip6gre_xmit_ipv6(skb, dev);
894 		break;
895 	default:
896 		ret = ip6gre_xmit_other(skb, dev);
897 		break;
898 	}
899 
900 	if (ret < 0)
901 		goto tx_err;
902 
903 	return NETDEV_TX_OK;
904 
905 tx_err:
906 	stats->tx_errors++;
907 	stats->tx_dropped++;
908 	kfree_skb(skb);
909 	return NETDEV_TX_OK;
910 }
911 
912 static netdev_tx_t ip6erspan_tunnel_xmit(struct sk_buff *skb,
913 					 struct net_device *dev)
914 {
915 	struct ip6_tnl *t = netdev_priv(dev);
916 	struct dst_entry *dst = skb_dst(skb);
917 	struct net_device_stats *stats;
918 	bool truncate = false;
919 	int encap_limit = -1;
920 	__u8 dsfield = false;
921 	struct flowi6 fl6;
922 	int err = -EINVAL;
923 	__be16 proto;
924 	__u32 mtu;
925 	int nhoff;
926 	int thoff;
927 
928 	if (!pskb_inet_may_pull(skb))
929 		goto tx_err;
930 
931 	if (!ip6_tnl_xmit_ctl(t, &t->parms.laddr, &t->parms.raddr))
932 		goto tx_err;
933 
934 	if (gre_handle_offloads(skb, false))
935 		goto tx_err;
936 
937 	if (skb->len > dev->mtu + dev->hard_header_len) {
938 		pskb_trim(skb, dev->mtu + dev->hard_header_len);
939 		truncate = true;
940 	}
941 
942 	nhoff = skb_network_header(skb) - skb_mac_header(skb);
943 	if (skb->protocol == htons(ETH_P_IP) &&
944 	    (ntohs(ip_hdr(skb)->tot_len) > skb->len - nhoff))
945 		truncate = true;
946 
947 	thoff = skb_transport_header(skb) - skb_mac_header(skb);
948 	if (skb->protocol == htons(ETH_P_IPV6) &&
949 	    (ntohs(ipv6_hdr(skb)->payload_len) > skb->len - thoff))
950 		truncate = true;
951 
952 	if (skb_cow_head(skb, dev->needed_headroom ?: t->hlen))
953 		goto tx_err;
954 
955 	t->parms.o_flags &= ~TUNNEL_KEY;
956 	IPCB(skb)->flags = 0;
957 
958 	/* For collect_md mode, derive fl6 from the tunnel key,
959 	 * for native mode, call prepare_ip6gre_xmit_{ipv4,ipv6}.
960 	 */
961 	if (t->parms.collect_md) {
962 		struct ip_tunnel_info *tun_info;
963 		const struct ip_tunnel_key *key;
964 		struct erspan_metadata *md;
965 		__be32 tun_id;
966 
967 		tun_info = skb_tunnel_info(skb);
968 		if (unlikely(!tun_info ||
969 			     !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
970 			     ip_tunnel_info_af(tun_info) != AF_INET6))
971 			goto tx_err;
972 
973 		key = &tun_info->key;
974 		memset(&fl6, 0, sizeof(fl6));
975 		fl6.flowi6_proto = IPPROTO_GRE;
976 		fl6.daddr = key->u.ipv6.dst;
977 		fl6.flowlabel = key->label;
978 		fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
979 
980 		dsfield = key->tos;
981 		if (!(tun_info->key.tun_flags & TUNNEL_ERSPAN_OPT))
982 			goto tx_err;
983 		md = ip_tunnel_info_opts(tun_info);
984 		if (!md)
985 			goto tx_err;
986 
987 		tun_id = tunnel_id_to_key32(key->tun_id);
988 		if (md->version == 1) {
989 			erspan_build_header(skb,
990 					    ntohl(tun_id),
991 					    ntohl(md->u.index), truncate,
992 					    false);
993 		} else if (md->version == 2) {
994 			erspan_build_header_v2(skb,
995 					       ntohl(tun_id),
996 					       md->u.md2.dir,
997 					       get_hwid(&md->u.md2),
998 					       truncate, false);
999 		} else {
1000 			goto tx_err;
1001 		}
1002 	} else {
1003 		switch (skb->protocol) {
1004 		case htons(ETH_P_IP):
1005 			memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1006 			prepare_ip6gre_xmit_ipv4(skb, dev, &fl6,
1007 						 &dsfield, &encap_limit);
1008 			break;
1009 		case htons(ETH_P_IPV6):
1010 			if (ipv6_addr_equal(&t->parms.raddr, &ipv6_hdr(skb)->saddr))
1011 				goto tx_err;
1012 			if (prepare_ip6gre_xmit_ipv6(skb, dev, &fl6,
1013 						     &dsfield, &encap_limit))
1014 				goto tx_err;
1015 			break;
1016 		default:
1017 			memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
1018 			break;
1019 		}
1020 
1021 		if (t->parms.erspan_ver == 1)
1022 			erspan_build_header(skb, ntohl(t->parms.o_key),
1023 					    t->parms.index,
1024 					    truncate, false);
1025 		else if (t->parms.erspan_ver == 2)
1026 			erspan_build_header_v2(skb, ntohl(t->parms.o_key),
1027 					       t->parms.dir,
1028 					       t->parms.hwid,
1029 					       truncate, false);
1030 		else
1031 			goto tx_err;
1032 
1033 		fl6.daddr = t->parms.raddr;
1034 	}
1035 
1036 	/* Push GRE header. */
1037 	proto = (t->parms.erspan_ver == 1) ? htons(ETH_P_ERSPAN)
1038 					   : htons(ETH_P_ERSPAN2);
1039 	gre_build_header(skb, 8, TUNNEL_SEQ, proto, 0, htonl(t->o_seqno++));
1040 
1041 	/* TooBig packet may have updated dst->dev's mtu */
1042 	if (!t->parms.collect_md && dst && dst_mtu(dst) > dst->dev->mtu)
1043 		dst->ops->update_pmtu(dst, NULL, skb, dst->dev->mtu);
1044 
1045 	err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
1046 			   NEXTHDR_GRE);
1047 	if (err != 0) {
1048 		/* XXX: send ICMP error even if DF is not set. */
1049 		if (err == -EMSGSIZE) {
1050 			if (skb->protocol == htons(ETH_P_IP))
1051 				icmp_send(skb, ICMP_DEST_UNREACH,
1052 					  ICMP_FRAG_NEEDED, htonl(mtu));
1053 			else
1054 				icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
1055 		}
1056 
1057 		goto tx_err;
1058 	}
1059 	return NETDEV_TX_OK;
1060 
1061 tx_err:
1062 	stats = &t->dev->stats;
1063 	stats->tx_errors++;
1064 	stats->tx_dropped++;
1065 	kfree_skb(skb);
1066 	return NETDEV_TX_OK;
1067 }
1068 
1069 static void ip6gre_tnl_link_config_common(struct ip6_tnl *t)
1070 {
1071 	struct net_device *dev = t->dev;
1072 	struct __ip6_tnl_parm *p = &t->parms;
1073 	struct flowi6 *fl6 = &t->fl.u.ip6;
1074 
1075 	if (dev->type != ARPHRD_ETHER) {
1076 		memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
1077 		memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
1078 	}
1079 
1080 	/* Set up flowi template */
1081 	fl6->saddr = p->laddr;
1082 	fl6->daddr = p->raddr;
1083 	fl6->flowi6_oif = p->link;
1084 	fl6->flowlabel = 0;
1085 	fl6->flowi6_proto = IPPROTO_GRE;
1086 
1087 	if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
1088 		fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
1089 	if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
1090 		fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
1091 
1092 	p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
1093 	p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
1094 
1095 	if (p->flags&IP6_TNL_F_CAP_XMIT &&
1096 			p->flags&IP6_TNL_F_CAP_RCV && dev->type != ARPHRD_ETHER)
1097 		dev->flags |= IFF_POINTOPOINT;
1098 	else
1099 		dev->flags &= ~IFF_POINTOPOINT;
1100 }
1101 
1102 static void ip6gre_tnl_link_config_route(struct ip6_tnl *t, int set_mtu,
1103 					 int t_hlen)
1104 {
1105 	const struct __ip6_tnl_parm *p = &t->parms;
1106 	struct net_device *dev = t->dev;
1107 
1108 	if (p->flags & IP6_TNL_F_CAP_XMIT) {
1109 		int strict = (ipv6_addr_type(&p->raddr) &
1110 			      (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
1111 
1112 		struct rt6_info *rt = rt6_lookup(t->net,
1113 						 &p->raddr, &p->laddr,
1114 						 p->link, NULL, strict);
1115 
1116 		if (!rt)
1117 			return;
1118 
1119 		if (rt->dst.dev) {
1120 			dev->needed_headroom = rt->dst.dev->hard_header_len +
1121 					       t_hlen;
1122 
1123 			if (set_mtu) {
1124 				dev->mtu = rt->dst.dev->mtu - t_hlen;
1125 				if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1126 					dev->mtu -= 8;
1127 				if (dev->type == ARPHRD_ETHER)
1128 					dev->mtu -= ETH_HLEN;
1129 
1130 				if (dev->mtu < IPV6_MIN_MTU)
1131 					dev->mtu = IPV6_MIN_MTU;
1132 			}
1133 		}
1134 		ip6_rt_put(rt);
1135 	}
1136 }
1137 
1138 static int ip6gre_calc_hlen(struct ip6_tnl *tunnel)
1139 {
1140 	int t_hlen;
1141 
1142 	tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags);
1143 	tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen;
1144 
1145 	t_hlen = tunnel->hlen + sizeof(struct ipv6hdr);
1146 	tunnel->dev->needed_headroom = LL_MAX_HEADER + t_hlen;
1147 	return t_hlen;
1148 }
1149 
1150 static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu)
1151 {
1152 	ip6gre_tnl_link_config_common(t);
1153 	ip6gre_tnl_link_config_route(t, set_mtu, ip6gre_calc_hlen(t));
1154 }
1155 
1156 static void ip6gre_tnl_copy_tnl_parm(struct ip6_tnl *t,
1157 				     const struct __ip6_tnl_parm *p)
1158 {
1159 	t->parms.laddr = p->laddr;
1160 	t->parms.raddr = p->raddr;
1161 	t->parms.flags = p->flags;
1162 	t->parms.hop_limit = p->hop_limit;
1163 	t->parms.encap_limit = p->encap_limit;
1164 	t->parms.flowinfo = p->flowinfo;
1165 	t->parms.link = p->link;
1166 	t->parms.proto = p->proto;
1167 	t->parms.i_key = p->i_key;
1168 	t->parms.o_key = p->o_key;
1169 	t->parms.i_flags = p->i_flags;
1170 	t->parms.o_flags = p->o_flags;
1171 	t->parms.fwmark = p->fwmark;
1172 	t->parms.erspan_ver = p->erspan_ver;
1173 	t->parms.index = p->index;
1174 	t->parms.dir = p->dir;
1175 	t->parms.hwid = p->hwid;
1176 	dst_cache_reset(&t->dst_cache);
1177 }
1178 
1179 static int ip6gre_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p,
1180 			     int set_mtu)
1181 {
1182 	ip6gre_tnl_copy_tnl_parm(t, p);
1183 	ip6gre_tnl_link_config(t, set_mtu);
1184 	return 0;
1185 }
1186 
1187 static void ip6gre_tnl_parm_from_user(struct __ip6_tnl_parm *p,
1188 	const struct ip6_tnl_parm2 *u)
1189 {
1190 	p->laddr = u->laddr;
1191 	p->raddr = u->raddr;
1192 	p->flags = u->flags;
1193 	p->hop_limit = u->hop_limit;
1194 	p->encap_limit = u->encap_limit;
1195 	p->flowinfo = u->flowinfo;
1196 	p->link = u->link;
1197 	p->i_key = u->i_key;
1198 	p->o_key = u->o_key;
1199 	p->i_flags = gre_flags_to_tnl_flags(u->i_flags);
1200 	p->o_flags = gre_flags_to_tnl_flags(u->o_flags);
1201 	memcpy(p->name, u->name, sizeof(u->name));
1202 }
1203 
1204 static void ip6gre_tnl_parm_to_user(struct ip6_tnl_parm2 *u,
1205 	const struct __ip6_tnl_parm *p)
1206 {
1207 	u->proto = IPPROTO_GRE;
1208 	u->laddr = p->laddr;
1209 	u->raddr = p->raddr;
1210 	u->flags = p->flags;
1211 	u->hop_limit = p->hop_limit;
1212 	u->encap_limit = p->encap_limit;
1213 	u->flowinfo = p->flowinfo;
1214 	u->link = p->link;
1215 	u->i_key = p->i_key;
1216 	u->o_key = p->o_key;
1217 	u->i_flags = gre_tnl_flags_to_gre_flags(p->i_flags);
1218 	u->o_flags = gre_tnl_flags_to_gre_flags(p->o_flags);
1219 	memcpy(u->name, p->name, sizeof(u->name));
1220 }
1221 
1222 static int ip6gre_tunnel_ioctl(struct net_device *dev,
1223 	struct ifreq *ifr, int cmd)
1224 {
1225 	int err = 0;
1226 	struct ip6_tnl_parm2 p;
1227 	struct __ip6_tnl_parm p1;
1228 	struct ip6_tnl *t = netdev_priv(dev);
1229 	struct net *net = t->net;
1230 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1231 
1232 	memset(&p1, 0, sizeof(p1));
1233 
1234 	switch (cmd) {
1235 	case SIOCGETTUNNEL:
1236 		if (dev == ign->fb_tunnel_dev) {
1237 			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1238 				err = -EFAULT;
1239 				break;
1240 			}
1241 			ip6gre_tnl_parm_from_user(&p1, &p);
1242 			t = ip6gre_tunnel_locate(net, &p1, 0);
1243 			if (!t)
1244 				t = netdev_priv(dev);
1245 		}
1246 		memset(&p, 0, sizeof(p));
1247 		ip6gre_tnl_parm_to_user(&p, &t->parms);
1248 		if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1249 			err = -EFAULT;
1250 		break;
1251 
1252 	case SIOCADDTUNNEL:
1253 	case SIOCCHGTUNNEL:
1254 		err = -EPERM;
1255 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1256 			goto done;
1257 
1258 		err = -EFAULT;
1259 		if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1260 			goto done;
1261 
1262 		err = -EINVAL;
1263 		if ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING))
1264 			goto done;
1265 
1266 		if (!(p.i_flags&GRE_KEY))
1267 			p.i_key = 0;
1268 		if (!(p.o_flags&GRE_KEY))
1269 			p.o_key = 0;
1270 
1271 		ip6gre_tnl_parm_from_user(&p1, &p);
1272 		t = ip6gre_tunnel_locate(net, &p1, cmd == SIOCADDTUNNEL);
1273 
1274 		if (dev != ign->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
1275 			if (t) {
1276 				if (t->dev != dev) {
1277 					err = -EEXIST;
1278 					break;
1279 				}
1280 			} else {
1281 				t = netdev_priv(dev);
1282 
1283 				ip6gre_tunnel_unlink(ign, t);
1284 				synchronize_net();
1285 				ip6gre_tnl_change(t, &p1, 1);
1286 				ip6gre_tunnel_link(ign, t);
1287 				netdev_state_change(dev);
1288 			}
1289 		}
1290 
1291 		if (t) {
1292 			err = 0;
1293 
1294 			memset(&p, 0, sizeof(p));
1295 			ip6gre_tnl_parm_to_user(&p, &t->parms);
1296 			if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1297 				err = -EFAULT;
1298 		} else
1299 			err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1300 		break;
1301 
1302 	case SIOCDELTUNNEL:
1303 		err = -EPERM;
1304 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1305 			goto done;
1306 
1307 		if (dev == ign->fb_tunnel_dev) {
1308 			err = -EFAULT;
1309 			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1310 				goto done;
1311 			err = -ENOENT;
1312 			ip6gre_tnl_parm_from_user(&p1, &p);
1313 			t = ip6gre_tunnel_locate(net, &p1, 0);
1314 			if (!t)
1315 				goto done;
1316 			err = -EPERM;
1317 			if (t == netdev_priv(ign->fb_tunnel_dev))
1318 				goto done;
1319 			dev = t->dev;
1320 		}
1321 		unregister_netdevice(dev);
1322 		err = 0;
1323 		break;
1324 
1325 	default:
1326 		err = -EINVAL;
1327 	}
1328 
1329 done:
1330 	return err;
1331 }
1332 
1333 static int ip6gre_header(struct sk_buff *skb, struct net_device *dev,
1334 			 unsigned short type, const void *daddr,
1335 			 const void *saddr, unsigned int len)
1336 {
1337 	struct ip6_tnl *t = netdev_priv(dev);
1338 	struct ipv6hdr *ipv6h;
1339 	__be16 *p;
1340 
1341 	ipv6h = skb_push(skb, t->hlen + sizeof(*ipv6h));
1342 	ip6_flow_hdr(ipv6h, 0, ip6_make_flowlabel(dev_net(dev), skb,
1343 						  t->fl.u.ip6.flowlabel,
1344 						  true, &t->fl.u.ip6));
1345 	ipv6h->hop_limit = t->parms.hop_limit;
1346 	ipv6h->nexthdr = NEXTHDR_GRE;
1347 	ipv6h->saddr = t->parms.laddr;
1348 	ipv6h->daddr = t->parms.raddr;
1349 
1350 	p = (__be16 *)(ipv6h + 1);
1351 	p[0] = t->parms.o_flags;
1352 	p[1] = htons(type);
1353 
1354 	/*
1355 	 *	Set the source hardware address.
1356 	 */
1357 
1358 	if (saddr)
1359 		memcpy(&ipv6h->saddr, saddr, sizeof(struct in6_addr));
1360 	if (daddr)
1361 		memcpy(&ipv6h->daddr, daddr, sizeof(struct in6_addr));
1362 	if (!ipv6_addr_any(&ipv6h->daddr))
1363 		return t->hlen;
1364 
1365 	return -t->hlen;
1366 }
1367 
1368 static const struct header_ops ip6gre_header_ops = {
1369 	.create	= ip6gre_header,
1370 };
1371 
1372 static const struct net_device_ops ip6gre_netdev_ops = {
1373 	.ndo_init		= ip6gre_tunnel_init,
1374 	.ndo_uninit		= ip6gre_tunnel_uninit,
1375 	.ndo_start_xmit		= ip6gre_tunnel_xmit,
1376 	.ndo_do_ioctl		= ip6gre_tunnel_ioctl,
1377 	.ndo_change_mtu		= ip6_tnl_change_mtu,
1378 	.ndo_get_stats64	= ip_tunnel_get_stats64,
1379 	.ndo_get_iflink		= ip6_tnl_get_iflink,
1380 };
1381 
1382 static void ip6gre_dev_free(struct net_device *dev)
1383 {
1384 	struct ip6_tnl *t = netdev_priv(dev);
1385 
1386 	gro_cells_destroy(&t->gro_cells);
1387 	dst_cache_destroy(&t->dst_cache);
1388 	free_percpu(dev->tstats);
1389 }
1390 
1391 static void ip6gre_tunnel_setup(struct net_device *dev)
1392 {
1393 	dev->netdev_ops = &ip6gre_netdev_ops;
1394 	dev->needs_free_netdev = true;
1395 	dev->priv_destructor = ip6gre_dev_free;
1396 
1397 	dev->type = ARPHRD_IP6GRE;
1398 
1399 	dev->flags |= IFF_NOARP;
1400 	dev->addr_len = sizeof(struct in6_addr);
1401 	netif_keep_dst(dev);
1402 	/* This perm addr will be used as interface identifier by IPv6 */
1403 	dev->addr_assign_type = NET_ADDR_RANDOM;
1404 	eth_random_addr(dev->perm_addr);
1405 }
1406 
1407 #define GRE6_FEATURES (NETIF_F_SG |		\
1408 		       NETIF_F_FRAGLIST |	\
1409 		       NETIF_F_HIGHDMA |	\
1410 		       NETIF_F_HW_CSUM)
1411 
1412 static void ip6gre_tnl_init_features(struct net_device *dev)
1413 {
1414 	struct ip6_tnl *nt = netdev_priv(dev);
1415 
1416 	dev->features		|= GRE6_FEATURES;
1417 	dev->hw_features	|= GRE6_FEATURES;
1418 
1419 	if (!(nt->parms.o_flags & TUNNEL_SEQ)) {
1420 		/* TCP offload with GRE SEQ is not supported, nor
1421 		 * can we support 2 levels of outer headers requiring
1422 		 * an update.
1423 		 */
1424 		if (!(nt->parms.o_flags & TUNNEL_CSUM) ||
1425 		    nt->encap.type == TUNNEL_ENCAP_NONE) {
1426 			dev->features    |= NETIF_F_GSO_SOFTWARE;
1427 			dev->hw_features |= NETIF_F_GSO_SOFTWARE;
1428 		}
1429 
1430 		/* Can use a lockless transmit, unless we generate
1431 		 * output sequences
1432 		 */
1433 		dev->features |= NETIF_F_LLTX;
1434 	}
1435 }
1436 
1437 static int ip6gre_tunnel_init_common(struct net_device *dev)
1438 {
1439 	struct ip6_tnl *tunnel;
1440 	int ret;
1441 	int t_hlen;
1442 
1443 	tunnel = netdev_priv(dev);
1444 
1445 	tunnel->dev = dev;
1446 	tunnel->net = dev_net(dev);
1447 	strcpy(tunnel->parms.name, dev->name);
1448 
1449 	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1450 	if (!dev->tstats)
1451 		return -ENOMEM;
1452 
1453 	ret = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL);
1454 	if (ret)
1455 		goto cleanup_alloc_pcpu_stats;
1456 
1457 	ret = gro_cells_init(&tunnel->gro_cells, dev);
1458 	if (ret)
1459 		goto cleanup_dst_cache_init;
1460 
1461 	t_hlen = ip6gre_calc_hlen(tunnel);
1462 	dev->mtu = ETH_DATA_LEN - t_hlen;
1463 	if (dev->type == ARPHRD_ETHER)
1464 		dev->mtu -= ETH_HLEN;
1465 	if (!(tunnel->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1466 		dev->mtu -= 8;
1467 
1468 	if (tunnel->parms.collect_md) {
1469 		dev->features |= NETIF_F_NETNS_LOCAL;
1470 		netif_keep_dst(dev);
1471 	}
1472 	ip6gre_tnl_init_features(dev);
1473 
1474 	return 0;
1475 
1476 cleanup_dst_cache_init:
1477 	dst_cache_destroy(&tunnel->dst_cache);
1478 cleanup_alloc_pcpu_stats:
1479 	free_percpu(dev->tstats);
1480 	dev->tstats = NULL;
1481 	return ret;
1482 }
1483 
1484 static int ip6gre_tunnel_init(struct net_device *dev)
1485 {
1486 	struct ip6_tnl *tunnel;
1487 	int ret;
1488 
1489 	ret = ip6gre_tunnel_init_common(dev);
1490 	if (ret)
1491 		return ret;
1492 
1493 	tunnel = netdev_priv(dev);
1494 
1495 	if (tunnel->parms.collect_md)
1496 		return 0;
1497 
1498 	memcpy(dev->dev_addr, &tunnel->parms.laddr, sizeof(struct in6_addr));
1499 	memcpy(dev->broadcast, &tunnel->parms.raddr, sizeof(struct in6_addr));
1500 
1501 	if (ipv6_addr_any(&tunnel->parms.raddr))
1502 		dev->header_ops = &ip6gre_header_ops;
1503 
1504 	return 0;
1505 }
1506 
1507 static void ip6gre_fb_tunnel_init(struct net_device *dev)
1508 {
1509 	struct ip6_tnl *tunnel = netdev_priv(dev);
1510 
1511 	tunnel->dev = dev;
1512 	tunnel->net = dev_net(dev);
1513 	strcpy(tunnel->parms.name, dev->name);
1514 
1515 	tunnel->hlen		= sizeof(struct ipv6hdr) + 4;
1516 
1517 	dev_hold(dev);
1518 }
1519 
1520 static struct inet6_protocol ip6gre_protocol __read_mostly = {
1521 	.handler     = gre_rcv,
1522 	.err_handler = ip6gre_err,
1523 	.flags       = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1524 };
1525 
1526 static void ip6gre_destroy_tunnels(struct net *net, struct list_head *head)
1527 {
1528 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1529 	struct net_device *dev, *aux;
1530 	int prio;
1531 
1532 	for_each_netdev_safe(net, dev, aux)
1533 		if (dev->rtnl_link_ops == &ip6gre_link_ops ||
1534 		    dev->rtnl_link_ops == &ip6gre_tap_ops ||
1535 		    dev->rtnl_link_ops == &ip6erspan_tap_ops)
1536 			unregister_netdevice_queue(dev, head);
1537 
1538 	for (prio = 0; prio < 4; prio++) {
1539 		int h;
1540 		for (h = 0; h < IP6_GRE_HASH_SIZE; h++) {
1541 			struct ip6_tnl *t;
1542 
1543 			t = rtnl_dereference(ign->tunnels[prio][h]);
1544 
1545 			while (t) {
1546 				/* If dev is in the same netns, it has already
1547 				 * been added to the list by the previous loop.
1548 				 */
1549 				if (!net_eq(dev_net(t->dev), net))
1550 					unregister_netdevice_queue(t->dev,
1551 								   head);
1552 				t = rtnl_dereference(t->next);
1553 			}
1554 		}
1555 	}
1556 }
1557 
1558 static int __net_init ip6gre_init_net(struct net *net)
1559 {
1560 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1561 	int err;
1562 
1563 	if (!net_has_fallback_tunnels(net))
1564 		return 0;
1565 	ign->fb_tunnel_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6gre0",
1566 					  NET_NAME_UNKNOWN,
1567 					  ip6gre_tunnel_setup);
1568 	if (!ign->fb_tunnel_dev) {
1569 		err = -ENOMEM;
1570 		goto err_alloc_dev;
1571 	}
1572 	dev_net_set(ign->fb_tunnel_dev, net);
1573 	/* FB netdevice is special: we have one, and only one per netns.
1574 	 * Allowing to move it to another netns is clearly unsafe.
1575 	 */
1576 	ign->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
1577 
1578 
1579 	ip6gre_fb_tunnel_init(ign->fb_tunnel_dev);
1580 	ign->fb_tunnel_dev->rtnl_link_ops = &ip6gre_link_ops;
1581 
1582 	err = register_netdev(ign->fb_tunnel_dev);
1583 	if (err)
1584 		goto err_reg_dev;
1585 
1586 	rcu_assign_pointer(ign->tunnels_wc[0],
1587 			   netdev_priv(ign->fb_tunnel_dev));
1588 	return 0;
1589 
1590 err_reg_dev:
1591 	free_netdev(ign->fb_tunnel_dev);
1592 err_alloc_dev:
1593 	return err;
1594 }
1595 
1596 static void __net_exit ip6gre_exit_batch_net(struct list_head *net_list)
1597 {
1598 	struct net *net;
1599 	LIST_HEAD(list);
1600 
1601 	rtnl_lock();
1602 	list_for_each_entry(net, net_list, exit_list)
1603 		ip6gre_destroy_tunnels(net, &list);
1604 	unregister_netdevice_many(&list);
1605 	rtnl_unlock();
1606 }
1607 
1608 static struct pernet_operations ip6gre_net_ops = {
1609 	.init = ip6gre_init_net,
1610 	.exit_batch = ip6gre_exit_batch_net,
1611 	.id   = &ip6gre_net_id,
1612 	.size = sizeof(struct ip6gre_net),
1613 };
1614 
1615 static int ip6gre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[],
1616 				  struct netlink_ext_ack *extack)
1617 {
1618 	__be16 flags;
1619 
1620 	if (!data)
1621 		return 0;
1622 
1623 	flags = 0;
1624 	if (data[IFLA_GRE_IFLAGS])
1625 		flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1626 	if (data[IFLA_GRE_OFLAGS])
1627 		flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1628 	if (flags & (GRE_VERSION|GRE_ROUTING))
1629 		return -EINVAL;
1630 
1631 	return 0;
1632 }
1633 
1634 static int ip6gre_tap_validate(struct nlattr *tb[], struct nlattr *data[],
1635 			       struct netlink_ext_ack *extack)
1636 {
1637 	struct in6_addr daddr;
1638 
1639 	if (tb[IFLA_ADDRESS]) {
1640 		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1641 			return -EINVAL;
1642 		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1643 			return -EADDRNOTAVAIL;
1644 	}
1645 
1646 	if (!data)
1647 		goto out;
1648 
1649 	if (data[IFLA_GRE_REMOTE]) {
1650 		daddr = nla_get_in6_addr(data[IFLA_GRE_REMOTE]);
1651 		if (ipv6_addr_any(&daddr))
1652 			return -EINVAL;
1653 	}
1654 
1655 out:
1656 	return ip6gre_tunnel_validate(tb, data, extack);
1657 }
1658 
1659 static int ip6erspan_tap_validate(struct nlattr *tb[], struct nlattr *data[],
1660 				  struct netlink_ext_ack *extack)
1661 {
1662 	__be16 flags = 0;
1663 	int ret, ver = 0;
1664 
1665 	if (!data)
1666 		return 0;
1667 
1668 	ret = ip6gre_tap_validate(tb, data, extack);
1669 	if (ret)
1670 		return ret;
1671 
1672 	/* ERSPAN should only have GRE sequence and key flag */
1673 	if (data[IFLA_GRE_OFLAGS])
1674 		flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1675 	if (data[IFLA_GRE_IFLAGS])
1676 		flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1677 	if (!data[IFLA_GRE_COLLECT_METADATA] &&
1678 	    flags != (GRE_SEQ | GRE_KEY))
1679 		return -EINVAL;
1680 
1681 	/* ERSPAN Session ID only has 10-bit. Since we reuse
1682 	 * 32-bit key field as ID, check it's range.
1683 	 */
1684 	if (data[IFLA_GRE_IKEY] &&
1685 	    (ntohl(nla_get_be32(data[IFLA_GRE_IKEY])) & ~ID_MASK))
1686 		return -EINVAL;
1687 
1688 	if (data[IFLA_GRE_OKEY] &&
1689 	    (ntohl(nla_get_be32(data[IFLA_GRE_OKEY])) & ~ID_MASK))
1690 		return -EINVAL;
1691 
1692 	if (data[IFLA_GRE_ERSPAN_VER]) {
1693 		ver = nla_get_u8(data[IFLA_GRE_ERSPAN_VER]);
1694 		if (ver != 1 && ver != 2)
1695 			return -EINVAL;
1696 	}
1697 
1698 	if (ver == 1) {
1699 		if (data[IFLA_GRE_ERSPAN_INDEX]) {
1700 			u32 index = nla_get_u32(data[IFLA_GRE_ERSPAN_INDEX]);
1701 
1702 			if (index & ~INDEX_MASK)
1703 				return -EINVAL;
1704 		}
1705 	} else if (ver == 2) {
1706 		if (data[IFLA_GRE_ERSPAN_DIR]) {
1707 			u16 dir = nla_get_u8(data[IFLA_GRE_ERSPAN_DIR]);
1708 
1709 			if (dir & ~(DIR_MASK >> DIR_OFFSET))
1710 				return -EINVAL;
1711 		}
1712 
1713 		if (data[IFLA_GRE_ERSPAN_HWID]) {
1714 			u16 hwid = nla_get_u16(data[IFLA_GRE_ERSPAN_HWID]);
1715 
1716 			if (hwid & ~(HWID_MASK >> HWID_OFFSET))
1717 				return -EINVAL;
1718 		}
1719 	}
1720 
1721 	return 0;
1722 }
1723 
1724 static void ip6erspan_set_version(struct nlattr *data[],
1725 				  struct __ip6_tnl_parm *parms)
1726 {
1727 	if (!data)
1728 		return;
1729 
1730 	parms->erspan_ver = 1;
1731 	if (data[IFLA_GRE_ERSPAN_VER])
1732 		parms->erspan_ver = nla_get_u8(data[IFLA_GRE_ERSPAN_VER]);
1733 
1734 	if (parms->erspan_ver == 1) {
1735 		if (data[IFLA_GRE_ERSPAN_INDEX])
1736 			parms->index = nla_get_u32(data[IFLA_GRE_ERSPAN_INDEX]);
1737 	} else if (parms->erspan_ver == 2) {
1738 		if (data[IFLA_GRE_ERSPAN_DIR])
1739 			parms->dir = nla_get_u8(data[IFLA_GRE_ERSPAN_DIR]);
1740 		if (data[IFLA_GRE_ERSPAN_HWID])
1741 			parms->hwid = nla_get_u16(data[IFLA_GRE_ERSPAN_HWID]);
1742 	}
1743 }
1744 
1745 static void ip6gre_netlink_parms(struct nlattr *data[],
1746 				struct __ip6_tnl_parm *parms)
1747 {
1748 	memset(parms, 0, sizeof(*parms));
1749 
1750 	if (!data)
1751 		return;
1752 
1753 	if (data[IFLA_GRE_LINK])
1754 		parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
1755 
1756 	if (data[IFLA_GRE_IFLAGS])
1757 		parms->i_flags = gre_flags_to_tnl_flags(
1758 				nla_get_be16(data[IFLA_GRE_IFLAGS]));
1759 
1760 	if (data[IFLA_GRE_OFLAGS])
1761 		parms->o_flags = gre_flags_to_tnl_flags(
1762 				nla_get_be16(data[IFLA_GRE_OFLAGS]));
1763 
1764 	if (data[IFLA_GRE_IKEY])
1765 		parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
1766 
1767 	if (data[IFLA_GRE_OKEY])
1768 		parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
1769 
1770 	if (data[IFLA_GRE_LOCAL])
1771 		parms->laddr = nla_get_in6_addr(data[IFLA_GRE_LOCAL]);
1772 
1773 	if (data[IFLA_GRE_REMOTE])
1774 		parms->raddr = nla_get_in6_addr(data[IFLA_GRE_REMOTE]);
1775 
1776 	if (data[IFLA_GRE_TTL])
1777 		parms->hop_limit = nla_get_u8(data[IFLA_GRE_TTL]);
1778 
1779 	if (data[IFLA_GRE_ENCAP_LIMIT])
1780 		parms->encap_limit = nla_get_u8(data[IFLA_GRE_ENCAP_LIMIT]);
1781 
1782 	if (data[IFLA_GRE_FLOWINFO])
1783 		parms->flowinfo = nla_get_be32(data[IFLA_GRE_FLOWINFO]);
1784 
1785 	if (data[IFLA_GRE_FLAGS])
1786 		parms->flags = nla_get_u32(data[IFLA_GRE_FLAGS]);
1787 
1788 	if (data[IFLA_GRE_FWMARK])
1789 		parms->fwmark = nla_get_u32(data[IFLA_GRE_FWMARK]);
1790 
1791 	if (data[IFLA_GRE_COLLECT_METADATA])
1792 		parms->collect_md = true;
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 static bool ip6gre_netlink_encap_parms(struct nlattr *data[],
1904 				       struct ip_tunnel_encap *ipencap)
1905 {
1906 	bool ret = false;
1907 
1908 	memset(ipencap, 0, sizeof(*ipencap));
1909 
1910 	if (!data)
1911 		return ret;
1912 
1913 	if (data[IFLA_GRE_ENCAP_TYPE]) {
1914 		ret = true;
1915 		ipencap->type = nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]);
1916 	}
1917 
1918 	if (data[IFLA_GRE_ENCAP_FLAGS]) {
1919 		ret = true;
1920 		ipencap->flags = nla_get_u16(data[IFLA_GRE_ENCAP_FLAGS]);
1921 	}
1922 
1923 	if (data[IFLA_GRE_ENCAP_SPORT]) {
1924 		ret = true;
1925 		ipencap->sport = nla_get_be16(data[IFLA_GRE_ENCAP_SPORT]);
1926 	}
1927 
1928 	if (data[IFLA_GRE_ENCAP_DPORT]) {
1929 		ret = true;
1930 		ipencap->dport = nla_get_be16(data[IFLA_GRE_ENCAP_DPORT]);
1931 	}
1932 
1933 	return ret;
1934 }
1935 
1936 static int ip6gre_newlink_common(struct net *src_net, struct net_device *dev,
1937 				 struct nlattr *tb[], struct nlattr *data[],
1938 				 struct netlink_ext_ack *extack)
1939 {
1940 	struct ip6_tnl *nt;
1941 	struct ip_tunnel_encap ipencap;
1942 	int err;
1943 
1944 	nt = netdev_priv(dev);
1945 
1946 	if (ip6gre_netlink_encap_parms(data, &ipencap)) {
1947 		int err = ip6_tnl_encap_setup(nt, &ipencap);
1948 
1949 		if (err < 0)
1950 			return err;
1951 	}
1952 
1953 	if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
1954 		eth_hw_addr_random(dev);
1955 
1956 	nt->dev = dev;
1957 	nt->net = dev_net(dev);
1958 
1959 	err = register_netdevice(dev);
1960 	if (err)
1961 		goto out;
1962 
1963 	if (tb[IFLA_MTU])
1964 		ip6_tnl_change_mtu(dev, nla_get_u32(tb[IFLA_MTU]));
1965 
1966 	dev_hold(dev);
1967 
1968 out:
1969 	return err;
1970 }
1971 
1972 static int ip6gre_newlink(struct net *src_net, struct net_device *dev,
1973 			  struct nlattr *tb[], struct nlattr *data[],
1974 			  struct netlink_ext_ack *extack)
1975 {
1976 	struct ip6_tnl *nt = netdev_priv(dev);
1977 	struct net *net = dev_net(dev);
1978 	struct ip6gre_net *ign;
1979 	int err;
1980 
1981 	ip6gre_netlink_parms(data, &nt->parms);
1982 	ign = net_generic(net, ip6gre_net_id);
1983 
1984 	if (nt->parms.collect_md) {
1985 		if (rtnl_dereference(ign->collect_md_tun))
1986 			return -EEXIST;
1987 	} else {
1988 		if (ip6gre_tunnel_find(net, &nt->parms, dev->type))
1989 			return -EEXIST;
1990 	}
1991 
1992 	err = ip6gre_newlink_common(src_net, dev, tb, data, extack);
1993 	if (!err) {
1994 		ip6gre_tnl_link_config(nt, !tb[IFLA_MTU]);
1995 		ip6gre_tunnel_link_md(ign, nt);
1996 		ip6gre_tunnel_link(net_generic(net, ip6gre_net_id), nt);
1997 	}
1998 	return err;
1999 }
2000 
2001 static struct ip6_tnl *
2002 ip6gre_changelink_common(struct net_device *dev, struct nlattr *tb[],
2003 			 struct nlattr *data[], struct __ip6_tnl_parm *p_p,
2004 			 struct netlink_ext_ack *extack)
2005 {
2006 	struct ip6_tnl *t, *nt = netdev_priv(dev);
2007 	struct net *net = nt->net;
2008 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
2009 	struct ip_tunnel_encap ipencap;
2010 
2011 	if (dev == ign->fb_tunnel_dev)
2012 		return ERR_PTR(-EINVAL);
2013 
2014 	if (ip6gre_netlink_encap_parms(data, &ipencap)) {
2015 		int err = ip6_tnl_encap_setup(nt, &ipencap);
2016 
2017 		if (err < 0)
2018 			return ERR_PTR(err);
2019 	}
2020 
2021 	ip6gre_netlink_parms(data, p_p);
2022 
2023 	t = ip6gre_tunnel_locate(net, p_p, 0);
2024 
2025 	if (t) {
2026 		if (t->dev != dev)
2027 			return ERR_PTR(-EEXIST);
2028 	} else {
2029 		t = nt;
2030 	}
2031 
2032 	return t;
2033 }
2034 
2035 static int ip6gre_changelink(struct net_device *dev, struct nlattr *tb[],
2036 			     struct nlattr *data[],
2037 			     struct netlink_ext_ack *extack)
2038 {
2039 	struct ip6_tnl *t = netdev_priv(dev);
2040 	struct ip6gre_net *ign = net_generic(t->net, ip6gre_net_id);
2041 	struct __ip6_tnl_parm p;
2042 
2043 	t = ip6gre_changelink_common(dev, tb, data, &p, extack);
2044 	if (IS_ERR(t))
2045 		return PTR_ERR(t);
2046 
2047 	ip6gre_tunnel_unlink_md(ign, t);
2048 	ip6gre_tunnel_unlink(ign, t);
2049 	ip6gre_tnl_change(t, &p, !tb[IFLA_MTU]);
2050 	ip6gre_tunnel_link_md(ign, t);
2051 	ip6gre_tunnel_link(ign, t);
2052 	return 0;
2053 }
2054 
2055 static void ip6gre_dellink(struct net_device *dev, struct list_head *head)
2056 {
2057 	struct net *net = dev_net(dev);
2058 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
2059 
2060 	if (dev != ign->fb_tunnel_dev)
2061 		unregister_netdevice_queue(dev, head);
2062 }
2063 
2064 static size_t ip6gre_get_size(const struct net_device *dev)
2065 {
2066 	return
2067 		/* IFLA_GRE_LINK */
2068 		nla_total_size(4) +
2069 		/* IFLA_GRE_IFLAGS */
2070 		nla_total_size(2) +
2071 		/* IFLA_GRE_OFLAGS */
2072 		nla_total_size(2) +
2073 		/* IFLA_GRE_IKEY */
2074 		nla_total_size(4) +
2075 		/* IFLA_GRE_OKEY */
2076 		nla_total_size(4) +
2077 		/* IFLA_GRE_LOCAL */
2078 		nla_total_size(sizeof(struct in6_addr)) +
2079 		/* IFLA_GRE_REMOTE */
2080 		nla_total_size(sizeof(struct in6_addr)) +
2081 		/* IFLA_GRE_TTL */
2082 		nla_total_size(1) +
2083 		/* IFLA_GRE_ENCAP_LIMIT */
2084 		nla_total_size(1) +
2085 		/* IFLA_GRE_FLOWINFO */
2086 		nla_total_size(4) +
2087 		/* IFLA_GRE_FLAGS */
2088 		nla_total_size(4) +
2089 		/* IFLA_GRE_ENCAP_TYPE */
2090 		nla_total_size(2) +
2091 		/* IFLA_GRE_ENCAP_FLAGS */
2092 		nla_total_size(2) +
2093 		/* IFLA_GRE_ENCAP_SPORT */
2094 		nla_total_size(2) +
2095 		/* IFLA_GRE_ENCAP_DPORT */
2096 		nla_total_size(2) +
2097 		/* IFLA_GRE_COLLECT_METADATA */
2098 		nla_total_size(0) +
2099 		/* IFLA_GRE_FWMARK */
2100 		nla_total_size(4) +
2101 		/* IFLA_GRE_ERSPAN_INDEX */
2102 		nla_total_size(4) +
2103 		0;
2104 }
2105 
2106 static int ip6gre_fill_info(struct sk_buff *skb, const struct net_device *dev)
2107 {
2108 	struct ip6_tnl *t = netdev_priv(dev);
2109 	struct __ip6_tnl_parm *p = &t->parms;
2110 	__be16 o_flags = p->o_flags;
2111 
2112 	if (p->erspan_ver == 1 || p->erspan_ver == 2) {
2113 		if (!p->collect_md)
2114 			o_flags |= TUNNEL_KEY;
2115 
2116 		if (nla_put_u8(skb, IFLA_GRE_ERSPAN_VER, p->erspan_ver))
2117 			goto nla_put_failure;
2118 
2119 		if (p->erspan_ver == 1) {
2120 			if (nla_put_u32(skb, IFLA_GRE_ERSPAN_INDEX, p->index))
2121 				goto nla_put_failure;
2122 		} else {
2123 			if (nla_put_u8(skb, IFLA_GRE_ERSPAN_DIR, p->dir))
2124 				goto nla_put_failure;
2125 			if (nla_put_u16(skb, IFLA_GRE_ERSPAN_HWID, p->hwid))
2126 				goto nla_put_failure;
2127 		}
2128 	}
2129 
2130 	if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
2131 	    nla_put_be16(skb, IFLA_GRE_IFLAGS,
2132 			 gre_tnl_flags_to_gre_flags(p->i_flags)) ||
2133 	    nla_put_be16(skb, IFLA_GRE_OFLAGS,
2134 			 gre_tnl_flags_to_gre_flags(o_flags)) ||
2135 	    nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
2136 	    nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
2137 	    nla_put_in6_addr(skb, IFLA_GRE_LOCAL, &p->laddr) ||
2138 	    nla_put_in6_addr(skb, IFLA_GRE_REMOTE, &p->raddr) ||
2139 	    nla_put_u8(skb, IFLA_GRE_TTL, p->hop_limit) ||
2140 	    nla_put_u8(skb, IFLA_GRE_ENCAP_LIMIT, p->encap_limit) ||
2141 	    nla_put_be32(skb, IFLA_GRE_FLOWINFO, p->flowinfo) ||
2142 	    nla_put_u32(skb, IFLA_GRE_FLAGS, p->flags) ||
2143 	    nla_put_u32(skb, IFLA_GRE_FWMARK, p->fwmark))
2144 		goto nla_put_failure;
2145 
2146 	if (nla_put_u16(skb, IFLA_GRE_ENCAP_TYPE,
2147 			t->encap.type) ||
2148 	    nla_put_be16(skb, IFLA_GRE_ENCAP_SPORT,
2149 			 t->encap.sport) ||
2150 	    nla_put_be16(skb, IFLA_GRE_ENCAP_DPORT,
2151 			 t->encap.dport) ||
2152 	    nla_put_u16(skb, IFLA_GRE_ENCAP_FLAGS,
2153 			t->encap.flags))
2154 		goto nla_put_failure;
2155 
2156 	if (p->collect_md) {
2157 		if (nla_put_flag(skb, IFLA_GRE_COLLECT_METADATA))
2158 			goto nla_put_failure;
2159 	}
2160 
2161 	return 0;
2162 
2163 nla_put_failure:
2164 	return -EMSGSIZE;
2165 }
2166 
2167 static const struct nla_policy ip6gre_policy[IFLA_GRE_MAX + 1] = {
2168 	[IFLA_GRE_LINK]        = { .type = NLA_U32 },
2169 	[IFLA_GRE_IFLAGS]      = { .type = NLA_U16 },
2170 	[IFLA_GRE_OFLAGS]      = { .type = NLA_U16 },
2171 	[IFLA_GRE_IKEY]        = { .type = NLA_U32 },
2172 	[IFLA_GRE_OKEY]        = { .type = NLA_U32 },
2173 	[IFLA_GRE_LOCAL]       = { .len = FIELD_SIZEOF(struct ipv6hdr, saddr) },
2174 	[IFLA_GRE_REMOTE]      = { .len = FIELD_SIZEOF(struct ipv6hdr, daddr) },
2175 	[IFLA_GRE_TTL]         = { .type = NLA_U8 },
2176 	[IFLA_GRE_ENCAP_LIMIT] = { .type = NLA_U8 },
2177 	[IFLA_GRE_FLOWINFO]    = { .type = NLA_U32 },
2178 	[IFLA_GRE_FLAGS]       = { .type = NLA_U32 },
2179 	[IFLA_GRE_ENCAP_TYPE]   = { .type = NLA_U16 },
2180 	[IFLA_GRE_ENCAP_FLAGS]  = { .type = NLA_U16 },
2181 	[IFLA_GRE_ENCAP_SPORT]  = { .type = NLA_U16 },
2182 	[IFLA_GRE_ENCAP_DPORT]  = { .type = NLA_U16 },
2183 	[IFLA_GRE_COLLECT_METADATA] = { .type = NLA_FLAG },
2184 	[IFLA_GRE_FWMARK]       = { .type = NLA_U32 },
2185 	[IFLA_GRE_ERSPAN_INDEX] = { .type = NLA_U32 },
2186 	[IFLA_GRE_ERSPAN_VER]	= { .type = NLA_U8 },
2187 	[IFLA_GRE_ERSPAN_DIR]	= { .type = NLA_U8 },
2188 	[IFLA_GRE_ERSPAN_HWID]	= { .type = NLA_U16 },
2189 };
2190 
2191 static void ip6erspan_tap_setup(struct net_device *dev)
2192 {
2193 	ether_setup(dev);
2194 
2195 	dev->netdev_ops = &ip6erspan_netdev_ops;
2196 	dev->needs_free_netdev = true;
2197 	dev->priv_destructor = ip6gre_dev_free;
2198 
2199 	dev->features |= NETIF_F_NETNS_LOCAL;
2200 	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
2201 	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
2202 	netif_keep_dst(dev);
2203 }
2204 
2205 static int ip6erspan_newlink(struct net *src_net, struct net_device *dev,
2206 			     struct nlattr *tb[], struct nlattr *data[],
2207 			     struct netlink_ext_ack *extack)
2208 {
2209 	struct ip6_tnl *nt = netdev_priv(dev);
2210 	struct net *net = dev_net(dev);
2211 	struct ip6gre_net *ign;
2212 	int err;
2213 
2214 	ip6gre_netlink_parms(data, &nt->parms);
2215 	ip6erspan_set_version(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 	ip6erspan_set_version(data, &p);
2262 	ip6gre_tunnel_unlink_md(ign, t);
2263 	ip6gre_tunnel_unlink(ign, t);
2264 	ip6erspan_tnl_change(t, &p, !tb[IFLA_MTU]);
2265 	ip6erspan_tunnel_link_md(ign, t);
2266 	ip6gre_tunnel_link(ign, t);
2267 	return 0;
2268 }
2269 
2270 static struct rtnl_link_ops ip6gre_link_ops __read_mostly = {
2271 	.kind		= "ip6gre",
2272 	.maxtype	= IFLA_GRE_MAX,
2273 	.policy		= ip6gre_policy,
2274 	.priv_size	= sizeof(struct ip6_tnl),
2275 	.setup		= ip6gre_tunnel_setup,
2276 	.validate	= ip6gre_tunnel_validate,
2277 	.newlink	= ip6gre_newlink,
2278 	.changelink	= ip6gre_changelink,
2279 	.dellink	= ip6gre_dellink,
2280 	.get_size	= ip6gre_get_size,
2281 	.fill_info	= ip6gre_fill_info,
2282 	.get_link_net	= ip6_tnl_get_link_net,
2283 };
2284 
2285 static struct rtnl_link_ops ip6gre_tap_ops __read_mostly = {
2286 	.kind		= "ip6gretap",
2287 	.maxtype	= IFLA_GRE_MAX,
2288 	.policy		= ip6gre_policy,
2289 	.priv_size	= sizeof(struct ip6_tnl),
2290 	.setup		= ip6gre_tap_setup,
2291 	.validate	= ip6gre_tap_validate,
2292 	.newlink	= ip6gre_newlink,
2293 	.changelink	= ip6gre_changelink,
2294 	.get_size	= ip6gre_get_size,
2295 	.fill_info	= ip6gre_fill_info,
2296 	.get_link_net	= ip6_tnl_get_link_net,
2297 };
2298 
2299 static struct rtnl_link_ops ip6erspan_tap_ops __read_mostly = {
2300 	.kind		= "ip6erspan",
2301 	.maxtype	= IFLA_GRE_MAX,
2302 	.policy		= ip6gre_policy,
2303 	.priv_size	= sizeof(struct ip6_tnl),
2304 	.setup		= ip6erspan_tap_setup,
2305 	.validate	= ip6erspan_tap_validate,
2306 	.newlink	= ip6erspan_newlink,
2307 	.changelink	= ip6erspan_changelink,
2308 	.get_size	= ip6gre_get_size,
2309 	.fill_info	= ip6gre_fill_info,
2310 	.get_link_net	= ip6_tnl_get_link_net,
2311 };
2312 
2313 /*
2314  *	And now the modules code and kernel interface.
2315  */
2316 
2317 static int __init ip6gre_init(void)
2318 {
2319 	int err;
2320 
2321 	pr_info("GRE over IPv6 tunneling driver\n");
2322 
2323 	err = register_pernet_device(&ip6gre_net_ops);
2324 	if (err < 0)
2325 		return err;
2326 
2327 	err = inet6_add_protocol(&ip6gre_protocol, IPPROTO_GRE);
2328 	if (err < 0) {
2329 		pr_info("%s: can't add protocol\n", __func__);
2330 		goto add_proto_failed;
2331 	}
2332 
2333 	err = rtnl_link_register(&ip6gre_link_ops);
2334 	if (err < 0)
2335 		goto rtnl_link_failed;
2336 
2337 	err = rtnl_link_register(&ip6gre_tap_ops);
2338 	if (err < 0)
2339 		goto tap_ops_failed;
2340 
2341 	err = rtnl_link_register(&ip6erspan_tap_ops);
2342 	if (err < 0)
2343 		goto erspan_link_failed;
2344 
2345 out:
2346 	return err;
2347 
2348 erspan_link_failed:
2349 	rtnl_link_unregister(&ip6gre_tap_ops);
2350 tap_ops_failed:
2351 	rtnl_link_unregister(&ip6gre_link_ops);
2352 rtnl_link_failed:
2353 	inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
2354 add_proto_failed:
2355 	unregister_pernet_device(&ip6gre_net_ops);
2356 	goto out;
2357 }
2358 
2359 static void __exit ip6gre_fini(void)
2360 {
2361 	rtnl_link_unregister(&ip6gre_tap_ops);
2362 	rtnl_link_unregister(&ip6gre_link_ops);
2363 	rtnl_link_unregister(&ip6erspan_tap_ops);
2364 	inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
2365 	unregister_pernet_device(&ip6gre_net_ops);
2366 }
2367 
2368 module_init(ip6gre_init);
2369 module_exit(ip6gre_fini);
2370 MODULE_LICENSE("GPL");
2371 MODULE_AUTHOR("D. Kozlov (xeb@mail.ru)");
2372 MODULE_DESCRIPTION("GRE over IPv6 tunneling device");
2373 MODULE_ALIAS_RTNL_LINK("ip6gre");
2374 MODULE_ALIAS_RTNL_LINK("ip6gretap");
2375 MODULE_ALIAS_RTNL_LINK("ip6erspan");
2376 MODULE_ALIAS_NETDEV("ip6gre0");
2377