xref: /linux/net/ipv6/ip6_gre.c (revision 18f90d372cf35b387663f1567de701e5393f6eb5)
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,
528 			 struct tnl_ptk_info *tpi,
529 			 int gre_hdr_len)
530 {
531 	struct erspan_base_hdr *ershdr;
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 		if (__iptunnel_pull_header(skb, len,
551 					   htons(ETH_P_TEB),
552 					   false, false) < 0)
553 			return PACKET_REJECT;
554 
555 		if (tunnel->parms.collect_md) {
556 			struct erspan_metadata *pkt_md, *md;
557 			struct metadata_dst *tun_dst;
558 			struct ip_tunnel_info *info;
559 			unsigned char *gh;
560 			__be64 tun_id;
561 			__be16 flags;
562 
563 			tpi->flags |= TUNNEL_KEY;
564 			flags = tpi->flags;
565 			tun_id = key32_to_tunnel_id(tpi->key);
566 
567 			tun_dst = ipv6_tun_rx_dst(skb, flags, tun_id,
568 						  sizeof(*md));
569 			if (!tun_dst)
570 				return PACKET_REJECT;
571 
572 			/* skb can be uncloned in __iptunnel_pull_header, so
573 			 * old pkt_md is no longer valid and we need to reset
574 			 * it
575 			 */
576 			gh = skb_network_header(skb) +
577 			     skb_network_header_len(skb);
578 			pkt_md = (struct erspan_metadata *)(gh + gre_hdr_len +
579 							    sizeof(*ershdr));
580 			info = &tun_dst->u.tun_info;
581 			md = ip_tunnel_info_opts(info);
582 			md->version = ver;
583 			md2 = &md->u.md2;
584 			memcpy(md2, pkt_md, ver == 1 ? ERSPAN_V1_MDSIZE :
585 						       ERSPAN_V2_MDSIZE);
586 			info->key.tun_flags |= TUNNEL_ERSPAN_OPT;
587 			info->options_len = sizeof(*md);
588 
589 			ip6_tnl_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error);
590 
591 		} else {
592 			ip6_tnl_rcv(tunnel, skb, tpi, NULL, log_ecn_error);
593 		}
594 
595 		return PACKET_RCVD;
596 	}
597 
598 	return PACKET_REJECT;
599 }
600 
601 static int gre_rcv(struct sk_buff *skb)
602 {
603 	struct tnl_ptk_info tpi;
604 	bool csum_err = false;
605 	int hdr_len;
606 
607 	hdr_len = gre_parse_header(skb, &tpi, &csum_err, htons(ETH_P_IPV6), 0);
608 	if (hdr_len < 0)
609 		goto drop;
610 
611 	if (iptunnel_pull_header(skb, hdr_len, tpi.proto, false))
612 		goto drop;
613 
614 	if (unlikely(tpi.proto == htons(ETH_P_ERSPAN) ||
615 		     tpi.proto == htons(ETH_P_ERSPAN2))) {
616 		if (ip6erspan_rcv(skb, &tpi, hdr_len) == PACKET_RCVD)
617 			return 0;
618 		goto out;
619 	}
620 
621 	if (ip6gre_rcv(skb, &tpi) == PACKET_RCVD)
622 		return 0;
623 
624 out:
625 	icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
626 drop:
627 	kfree_skb(skb);
628 	return 0;
629 }
630 
631 static int gre_handle_offloads(struct sk_buff *skb, bool csum)
632 {
633 	return iptunnel_handle_offloads(skb,
634 					csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE);
635 }
636 
637 static void prepare_ip6gre_xmit_ipv4(struct sk_buff *skb,
638 				     struct net_device *dev,
639 				     struct flowi6 *fl6, __u8 *dsfield,
640 				     int *encap_limit)
641 {
642 	const struct iphdr *iph = ip_hdr(skb);
643 	struct ip6_tnl *t = netdev_priv(dev);
644 
645 	if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
646 		*encap_limit = t->parms.encap_limit;
647 
648 	memcpy(fl6, &t->fl.u.ip6, sizeof(*fl6));
649 
650 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
651 		*dsfield = ipv4_get_dsfield(iph);
652 	else
653 		*dsfield = ip6_tclass(t->parms.flowinfo);
654 
655 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
656 		fl6->flowi6_mark = skb->mark;
657 	else
658 		fl6->flowi6_mark = t->parms.fwmark;
659 
660 	fl6->flowi6_uid = sock_net_uid(dev_net(dev), NULL);
661 }
662 
663 static int prepare_ip6gre_xmit_ipv6(struct sk_buff *skb,
664 				    struct net_device *dev,
665 				    struct flowi6 *fl6, __u8 *dsfield,
666 				    int *encap_limit)
667 {
668 	struct ipv6hdr *ipv6h = ipv6_hdr(skb);
669 	struct ip6_tnl *t = netdev_priv(dev);
670 	__u16 offset;
671 
672 	offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
673 	/* ip6_tnl_parse_tlv_enc_lim() might have reallocated skb->head */
674 
675 	if (offset > 0) {
676 		struct ipv6_tlv_tnl_enc_lim *tel;
677 
678 		tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset];
679 		if (tel->encap_limit == 0) {
680 			icmpv6_send(skb, ICMPV6_PARAMPROB,
681 				    ICMPV6_HDR_FIELD, offset + 2);
682 			return -1;
683 		}
684 		*encap_limit = tel->encap_limit - 1;
685 	} else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) {
686 		*encap_limit = t->parms.encap_limit;
687 	}
688 
689 	memcpy(fl6, &t->fl.u.ip6, sizeof(*fl6));
690 
691 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
692 		*dsfield = ipv6_get_dsfield(ipv6h);
693 	else
694 		*dsfield = ip6_tclass(t->parms.flowinfo);
695 
696 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
697 		fl6->flowlabel |= ip6_flowlabel(ipv6h);
698 
699 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
700 		fl6->flowi6_mark = skb->mark;
701 	else
702 		fl6->flowi6_mark = t->parms.fwmark;
703 
704 	fl6->flowi6_uid = sock_net_uid(dev_net(dev), NULL);
705 
706 	return 0;
707 }
708 
709 static netdev_tx_t __gre6_xmit(struct sk_buff *skb,
710 			       struct net_device *dev, __u8 dsfield,
711 			       struct flowi6 *fl6, int encap_limit,
712 			       __u32 *pmtu, __be16 proto)
713 {
714 	struct ip6_tnl *tunnel = netdev_priv(dev);
715 	__be16 protocol;
716 
717 	if (dev->type == ARPHRD_ETHER)
718 		IPCB(skb)->flags = 0;
719 
720 	if (dev->header_ops && dev->type == ARPHRD_IP6GRE)
721 		fl6->daddr = ((struct ipv6hdr *)skb->data)->daddr;
722 	else
723 		fl6->daddr = tunnel->parms.raddr;
724 
725 	if (skb_cow_head(skb, dev->needed_headroom ?: tunnel->hlen))
726 		return -ENOMEM;
727 
728 	/* Push GRE header. */
729 	protocol = (dev->type == ARPHRD_ETHER) ? htons(ETH_P_TEB) : proto;
730 
731 	if (tunnel->parms.collect_md) {
732 		struct ip_tunnel_info *tun_info;
733 		const struct ip_tunnel_key *key;
734 		__be16 flags;
735 
736 		tun_info = skb_tunnel_info(skb);
737 		if (unlikely(!tun_info ||
738 			     !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
739 			     ip_tunnel_info_af(tun_info) != AF_INET6))
740 			return -EINVAL;
741 
742 		key = &tun_info->key;
743 		memset(fl6, 0, sizeof(*fl6));
744 		fl6->flowi6_proto = IPPROTO_GRE;
745 		fl6->daddr = key->u.ipv6.dst;
746 		fl6->flowlabel = key->label;
747 		fl6->flowi6_uid = sock_net_uid(dev_net(dev), NULL);
748 
749 		dsfield = key->tos;
750 		flags = key->tun_flags &
751 			(TUNNEL_CSUM | TUNNEL_KEY | TUNNEL_SEQ);
752 		tunnel->tun_hlen = gre_calc_hlen(flags);
753 
754 		gre_build_header(skb, tunnel->tun_hlen,
755 				 flags, protocol,
756 				 tunnel_id_to_key32(tun_info->key.tun_id),
757 				 (flags & TUNNEL_SEQ) ? htonl(tunnel->o_seqno++)
758 						      : 0);
759 
760 	} else {
761 		if (tunnel->parms.o_flags & TUNNEL_SEQ)
762 			tunnel->o_seqno++;
763 
764 		gre_build_header(skb, tunnel->tun_hlen, tunnel->parms.o_flags,
765 				 protocol, tunnel->parms.o_key,
766 				 htonl(tunnel->o_seqno));
767 	}
768 
769 	return ip6_tnl_xmit(skb, dev, dsfield, fl6, encap_limit, pmtu,
770 			    NEXTHDR_GRE);
771 }
772 
773 static inline int ip6gre_xmit_ipv4(struct sk_buff *skb, struct net_device *dev)
774 {
775 	struct ip6_tnl *t = netdev_priv(dev);
776 	int encap_limit = -1;
777 	struct flowi6 fl6;
778 	__u8 dsfield = 0;
779 	__u32 mtu;
780 	int err;
781 
782 	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
783 
784 	if (!t->parms.collect_md)
785 		prepare_ip6gre_xmit_ipv4(skb, dev, &fl6,
786 					 &dsfield, &encap_limit);
787 
788 	err = gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM));
789 	if (err)
790 		return -1;
791 
792 	err = __gre6_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
793 			  skb->protocol);
794 	if (err != 0) {
795 		/* XXX: send ICMP error even if DF is not set. */
796 		if (err == -EMSGSIZE)
797 			icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
798 				  htonl(mtu));
799 		return -1;
800 	}
801 
802 	return 0;
803 }
804 
805 static inline int ip6gre_xmit_ipv6(struct sk_buff *skb, struct net_device *dev)
806 {
807 	struct ip6_tnl *t = netdev_priv(dev);
808 	struct ipv6hdr *ipv6h = ipv6_hdr(skb);
809 	int encap_limit = -1;
810 	struct flowi6 fl6;
811 	__u8 dsfield = 0;
812 	__u32 mtu;
813 	int err;
814 
815 	if (ipv6_addr_equal(&t->parms.raddr, &ipv6h->saddr))
816 		return -1;
817 
818 	if (!t->parms.collect_md &&
819 	    prepare_ip6gre_xmit_ipv6(skb, dev, &fl6, &dsfield, &encap_limit))
820 		return -1;
821 
822 	if (gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM)))
823 		return -1;
824 
825 	err = __gre6_xmit(skb, dev, dsfield, &fl6, encap_limit,
826 			  &mtu, skb->protocol);
827 	if (err != 0) {
828 		if (err == -EMSGSIZE)
829 			icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
830 		return -1;
831 	}
832 
833 	return 0;
834 }
835 
836 /**
837  * ip6gre_tnl_addr_conflict - compare packet addresses to tunnel's own
838  *   @t: the outgoing tunnel device
839  *   @hdr: IPv6 header from the incoming packet
840  *
841  * Description:
842  *   Avoid trivial tunneling loop by checking that tunnel exit-point
843  *   doesn't match source of incoming packet.
844  *
845  * Return:
846  *   1 if conflict,
847  *   0 else
848  **/
849 
850 static inline bool ip6gre_tnl_addr_conflict(const struct ip6_tnl *t,
851 	const struct ipv6hdr *hdr)
852 {
853 	return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
854 }
855 
856 static int ip6gre_xmit_other(struct sk_buff *skb, struct net_device *dev)
857 {
858 	struct ip6_tnl *t = netdev_priv(dev);
859 	int encap_limit = -1;
860 	struct flowi6 fl6;
861 	__u32 mtu;
862 	int err;
863 
864 	if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
865 		encap_limit = t->parms.encap_limit;
866 
867 	if (!t->parms.collect_md)
868 		memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
869 
870 	err = gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM));
871 	if (err)
872 		return err;
873 
874 	err = __gre6_xmit(skb, dev, 0, &fl6, encap_limit, &mtu, skb->protocol);
875 
876 	return err;
877 }
878 
879 static netdev_tx_t ip6gre_tunnel_xmit(struct sk_buff *skb,
880 	struct net_device *dev)
881 {
882 	struct ip6_tnl *t = netdev_priv(dev);
883 	struct net_device_stats *stats = &t->dev->stats;
884 	int ret;
885 
886 	if (!pskb_inet_may_pull(skb))
887 		goto tx_err;
888 
889 	if (!ip6_tnl_xmit_ctl(t, &t->parms.laddr, &t->parms.raddr))
890 		goto tx_err;
891 
892 	switch (skb->protocol) {
893 	case htons(ETH_P_IP):
894 		ret = ip6gre_xmit_ipv4(skb, dev);
895 		break;
896 	case htons(ETH_P_IPV6):
897 		ret = ip6gre_xmit_ipv6(skb, dev);
898 		break;
899 	default:
900 		ret = ip6gre_xmit_other(skb, dev);
901 		break;
902 	}
903 
904 	if (ret < 0)
905 		goto tx_err;
906 
907 	return NETDEV_TX_OK;
908 
909 tx_err:
910 	stats->tx_errors++;
911 	stats->tx_dropped++;
912 	kfree_skb(skb);
913 	return NETDEV_TX_OK;
914 }
915 
916 static netdev_tx_t ip6erspan_tunnel_xmit(struct sk_buff *skb,
917 					 struct net_device *dev)
918 {
919 	struct ip6_tnl *t = netdev_priv(dev);
920 	struct dst_entry *dst = skb_dst(skb);
921 	struct net_device_stats *stats;
922 	bool truncate = false;
923 	int encap_limit = -1;
924 	__u8 dsfield = false;
925 	struct flowi6 fl6;
926 	int err = -EINVAL;
927 	__be16 proto;
928 	__u32 mtu;
929 	int nhoff;
930 	int thoff;
931 
932 	if (!pskb_inet_may_pull(skb))
933 		goto tx_err;
934 
935 	if (!ip6_tnl_xmit_ctl(t, &t->parms.laddr, &t->parms.raddr))
936 		goto tx_err;
937 
938 	if (gre_handle_offloads(skb, false))
939 		goto tx_err;
940 
941 	if (skb->len > dev->mtu + dev->hard_header_len) {
942 		pskb_trim(skb, dev->mtu + dev->hard_header_len);
943 		truncate = true;
944 	}
945 
946 	nhoff = skb_network_header(skb) - skb_mac_header(skb);
947 	if (skb->protocol == htons(ETH_P_IP) &&
948 	    (ntohs(ip_hdr(skb)->tot_len) > skb->len - nhoff))
949 		truncate = true;
950 
951 	thoff = skb_transport_header(skb) - skb_mac_header(skb);
952 	if (skb->protocol == htons(ETH_P_IPV6) &&
953 	    (ntohs(ipv6_hdr(skb)->payload_len) > skb->len - thoff))
954 		truncate = true;
955 
956 	if (skb_cow_head(skb, dev->needed_headroom ?: t->hlen))
957 		goto tx_err;
958 
959 	t->parms.o_flags &= ~TUNNEL_KEY;
960 	IPCB(skb)->flags = 0;
961 
962 	/* For collect_md mode, derive fl6 from the tunnel key,
963 	 * for native mode, call prepare_ip6gre_xmit_{ipv4,ipv6}.
964 	 */
965 	if (t->parms.collect_md) {
966 		struct ip_tunnel_info *tun_info;
967 		const struct ip_tunnel_key *key;
968 		struct erspan_metadata *md;
969 		__be32 tun_id;
970 
971 		tun_info = skb_tunnel_info(skb);
972 		if (unlikely(!tun_info ||
973 			     !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
974 			     ip_tunnel_info_af(tun_info) != AF_INET6))
975 			return -EINVAL;
976 
977 		key = &tun_info->key;
978 		memset(&fl6, 0, sizeof(fl6));
979 		fl6.flowi6_proto = IPPROTO_GRE;
980 		fl6.daddr = key->u.ipv6.dst;
981 		fl6.flowlabel = key->label;
982 		fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
983 
984 		dsfield = key->tos;
985 		if (!(tun_info->key.tun_flags & TUNNEL_ERSPAN_OPT))
986 			goto tx_err;
987 		md = ip_tunnel_info_opts(tun_info);
988 		if (!md)
989 			goto tx_err;
990 
991 		tun_id = tunnel_id_to_key32(key->tun_id);
992 		if (md->version == 1) {
993 			erspan_build_header(skb,
994 					    ntohl(tun_id),
995 					    ntohl(md->u.index), truncate,
996 					    false);
997 		} else if (md->version == 2) {
998 			erspan_build_header_v2(skb,
999 					       ntohl(tun_id),
1000 					       md->u.md2.dir,
1001 					       get_hwid(&md->u.md2),
1002 					       truncate, false);
1003 		} else {
1004 			goto tx_err;
1005 		}
1006 	} else {
1007 		switch (skb->protocol) {
1008 		case htons(ETH_P_IP):
1009 			memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1010 			prepare_ip6gre_xmit_ipv4(skb, dev, &fl6,
1011 						 &dsfield, &encap_limit);
1012 			break;
1013 		case htons(ETH_P_IPV6):
1014 			if (ipv6_addr_equal(&t->parms.raddr, &ipv6_hdr(skb)->saddr))
1015 				goto tx_err;
1016 			if (prepare_ip6gre_xmit_ipv6(skb, dev, &fl6,
1017 						     &dsfield, &encap_limit))
1018 				goto tx_err;
1019 			break;
1020 		default:
1021 			memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
1022 			break;
1023 		}
1024 
1025 		if (t->parms.erspan_ver == 1)
1026 			erspan_build_header(skb, ntohl(t->parms.o_key),
1027 					    t->parms.index,
1028 					    truncate, false);
1029 		else if (t->parms.erspan_ver == 2)
1030 			erspan_build_header_v2(skb, ntohl(t->parms.o_key),
1031 					       t->parms.dir,
1032 					       t->parms.hwid,
1033 					       truncate, false);
1034 		else
1035 			goto tx_err;
1036 
1037 		fl6.daddr = t->parms.raddr;
1038 	}
1039 
1040 	/* Push GRE header. */
1041 	proto = (t->parms.erspan_ver == 1) ? htons(ETH_P_ERSPAN)
1042 					   : htons(ETH_P_ERSPAN2);
1043 	gre_build_header(skb, 8, TUNNEL_SEQ, proto, 0, htonl(t->o_seqno++));
1044 
1045 	/* TooBig packet may have updated dst->dev's mtu */
1046 	if (!t->parms.collect_md && dst && dst_mtu(dst) > dst->dev->mtu)
1047 		dst->ops->update_pmtu(dst, NULL, skb, dst->dev->mtu);
1048 
1049 	err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
1050 			   NEXTHDR_GRE);
1051 	if (err != 0) {
1052 		/* XXX: send ICMP error even if DF is not set. */
1053 		if (err == -EMSGSIZE) {
1054 			if (skb->protocol == htons(ETH_P_IP))
1055 				icmp_send(skb, ICMP_DEST_UNREACH,
1056 					  ICMP_FRAG_NEEDED, htonl(mtu));
1057 			else
1058 				icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
1059 		}
1060 
1061 		goto tx_err;
1062 	}
1063 	return NETDEV_TX_OK;
1064 
1065 tx_err:
1066 	stats = &t->dev->stats;
1067 	stats->tx_errors++;
1068 	stats->tx_dropped++;
1069 	kfree_skb(skb);
1070 	return NETDEV_TX_OK;
1071 }
1072 
1073 static void ip6gre_tnl_link_config_common(struct ip6_tnl *t)
1074 {
1075 	struct net_device *dev = t->dev;
1076 	struct __ip6_tnl_parm *p = &t->parms;
1077 	struct flowi6 *fl6 = &t->fl.u.ip6;
1078 
1079 	if (dev->type != ARPHRD_ETHER) {
1080 		memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
1081 		memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
1082 	}
1083 
1084 	/* Set up flowi template */
1085 	fl6->saddr = p->laddr;
1086 	fl6->daddr = p->raddr;
1087 	fl6->flowi6_oif = p->link;
1088 	fl6->flowlabel = 0;
1089 	fl6->flowi6_proto = IPPROTO_GRE;
1090 
1091 	if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
1092 		fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
1093 	if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
1094 		fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
1095 
1096 	p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
1097 	p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
1098 
1099 	if (p->flags&IP6_TNL_F_CAP_XMIT &&
1100 			p->flags&IP6_TNL_F_CAP_RCV && dev->type != ARPHRD_ETHER)
1101 		dev->flags |= IFF_POINTOPOINT;
1102 	else
1103 		dev->flags &= ~IFF_POINTOPOINT;
1104 }
1105 
1106 static void ip6gre_tnl_link_config_route(struct ip6_tnl *t, int set_mtu,
1107 					 int t_hlen)
1108 {
1109 	const struct __ip6_tnl_parm *p = &t->parms;
1110 	struct net_device *dev = t->dev;
1111 
1112 	if (p->flags & IP6_TNL_F_CAP_XMIT) {
1113 		int strict = (ipv6_addr_type(&p->raddr) &
1114 			      (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
1115 
1116 		struct rt6_info *rt = rt6_lookup(t->net,
1117 						 &p->raddr, &p->laddr,
1118 						 p->link, NULL, strict);
1119 
1120 		if (!rt)
1121 			return;
1122 
1123 		if (rt->dst.dev) {
1124 			dev->needed_headroom = rt->dst.dev->hard_header_len +
1125 					       t_hlen;
1126 
1127 			if (set_mtu) {
1128 				dev->mtu = rt->dst.dev->mtu - t_hlen;
1129 				if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1130 					dev->mtu -= 8;
1131 				if (dev->type == ARPHRD_ETHER)
1132 					dev->mtu -= ETH_HLEN;
1133 
1134 				if (dev->mtu < IPV6_MIN_MTU)
1135 					dev->mtu = IPV6_MIN_MTU;
1136 			}
1137 		}
1138 		ip6_rt_put(rt);
1139 	}
1140 }
1141 
1142 static int ip6gre_calc_hlen(struct ip6_tnl *tunnel)
1143 {
1144 	int t_hlen;
1145 
1146 	tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags);
1147 	tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen;
1148 
1149 	t_hlen = tunnel->hlen + sizeof(struct ipv6hdr);
1150 	tunnel->dev->needed_headroom = LL_MAX_HEADER + t_hlen;
1151 	return t_hlen;
1152 }
1153 
1154 static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu)
1155 {
1156 	ip6gre_tnl_link_config_common(t);
1157 	ip6gre_tnl_link_config_route(t, set_mtu, ip6gre_calc_hlen(t));
1158 }
1159 
1160 static void ip6gre_tnl_copy_tnl_parm(struct ip6_tnl *t,
1161 				     const struct __ip6_tnl_parm *p)
1162 {
1163 	t->parms.laddr = p->laddr;
1164 	t->parms.raddr = p->raddr;
1165 	t->parms.flags = p->flags;
1166 	t->parms.hop_limit = p->hop_limit;
1167 	t->parms.encap_limit = p->encap_limit;
1168 	t->parms.flowinfo = p->flowinfo;
1169 	t->parms.link = p->link;
1170 	t->parms.proto = p->proto;
1171 	t->parms.i_key = p->i_key;
1172 	t->parms.o_key = p->o_key;
1173 	t->parms.i_flags = p->i_flags;
1174 	t->parms.o_flags = p->o_flags;
1175 	t->parms.fwmark = p->fwmark;
1176 	t->parms.erspan_ver = p->erspan_ver;
1177 	t->parms.index = p->index;
1178 	t->parms.dir = p->dir;
1179 	t->parms.hwid = p->hwid;
1180 	dst_cache_reset(&t->dst_cache);
1181 }
1182 
1183 static int ip6gre_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p,
1184 			     int set_mtu)
1185 {
1186 	ip6gre_tnl_copy_tnl_parm(t, p);
1187 	ip6gre_tnl_link_config(t, set_mtu);
1188 	return 0;
1189 }
1190 
1191 static void ip6gre_tnl_parm_from_user(struct __ip6_tnl_parm *p,
1192 	const struct ip6_tnl_parm2 *u)
1193 {
1194 	p->laddr = u->laddr;
1195 	p->raddr = u->raddr;
1196 	p->flags = u->flags;
1197 	p->hop_limit = u->hop_limit;
1198 	p->encap_limit = u->encap_limit;
1199 	p->flowinfo = u->flowinfo;
1200 	p->link = u->link;
1201 	p->i_key = u->i_key;
1202 	p->o_key = u->o_key;
1203 	p->i_flags = gre_flags_to_tnl_flags(u->i_flags);
1204 	p->o_flags = gre_flags_to_tnl_flags(u->o_flags);
1205 	memcpy(p->name, u->name, sizeof(u->name));
1206 }
1207 
1208 static void ip6gre_tnl_parm_to_user(struct ip6_tnl_parm2 *u,
1209 	const struct __ip6_tnl_parm *p)
1210 {
1211 	u->proto = IPPROTO_GRE;
1212 	u->laddr = p->laddr;
1213 	u->raddr = p->raddr;
1214 	u->flags = p->flags;
1215 	u->hop_limit = p->hop_limit;
1216 	u->encap_limit = p->encap_limit;
1217 	u->flowinfo = p->flowinfo;
1218 	u->link = p->link;
1219 	u->i_key = p->i_key;
1220 	u->o_key = p->o_key;
1221 	u->i_flags = gre_tnl_flags_to_gre_flags(p->i_flags);
1222 	u->o_flags = gre_tnl_flags_to_gre_flags(p->o_flags);
1223 	memcpy(u->name, p->name, sizeof(u->name));
1224 }
1225 
1226 static int ip6gre_tunnel_ioctl(struct net_device *dev,
1227 	struct ifreq *ifr, int cmd)
1228 {
1229 	int err = 0;
1230 	struct ip6_tnl_parm2 p;
1231 	struct __ip6_tnl_parm p1;
1232 	struct ip6_tnl *t = netdev_priv(dev);
1233 	struct net *net = t->net;
1234 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1235 
1236 	memset(&p1, 0, sizeof(p1));
1237 
1238 	switch (cmd) {
1239 	case SIOCGETTUNNEL:
1240 		if (dev == ign->fb_tunnel_dev) {
1241 			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1242 				err = -EFAULT;
1243 				break;
1244 			}
1245 			ip6gre_tnl_parm_from_user(&p1, &p);
1246 			t = ip6gre_tunnel_locate(net, &p1, 0);
1247 			if (!t)
1248 				t = netdev_priv(dev);
1249 		}
1250 		memset(&p, 0, sizeof(p));
1251 		ip6gre_tnl_parm_to_user(&p, &t->parms);
1252 		if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1253 			err = -EFAULT;
1254 		break;
1255 
1256 	case SIOCADDTUNNEL:
1257 	case SIOCCHGTUNNEL:
1258 		err = -EPERM;
1259 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1260 			goto done;
1261 
1262 		err = -EFAULT;
1263 		if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1264 			goto done;
1265 
1266 		err = -EINVAL;
1267 		if ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING))
1268 			goto done;
1269 
1270 		if (!(p.i_flags&GRE_KEY))
1271 			p.i_key = 0;
1272 		if (!(p.o_flags&GRE_KEY))
1273 			p.o_key = 0;
1274 
1275 		ip6gre_tnl_parm_from_user(&p1, &p);
1276 		t = ip6gre_tunnel_locate(net, &p1, cmd == SIOCADDTUNNEL);
1277 
1278 		if (dev != ign->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
1279 			if (t) {
1280 				if (t->dev != dev) {
1281 					err = -EEXIST;
1282 					break;
1283 				}
1284 			} else {
1285 				t = netdev_priv(dev);
1286 
1287 				ip6gre_tunnel_unlink(ign, t);
1288 				synchronize_net();
1289 				ip6gre_tnl_change(t, &p1, 1);
1290 				ip6gre_tunnel_link(ign, t);
1291 				netdev_state_change(dev);
1292 			}
1293 		}
1294 
1295 		if (t) {
1296 			err = 0;
1297 
1298 			memset(&p, 0, sizeof(p));
1299 			ip6gre_tnl_parm_to_user(&p, &t->parms);
1300 			if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1301 				err = -EFAULT;
1302 		} else
1303 			err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1304 		break;
1305 
1306 	case SIOCDELTUNNEL:
1307 		err = -EPERM;
1308 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1309 			goto done;
1310 
1311 		if (dev == ign->fb_tunnel_dev) {
1312 			err = -EFAULT;
1313 			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1314 				goto done;
1315 			err = -ENOENT;
1316 			ip6gre_tnl_parm_from_user(&p1, &p);
1317 			t = ip6gre_tunnel_locate(net, &p1, 0);
1318 			if (!t)
1319 				goto done;
1320 			err = -EPERM;
1321 			if (t == netdev_priv(ign->fb_tunnel_dev))
1322 				goto done;
1323 			dev = t->dev;
1324 		}
1325 		unregister_netdevice(dev);
1326 		err = 0;
1327 		break;
1328 
1329 	default:
1330 		err = -EINVAL;
1331 	}
1332 
1333 done:
1334 	return err;
1335 }
1336 
1337 static int ip6gre_header(struct sk_buff *skb, struct net_device *dev,
1338 			 unsigned short type, const void *daddr,
1339 			 const void *saddr, unsigned int len)
1340 {
1341 	struct ip6_tnl *t = netdev_priv(dev);
1342 	struct ipv6hdr *ipv6h;
1343 	__be16 *p;
1344 
1345 	ipv6h = skb_push(skb, t->hlen + sizeof(*ipv6h));
1346 	ip6_flow_hdr(ipv6h, 0, ip6_make_flowlabel(dev_net(dev), skb,
1347 						  t->fl.u.ip6.flowlabel,
1348 						  true, &t->fl.u.ip6));
1349 	ipv6h->hop_limit = t->parms.hop_limit;
1350 	ipv6h->nexthdr = NEXTHDR_GRE;
1351 	ipv6h->saddr = t->parms.laddr;
1352 	ipv6h->daddr = t->parms.raddr;
1353 
1354 	p = (__be16 *)(ipv6h + 1);
1355 	p[0] = t->parms.o_flags;
1356 	p[1] = htons(type);
1357 
1358 	/*
1359 	 *	Set the source hardware address.
1360 	 */
1361 
1362 	if (saddr)
1363 		memcpy(&ipv6h->saddr, saddr, sizeof(struct in6_addr));
1364 	if (daddr)
1365 		memcpy(&ipv6h->daddr, daddr, sizeof(struct in6_addr));
1366 	if (!ipv6_addr_any(&ipv6h->daddr))
1367 		return t->hlen;
1368 
1369 	return -t->hlen;
1370 }
1371 
1372 static const struct header_ops ip6gre_header_ops = {
1373 	.create	= ip6gre_header,
1374 };
1375 
1376 static const struct net_device_ops ip6gre_netdev_ops = {
1377 	.ndo_init		= ip6gre_tunnel_init,
1378 	.ndo_uninit		= ip6gre_tunnel_uninit,
1379 	.ndo_start_xmit		= ip6gre_tunnel_xmit,
1380 	.ndo_do_ioctl		= ip6gre_tunnel_ioctl,
1381 	.ndo_change_mtu		= ip6_tnl_change_mtu,
1382 	.ndo_get_stats64	= ip_tunnel_get_stats64,
1383 	.ndo_get_iflink		= ip6_tnl_get_iflink,
1384 };
1385 
1386 static void ip6gre_dev_free(struct net_device *dev)
1387 {
1388 	struct ip6_tnl *t = netdev_priv(dev);
1389 
1390 	gro_cells_destroy(&t->gro_cells);
1391 	dst_cache_destroy(&t->dst_cache);
1392 	free_percpu(dev->tstats);
1393 }
1394 
1395 static void ip6gre_tunnel_setup(struct net_device *dev)
1396 {
1397 	dev->netdev_ops = &ip6gre_netdev_ops;
1398 	dev->needs_free_netdev = true;
1399 	dev->priv_destructor = ip6gre_dev_free;
1400 
1401 	dev->type = ARPHRD_IP6GRE;
1402 
1403 	dev->flags |= IFF_NOARP;
1404 	dev->addr_len = sizeof(struct in6_addr);
1405 	netif_keep_dst(dev);
1406 	/* This perm addr will be used as interface identifier by IPv6 */
1407 	dev->addr_assign_type = NET_ADDR_RANDOM;
1408 	eth_random_addr(dev->perm_addr);
1409 }
1410 
1411 #define GRE6_FEATURES (NETIF_F_SG |		\
1412 		       NETIF_F_FRAGLIST |	\
1413 		       NETIF_F_HIGHDMA |	\
1414 		       NETIF_F_HW_CSUM)
1415 
1416 static void ip6gre_tnl_init_features(struct net_device *dev)
1417 {
1418 	struct ip6_tnl *nt = netdev_priv(dev);
1419 
1420 	dev->features		|= GRE6_FEATURES;
1421 	dev->hw_features	|= GRE6_FEATURES;
1422 
1423 	if (!(nt->parms.o_flags & TUNNEL_SEQ)) {
1424 		/* TCP offload with GRE SEQ is not supported, nor
1425 		 * can we support 2 levels of outer headers requiring
1426 		 * an update.
1427 		 */
1428 		if (!(nt->parms.o_flags & TUNNEL_CSUM) ||
1429 		    nt->encap.type == TUNNEL_ENCAP_NONE) {
1430 			dev->features    |= NETIF_F_GSO_SOFTWARE;
1431 			dev->hw_features |= NETIF_F_GSO_SOFTWARE;
1432 		}
1433 
1434 		/* Can use a lockless transmit, unless we generate
1435 		 * output sequences
1436 		 */
1437 		dev->features |= NETIF_F_LLTX;
1438 	}
1439 }
1440 
1441 static int ip6gre_tunnel_init_common(struct net_device *dev)
1442 {
1443 	struct ip6_tnl *tunnel;
1444 	int ret;
1445 	int t_hlen;
1446 
1447 	tunnel = netdev_priv(dev);
1448 
1449 	tunnel->dev = dev;
1450 	tunnel->net = dev_net(dev);
1451 	strcpy(tunnel->parms.name, dev->name);
1452 
1453 	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1454 	if (!dev->tstats)
1455 		return -ENOMEM;
1456 
1457 	ret = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL);
1458 	if (ret)
1459 		goto cleanup_alloc_pcpu_stats;
1460 
1461 	ret = gro_cells_init(&tunnel->gro_cells, dev);
1462 	if (ret)
1463 		goto cleanup_dst_cache_init;
1464 
1465 	t_hlen = ip6gre_calc_hlen(tunnel);
1466 	dev->mtu = ETH_DATA_LEN - t_hlen;
1467 	if (dev->type == ARPHRD_ETHER)
1468 		dev->mtu -= ETH_HLEN;
1469 	if (!(tunnel->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1470 		dev->mtu -= 8;
1471 
1472 	if (tunnel->parms.collect_md) {
1473 		dev->features |= NETIF_F_NETNS_LOCAL;
1474 		netif_keep_dst(dev);
1475 	}
1476 	ip6gre_tnl_init_features(dev);
1477 
1478 	return 0;
1479 
1480 cleanup_dst_cache_init:
1481 	dst_cache_destroy(&tunnel->dst_cache);
1482 cleanup_alloc_pcpu_stats:
1483 	free_percpu(dev->tstats);
1484 	dev->tstats = NULL;
1485 	return ret;
1486 }
1487 
1488 static int ip6gre_tunnel_init(struct net_device *dev)
1489 {
1490 	struct ip6_tnl *tunnel;
1491 	int ret;
1492 
1493 	ret = ip6gre_tunnel_init_common(dev);
1494 	if (ret)
1495 		return ret;
1496 
1497 	tunnel = netdev_priv(dev);
1498 
1499 	if (tunnel->parms.collect_md)
1500 		return 0;
1501 
1502 	memcpy(dev->dev_addr, &tunnel->parms.laddr, sizeof(struct in6_addr));
1503 	memcpy(dev->broadcast, &tunnel->parms.raddr, sizeof(struct in6_addr));
1504 
1505 	if (ipv6_addr_any(&tunnel->parms.raddr))
1506 		dev->header_ops = &ip6gre_header_ops;
1507 
1508 	return 0;
1509 }
1510 
1511 static void ip6gre_fb_tunnel_init(struct net_device *dev)
1512 {
1513 	struct ip6_tnl *tunnel = netdev_priv(dev);
1514 
1515 	tunnel->dev = dev;
1516 	tunnel->net = dev_net(dev);
1517 	strcpy(tunnel->parms.name, dev->name);
1518 
1519 	tunnel->hlen		= sizeof(struct ipv6hdr) + 4;
1520 
1521 	dev_hold(dev);
1522 }
1523 
1524 static struct inet6_protocol ip6gre_protocol __read_mostly = {
1525 	.handler     = gre_rcv,
1526 	.err_handler = ip6gre_err,
1527 	.flags       = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1528 };
1529 
1530 static void ip6gre_destroy_tunnels(struct net *net, struct list_head *head)
1531 {
1532 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1533 	struct net_device *dev, *aux;
1534 	int prio;
1535 
1536 	for_each_netdev_safe(net, dev, aux)
1537 		if (dev->rtnl_link_ops == &ip6gre_link_ops ||
1538 		    dev->rtnl_link_ops == &ip6gre_tap_ops ||
1539 		    dev->rtnl_link_ops == &ip6erspan_tap_ops)
1540 			unregister_netdevice_queue(dev, head);
1541 
1542 	for (prio = 0; prio < 4; prio++) {
1543 		int h;
1544 		for (h = 0; h < IP6_GRE_HASH_SIZE; h++) {
1545 			struct ip6_tnl *t;
1546 
1547 			t = rtnl_dereference(ign->tunnels[prio][h]);
1548 
1549 			while (t) {
1550 				/* If dev is in the same netns, it has already
1551 				 * been added to the list by the previous loop.
1552 				 */
1553 				if (!net_eq(dev_net(t->dev), net))
1554 					unregister_netdevice_queue(t->dev,
1555 								   head);
1556 				t = rtnl_dereference(t->next);
1557 			}
1558 		}
1559 	}
1560 }
1561 
1562 static int __net_init ip6gre_init_net(struct net *net)
1563 {
1564 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1565 	int err;
1566 
1567 	if (!net_has_fallback_tunnels(net))
1568 		return 0;
1569 	ign->fb_tunnel_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6gre0",
1570 					  NET_NAME_UNKNOWN,
1571 					  ip6gre_tunnel_setup);
1572 	if (!ign->fb_tunnel_dev) {
1573 		err = -ENOMEM;
1574 		goto err_alloc_dev;
1575 	}
1576 	dev_net_set(ign->fb_tunnel_dev, net);
1577 	/* FB netdevice is special: we have one, and only one per netns.
1578 	 * Allowing to move it to another netns is clearly unsafe.
1579 	 */
1580 	ign->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
1581 
1582 
1583 	ip6gre_fb_tunnel_init(ign->fb_tunnel_dev);
1584 	ign->fb_tunnel_dev->rtnl_link_ops = &ip6gre_link_ops;
1585 
1586 	err = register_netdev(ign->fb_tunnel_dev);
1587 	if (err)
1588 		goto err_reg_dev;
1589 
1590 	rcu_assign_pointer(ign->tunnels_wc[0],
1591 			   netdev_priv(ign->fb_tunnel_dev));
1592 	return 0;
1593 
1594 err_reg_dev:
1595 	free_netdev(ign->fb_tunnel_dev);
1596 err_alloc_dev:
1597 	return err;
1598 }
1599 
1600 static void __net_exit ip6gre_exit_batch_net(struct list_head *net_list)
1601 {
1602 	struct net *net;
1603 	LIST_HEAD(list);
1604 
1605 	rtnl_lock();
1606 	list_for_each_entry(net, net_list, exit_list)
1607 		ip6gre_destroy_tunnels(net, &list);
1608 	unregister_netdevice_many(&list);
1609 	rtnl_unlock();
1610 }
1611 
1612 static struct pernet_operations ip6gre_net_ops = {
1613 	.init = ip6gre_init_net,
1614 	.exit_batch = ip6gre_exit_batch_net,
1615 	.id   = &ip6gre_net_id,
1616 	.size = sizeof(struct ip6gre_net),
1617 };
1618 
1619 static int ip6gre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[],
1620 				  struct netlink_ext_ack *extack)
1621 {
1622 	__be16 flags;
1623 
1624 	if (!data)
1625 		return 0;
1626 
1627 	flags = 0;
1628 	if (data[IFLA_GRE_IFLAGS])
1629 		flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1630 	if (data[IFLA_GRE_OFLAGS])
1631 		flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1632 	if (flags & (GRE_VERSION|GRE_ROUTING))
1633 		return -EINVAL;
1634 
1635 	return 0;
1636 }
1637 
1638 static int ip6gre_tap_validate(struct nlattr *tb[], struct nlattr *data[],
1639 			       struct netlink_ext_ack *extack)
1640 {
1641 	struct in6_addr daddr;
1642 
1643 	if (tb[IFLA_ADDRESS]) {
1644 		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1645 			return -EINVAL;
1646 		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1647 			return -EADDRNOTAVAIL;
1648 	}
1649 
1650 	if (!data)
1651 		goto out;
1652 
1653 	if (data[IFLA_GRE_REMOTE]) {
1654 		daddr = nla_get_in6_addr(data[IFLA_GRE_REMOTE]);
1655 		if (ipv6_addr_any(&daddr))
1656 			return -EINVAL;
1657 	}
1658 
1659 out:
1660 	return ip6gre_tunnel_validate(tb, data, extack);
1661 }
1662 
1663 static int ip6erspan_tap_validate(struct nlattr *tb[], struct nlattr *data[],
1664 				  struct netlink_ext_ack *extack)
1665 {
1666 	__be16 flags = 0;
1667 	int ret, ver = 0;
1668 
1669 	if (!data)
1670 		return 0;
1671 
1672 	ret = ip6gre_tap_validate(tb, data, extack);
1673 	if (ret)
1674 		return ret;
1675 
1676 	/* ERSPAN should only have GRE sequence and key flag */
1677 	if (data[IFLA_GRE_OFLAGS])
1678 		flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1679 	if (data[IFLA_GRE_IFLAGS])
1680 		flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1681 	if (!data[IFLA_GRE_COLLECT_METADATA] &&
1682 	    flags != (GRE_SEQ | GRE_KEY))
1683 		return -EINVAL;
1684 
1685 	/* ERSPAN Session ID only has 10-bit. Since we reuse
1686 	 * 32-bit key field as ID, check it's range.
1687 	 */
1688 	if (data[IFLA_GRE_IKEY] &&
1689 	    (ntohl(nla_get_be32(data[IFLA_GRE_IKEY])) & ~ID_MASK))
1690 		return -EINVAL;
1691 
1692 	if (data[IFLA_GRE_OKEY] &&
1693 	    (ntohl(nla_get_be32(data[IFLA_GRE_OKEY])) & ~ID_MASK))
1694 		return -EINVAL;
1695 
1696 	if (data[IFLA_GRE_ERSPAN_VER]) {
1697 		ver = nla_get_u8(data[IFLA_GRE_ERSPAN_VER]);
1698 		if (ver != 1 && ver != 2)
1699 			return -EINVAL;
1700 	}
1701 
1702 	if (ver == 1) {
1703 		if (data[IFLA_GRE_ERSPAN_INDEX]) {
1704 			u32 index = nla_get_u32(data[IFLA_GRE_ERSPAN_INDEX]);
1705 
1706 			if (index & ~INDEX_MASK)
1707 				return -EINVAL;
1708 		}
1709 	} else if (ver == 2) {
1710 		if (data[IFLA_GRE_ERSPAN_DIR]) {
1711 			u16 dir = nla_get_u8(data[IFLA_GRE_ERSPAN_DIR]);
1712 
1713 			if (dir & ~(DIR_MASK >> DIR_OFFSET))
1714 				return -EINVAL;
1715 		}
1716 
1717 		if (data[IFLA_GRE_ERSPAN_HWID]) {
1718 			u16 hwid = nla_get_u16(data[IFLA_GRE_ERSPAN_HWID]);
1719 
1720 			if (hwid & ~(HWID_MASK >> HWID_OFFSET))
1721 				return -EINVAL;
1722 		}
1723 	}
1724 
1725 	return 0;
1726 }
1727 
1728 static void ip6erspan_set_version(struct nlattr *data[],
1729 				  struct __ip6_tnl_parm *parms)
1730 {
1731 	if (!data)
1732 		return;
1733 
1734 	parms->erspan_ver = 1;
1735 	if (data[IFLA_GRE_ERSPAN_VER])
1736 		parms->erspan_ver = nla_get_u8(data[IFLA_GRE_ERSPAN_VER]);
1737 
1738 	if (parms->erspan_ver == 1) {
1739 		if (data[IFLA_GRE_ERSPAN_INDEX])
1740 			parms->index = nla_get_u32(data[IFLA_GRE_ERSPAN_INDEX]);
1741 	} else if (parms->erspan_ver == 2) {
1742 		if (data[IFLA_GRE_ERSPAN_DIR])
1743 			parms->dir = nla_get_u8(data[IFLA_GRE_ERSPAN_DIR]);
1744 		if (data[IFLA_GRE_ERSPAN_HWID])
1745 			parms->hwid = nla_get_u16(data[IFLA_GRE_ERSPAN_HWID]);
1746 	}
1747 }
1748 
1749 static void ip6gre_netlink_parms(struct nlattr *data[],
1750 				struct __ip6_tnl_parm *parms)
1751 {
1752 	memset(parms, 0, sizeof(*parms));
1753 
1754 	if (!data)
1755 		return;
1756 
1757 	if (data[IFLA_GRE_LINK])
1758 		parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
1759 
1760 	if (data[IFLA_GRE_IFLAGS])
1761 		parms->i_flags = gre_flags_to_tnl_flags(
1762 				nla_get_be16(data[IFLA_GRE_IFLAGS]));
1763 
1764 	if (data[IFLA_GRE_OFLAGS])
1765 		parms->o_flags = gre_flags_to_tnl_flags(
1766 				nla_get_be16(data[IFLA_GRE_OFLAGS]));
1767 
1768 	if (data[IFLA_GRE_IKEY])
1769 		parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
1770 
1771 	if (data[IFLA_GRE_OKEY])
1772 		parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
1773 
1774 	if (data[IFLA_GRE_LOCAL])
1775 		parms->laddr = nla_get_in6_addr(data[IFLA_GRE_LOCAL]);
1776 
1777 	if (data[IFLA_GRE_REMOTE])
1778 		parms->raddr = nla_get_in6_addr(data[IFLA_GRE_REMOTE]);
1779 
1780 	if (data[IFLA_GRE_TTL])
1781 		parms->hop_limit = nla_get_u8(data[IFLA_GRE_TTL]);
1782 
1783 	if (data[IFLA_GRE_ENCAP_LIMIT])
1784 		parms->encap_limit = nla_get_u8(data[IFLA_GRE_ENCAP_LIMIT]);
1785 
1786 	if (data[IFLA_GRE_FLOWINFO])
1787 		parms->flowinfo = nla_get_be32(data[IFLA_GRE_FLOWINFO]);
1788 
1789 	if (data[IFLA_GRE_FLAGS])
1790 		parms->flags = nla_get_u32(data[IFLA_GRE_FLAGS]);
1791 
1792 	if (data[IFLA_GRE_FWMARK])
1793 		parms->fwmark = nla_get_u32(data[IFLA_GRE_FWMARK]);
1794 
1795 	if (data[IFLA_GRE_COLLECT_METADATA])
1796 		parms->collect_md = true;
1797 }
1798 
1799 static int ip6gre_tap_init(struct net_device *dev)
1800 {
1801 	int ret;
1802 
1803 	ret = ip6gre_tunnel_init_common(dev);
1804 	if (ret)
1805 		return ret;
1806 
1807 	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1808 
1809 	return 0;
1810 }
1811 
1812 static const struct net_device_ops ip6gre_tap_netdev_ops = {
1813 	.ndo_init = ip6gre_tap_init,
1814 	.ndo_uninit = ip6gre_tunnel_uninit,
1815 	.ndo_start_xmit = ip6gre_tunnel_xmit,
1816 	.ndo_set_mac_address = eth_mac_addr,
1817 	.ndo_validate_addr = eth_validate_addr,
1818 	.ndo_change_mtu = ip6_tnl_change_mtu,
1819 	.ndo_get_stats64 = ip_tunnel_get_stats64,
1820 	.ndo_get_iflink = ip6_tnl_get_iflink,
1821 };
1822 
1823 static int ip6erspan_calc_hlen(struct ip6_tnl *tunnel)
1824 {
1825 	int t_hlen;
1826 
1827 	tunnel->tun_hlen = 8;
1828 	tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen +
1829 		       erspan_hdr_len(tunnel->parms.erspan_ver);
1830 
1831 	t_hlen = tunnel->hlen + sizeof(struct ipv6hdr);
1832 	tunnel->dev->needed_headroom = LL_MAX_HEADER + t_hlen;
1833 	return t_hlen;
1834 }
1835 
1836 static int ip6erspan_tap_init(struct net_device *dev)
1837 {
1838 	struct ip6_tnl *tunnel;
1839 	int t_hlen;
1840 	int ret;
1841 
1842 	tunnel = netdev_priv(dev);
1843 
1844 	tunnel->dev = dev;
1845 	tunnel->net = dev_net(dev);
1846 	strcpy(tunnel->parms.name, dev->name);
1847 
1848 	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1849 	if (!dev->tstats)
1850 		return -ENOMEM;
1851 
1852 	ret = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL);
1853 	if (ret)
1854 		goto cleanup_alloc_pcpu_stats;
1855 
1856 	ret = gro_cells_init(&tunnel->gro_cells, dev);
1857 	if (ret)
1858 		goto cleanup_dst_cache_init;
1859 
1860 	t_hlen = ip6erspan_calc_hlen(tunnel);
1861 	dev->mtu = ETH_DATA_LEN - t_hlen;
1862 	if (dev->type == ARPHRD_ETHER)
1863 		dev->mtu -= ETH_HLEN;
1864 	if (!(tunnel->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1865 		dev->mtu -= 8;
1866 
1867 	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1868 	ip6erspan_tnl_link_config(tunnel, 1);
1869 
1870 	return 0;
1871 
1872 cleanup_dst_cache_init:
1873 	dst_cache_destroy(&tunnel->dst_cache);
1874 cleanup_alloc_pcpu_stats:
1875 	free_percpu(dev->tstats);
1876 	dev->tstats = NULL;
1877 	return ret;
1878 }
1879 
1880 static const struct net_device_ops ip6erspan_netdev_ops = {
1881 	.ndo_init =		ip6erspan_tap_init,
1882 	.ndo_uninit =		ip6erspan_tunnel_uninit,
1883 	.ndo_start_xmit =	ip6erspan_tunnel_xmit,
1884 	.ndo_set_mac_address =	eth_mac_addr,
1885 	.ndo_validate_addr =	eth_validate_addr,
1886 	.ndo_change_mtu =	ip6_tnl_change_mtu,
1887 	.ndo_get_stats64 =	ip_tunnel_get_stats64,
1888 	.ndo_get_iflink =	ip6_tnl_get_iflink,
1889 };
1890 
1891 static void ip6gre_tap_setup(struct net_device *dev)
1892 {
1893 
1894 	ether_setup(dev);
1895 
1896 	dev->max_mtu = 0;
1897 	dev->netdev_ops = &ip6gre_tap_netdev_ops;
1898 	dev->needs_free_netdev = true;
1899 	dev->priv_destructor = ip6gre_dev_free;
1900 
1901 	dev->features |= NETIF_F_NETNS_LOCAL;
1902 	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1903 	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1904 	netif_keep_dst(dev);
1905 }
1906 
1907 static bool ip6gre_netlink_encap_parms(struct nlattr *data[],
1908 				       struct ip_tunnel_encap *ipencap)
1909 {
1910 	bool ret = false;
1911 
1912 	memset(ipencap, 0, sizeof(*ipencap));
1913 
1914 	if (!data)
1915 		return ret;
1916 
1917 	if (data[IFLA_GRE_ENCAP_TYPE]) {
1918 		ret = true;
1919 		ipencap->type = nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]);
1920 	}
1921 
1922 	if (data[IFLA_GRE_ENCAP_FLAGS]) {
1923 		ret = true;
1924 		ipencap->flags = nla_get_u16(data[IFLA_GRE_ENCAP_FLAGS]);
1925 	}
1926 
1927 	if (data[IFLA_GRE_ENCAP_SPORT]) {
1928 		ret = true;
1929 		ipencap->sport = nla_get_be16(data[IFLA_GRE_ENCAP_SPORT]);
1930 	}
1931 
1932 	if (data[IFLA_GRE_ENCAP_DPORT]) {
1933 		ret = true;
1934 		ipencap->dport = nla_get_be16(data[IFLA_GRE_ENCAP_DPORT]);
1935 	}
1936 
1937 	return ret;
1938 }
1939 
1940 static int ip6gre_newlink_common(struct net *src_net, struct net_device *dev,
1941 				 struct nlattr *tb[], struct nlattr *data[],
1942 				 struct netlink_ext_ack *extack)
1943 {
1944 	struct ip6_tnl *nt;
1945 	struct ip_tunnel_encap ipencap;
1946 	int err;
1947 
1948 	nt = netdev_priv(dev);
1949 
1950 	if (ip6gre_netlink_encap_parms(data, &ipencap)) {
1951 		int err = ip6_tnl_encap_setup(nt, &ipencap);
1952 
1953 		if (err < 0)
1954 			return err;
1955 	}
1956 
1957 	if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
1958 		eth_hw_addr_random(dev);
1959 
1960 	nt->dev = dev;
1961 	nt->net = dev_net(dev);
1962 
1963 	err = register_netdevice(dev);
1964 	if (err)
1965 		goto out;
1966 
1967 	if (tb[IFLA_MTU])
1968 		ip6_tnl_change_mtu(dev, nla_get_u32(tb[IFLA_MTU]));
1969 
1970 	dev_hold(dev);
1971 
1972 out:
1973 	return err;
1974 }
1975 
1976 static int ip6gre_newlink(struct net *src_net, struct net_device *dev,
1977 			  struct nlattr *tb[], struct nlattr *data[],
1978 			  struct netlink_ext_ack *extack)
1979 {
1980 	struct ip6_tnl *nt = netdev_priv(dev);
1981 	struct net *net = dev_net(dev);
1982 	struct ip6gre_net *ign;
1983 	int err;
1984 
1985 	ip6gre_netlink_parms(data, &nt->parms);
1986 	ign = net_generic(net, ip6gre_net_id);
1987 
1988 	if (nt->parms.collect_md) {
1989 		if (rtnl_dereference(ign->collect_md_tun))
1990 			return -EEXIST;
1991 	} else {
1992 		if (ip6gre_tunnel_find(net, &nt->parms, dev->type))
1993 			return -EEXIST;
1994 	}
1995 
1996 	err = ip6gre_newlink_common(src_net, dev, tb, data, extack);
1997 	if (!err) {
1998 		ip6gre_tnl_link_config(nt, !tb[IFLA_MTU]);
1999 		ip6gre_tunnel_link_md(ign, nt);
2000 		ip6gre_tunnel_link(net_generic(net, ip6gre_net_id), nt);
2001 	}
2002 	return err;
2003 }
2004 
2005 static struct ip6_tnl *
2006 ip6gre_changelink_common(struct net_device *dev, struct nlattr *tb[],
2007 			 struct nlattr *data[], struct __ip6_tnl_parm *p_p,
2008 			 struct netlink_ext_ack *extack)
2009 {
2010 	struct ip6_tnl *t, *nt = netdev_priv(dev);
2011 	struct net *net = nt->net;
2012 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
2013 	struct ip_tunnel_encap ipencap;
2014 
2015 	if (dev == ign->fb_tunnel_dev)
2016 		return ERR_PTR(-EINVAL);
2017 
2018 	if (ip6gre_netlink_encap_parms(data, &ipencap)) {
2019 		int err = ip6_tnl_encap_setup(nt, &ipencap);
2020 
2021 		if (err < 0)
2022 			return ERR_PTR(err);
2023 	}
2024 
2025 	ip6gre_netlink_parms(data, p_p);
2026 
2027 	t = ip6gre_tunnel_locate(net, p_p, 0);
2028 
2029 	if (t) {
2030 		if (t->dev != dev)
2031 			return ERR_PTR(-EEXIST);
2032 	} else {
2033 		t = nt;
2034 	}
2035 
2036 	return t;
2037 }
2038 
2039 static int ip6gre_changelink(struct net_device *dev, struct nlattr *tb[],
2040 			     struct nlattr *data[],
2041 			     struct netlink_ext_ack *extack)
2042 {
2043 	struct ip6_tnl *t = netdev_priv(dev);
2044 	struct ip6gre_net *ign = net_generic(t->net, ip6gre_net_id);
2045 	struct __ip6_tnl_parm p;
2046 
2047 	t = ip6gre_changelink_common(dev, tb, data, &p, extack);
2048 	if (IS_ERR(t))
2049 		return PTR_ERR(t);
2050 
2051 	ip6gre_tunnel_unlink_md(ign, t);
2052 	ip6gre_tunnel_unlink(ign, t);
2053 	ip6gre_tnl_change(t, &p, !tb[IFLA_MTU]);
2054 	ip6gre_tunnel_link_md(ign, t);
2055 	ip6gre_tunnel_link(ign, t);
2056 	return 0;
2057 }
2058 
2059 static void ip6gre_dellink(struct net_device *dev, struct list_head *head)
2060 {
2061 	struct net *net = dev_net(dev);
2062 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
2063 
2064 	if (dev != ign->fb_tunnel_dev)
2065 		unregister_netdevice_queue(dev, head);
2066 }
2067 
2068 static size_t ip6gre_get_size(const struct net_device *dev)
2069 {
2070 	return
2071 		/* IFLA_GRE_LINK */
2072 		nla_total_size(4) +
2073 		/* IFLA_GRE_IFLAGS */
2074 		nla_total_size(2) +
2075 		/* IFLA_GRE_OFLAGS */
2076 		nla_total_size(2) +
2077 		/* IFLA_GRE_IKEY */
2078 		nla_total_size(4) +
2079 		/* IFLA_GRE_OKEY */
2080 		nla_total_size(4) +
2081 		/* IFLA_GRE_LOCAL */
2082 		nla_total_size(sizeof(struct in6_addr)) +
2083 		/* IFLA_GRE_REMOTE */
2084 		nla_total_size(sizeof(struct in6_addr)) +
2085 		/* IFLA_GRE_TTL */
2086 		nla_total_size(1) +
2087 		/* IFLA_GRE_ENCAP_LIMIT */
2088 		nla_total_size(1) +
2089 		/* IFLA_GRE_FLOWINFO */
2090 		nla_total_size(4) +
2091 		/* IFLA_GRE_FLAGS */
2092 		nla_total_size(4) +
2093 		/* IFLA_GRE_ENCAP_TYPE */
2094 		nla_total_size(2) +
2095 		/* IFLA_GRE_ENCAP_FLAGS */
2096 		nla_total_size(2) +
2097 		/* IFLA_GRE_ENCAP_SPORT */
2098 		nla_total_size(2) +
2099 		/* IFLA_GRE_ENCAP_DPORT */
2100 		nla_total_size(2) +
2101 		/* IFLA_GRE_COLLECT_METADATA */
2102 		nla_total_size(0) +
2103 		/* IFLA_GRE_FWMARK */
2104 		nla_total_size(4) +
2105 		/* IFLA_GRE_ERSPAN_INDEX */
2106 		nla_total_size(4) +
2107 		0;
2108 }
2109 
2110 static int ip6gre_fill_info(struct sk_buff *skb, const struct net_device *dev)
2111 {
2112 	struct ip6_tnl *t = netdev_priv(dev);
2113 	struct __ip6_tnl_parm *p = &t->parms;
2114 	__be16 o_flags = p->o_flags;
2115 
2116 	if (p->erspan_ver == 1 || p->erspan_ver == 2) {
2117 		if (!p->collect_md)
2118 			o_flags |= TUNNEL_KEY;
2119 
2120 		if (nla_put_u8(skb, IFLA_GRE_ERSPAN_VER, p->erspan_ver))
2121 			goto nla_put_failure;
2122 
2123 		if (p->erspan_ver == 1) {
2124 			if (nla_put_u32(skb, IFLA_GRE_ERSPAN_INDEX, p->index))
2125 				goto nla_put_failure;
2126 		} else {
2127 			if (nla_put_u8(skb, IFLA_GRE_ERSPAN_DIR, p->dir))
2128 				goto nla_put_failure;
2129 			if (nla_put_u16(skb, IFLA_GRE_ERSPAN_HWID, p->hwid))
2130 				goto nla_put_failure;
2131 		}
2132 	}
2133 
2134 	if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
2135 	    nla_put_be16(skb, IFLA_GRE_IFLAGS,
2136 			 gre_tnl_flags_to_gre_flags(p->i_flags)) ||
2137 	    nla_put_be16(skb, IFLA_GRE_OFLAGS,
2138 			 gre_tnl_flags_to_gre_flags(o_flags)) ||
2139 	    nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
2140 	    nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
2141 	    nla_put_in6_addr(skb, IFLA_GRE_LOCAL, &p->laddr) ||
2142 	    nla_put_in6_addr(skb, IFLA_GRE_REMOTE, &p->raddr) ||
2143 	    nla_put_u8(skb, IFLA_GRE_TTL, p->hop_limit) ||
2144 	    nla_put_u8(skb, IFLA_GRE_ENCAP_LIMIT, p->encap_limit) ||
2145 	    nla_put_be32(skb, IFLA_GRE_FLOWINFO, p->flowinfo) ||
2146 	    nla_put_u32(skb, IFLA_GRE_FLAGS, p->flags) ||
2147 	    nla_put_u32(skb, IFLA_GRE_FWMARK, p->fwmark))
2148 		goto nla_put_failure;
2149 
2150 	if (nla_put_u16(skb, IFLA_GRE_ENCAP_TYPE,
2151 			t->encap.type) ||
2152 	    nla_put_be16(skb, IFLA_GRE_ENCAP_SPORT,
2153 			 t->encap.sport) ||
2154 	    nla_put_be16(skb, IFLA_GRE_ENCAP_DPORT,
2155 			 t->encap.dport) ||
2156 	    nla_put_u16(skb, IFLA_GRE_ENCAP_FLAGS,
2157 			t->encap.flags))
2158 		goto nla_put_failure;
2159 
2160 	if (p->collect_md) {
2161 		if (nla_put_flag(skb, IFLA_GRE_COLLECT_METADATA))
2162 			goto nla_put_failure;
2163 	}
2164 
2165 	return 0;
2166 
2167 nla_put_failure:
2168 	return -EMSGSIZE;
2169 }
2170 
2171 static const struct nla_policy ip6gre_policy[IFLA_GRE_MAX + 1] = {
2172 	[IFLA_GRE_LINK]        = { .type = NLA_U32 },
2173 	[IFLA_GRE_IFLAGS]      = { .type = NLA_U16 },
2174 	[IFLA_GRE_OFLAGS]      = { .type = NLA_U16 },
2175 	[IFLA_GRE_IKEY]        = { .type = NLA_U32 },
2176 	[IFLA_GRE_OKEY]        = { .type = NLA_U32 },
2177 	[IFLA_GRE_LOCAL]       = { .len = FIELD_SIZEOF(struct ipv6hdr, saddr) },
2178 	[IFLA_GRE_REMOTE]      = { .len = FIELD_SIZEOF(struct ipv6hdr, daddr) },
2179 	[IFLA_GRE_TTL]         = { .type = NLA_U8 },
2180 	[IFLA_GRE_ENCAP_LIMIT] = { .type = NLA_U8 },
2181 	[IFLA_GRE_FLOWINFO]    = { .type = NLA_U32 },
2182 	[IFLA_GRE_FLAGS]       = { .type = NLA_U32 },
2183 	[IFLA_GRE_ENCAP_TYPE]   = { .type = NLA_U16 },
2184 	[IFLA_GRE_ENCAP_FLAGS]  = { .type = NLA_U16 },
2185 	[IFLA_GRE_ENCAP_SPORT]  = { .type = NLA_U16 },
2186 	[IFLA_GRE_ENCAP_DPORT]  = { .type = NLA_U16 },
2187 	[IFLA_GRE_COLLECT_METADATA] = { .type = NLA_FLAG },
2188 	[IFLA_GRE_FWMARK]       = { .type = NLA_U32 },
2189 	[IFLA_GRE_ERSPAN_INDEX] = { .type = NLA_U32 },
2190 	[IFLA_GRE_ERSPAN_VER]	= { .type = NLA_U8 },
2191 	[IFLA_GRE_ERSPAN_DIR]	= { .type = NLA_U8 },
2192 	[IFLA_GRE_ERSPAN_HWID]	= { .type = NLA_U16 },
2193 };
2194 
2195 static void ip6erspan_tap_setup(struct net_device *dev)
2196 {
2197 	ether_setup(dev);
2198 
2199 	dev->netdev_ops = &ip6erspan_netdev_ops;
2200 	dev->needs_free_netdev = true;
2201 	dev->priv_destructor = ip6gre_dev_free;
2202 
2203 	dev->features |= NETIF_F_NETNS_LOCAL;
2204 	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
2205 	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
2206 	netif_keep_dst(dev);
2207 }
2208 
2209 static int ip6erspan_newlink(struct net *src_net, struct net_device *dev,
2210 			     struct nlattr *tb[], struct nlattr *data[],
2211 			     struct netlink_ext_ack *extack)
2212 {
2213 	struct ip6_tnl *nt = netdev_priv(dev);
2214 	struct net *net = dev_net(dev);
2215 	struct ip6gre_net *ign;
2216 	int err;
2217 
2218 	ip6gre_netlink_parms(data, &nt->parms);
2219 	ip6erspan_set_version(data, &nt->parms);
2220 	ign = net_generic(net, ip6gre_net_id);
2221 
2222 	if (nt->parms.collect_md) {
2223 		if (rtnl_dereference(ign->collect_md_tun_erspan))
2224 			return -EEXIST;
2225 	} else {
2226 		if (ip6gre_tunnel_find(net, &nt->parms, dev->type))
2227 			return -EEXIST;
2228 	}
2229 
2230 	err = ip6gre_newlink_common(src_net, dev, tb, data, extack);
2231 	if (!err) {
2232 		ip6erspan_tnl_link_config(nt, !tb[IFLA_MTU]);
2233 		ip6erspan_tunnel_link_md(ign, nt);
2234 		ip6gre_tunnel_link(net_generic(net, ip6gre_net_id), nt);
2235 	}
2236 	return err;
2237 }
2238 
2239 static void ip6erspan_tnl_link_config(struct ip6_tnl *t, int set_mtu)
2240 {
2241 	ip6gre_tnl_link_config_common(t);
2242 	ip6gre_tnl_link_config_route(t, set_mtu, ip6erspan_calc_hlen(t));
2243 }
2244 
2245 static int ip6erspan_tnl_change(struct ip6_tnl *t,
2246 				const struct __ip6_tnl_parm *p, int set_mtu)
2247 {
2248 	ip6gre_tnl_copy_tnl_parm(t, p);
2249 	ip6erspan_tnl_link_config(t, set_mtu);
2250 	return 0;
2251 }
2252 
2253 static int ip6erspan_changelink(struct net_device *dev, struct nlattr *tb[],
2254 				struct nlattr *data[],
2255 				struct netlink_ext_ack *extack)
2256 {
2257 	struct ip6gre_net *ign = net_generic(dev_net(dev), ip6gre_net_id);
2258 	struct __ip6_tnl_parm p;
2259 	struct ip6_tnl *t;
2260 
2261 	t = ip6gre_changelink_common(dev, tb, data, &p, extack);
2262 	if (IS_ERR(t))
2263 		return PTR_ERR(t);
2264 
2265 	ip6erspan_set_version(data, &p);
2266 	ip6gre_tunnel_unlink_md(ign, t);
2267 	ip6gre_tunnel_unlink(ign, t);
2268 	ip6erspan_tnl_change(t, &p, !tb[IFLA_MTU]);
2269 	ip6erspan_tunnel_link_md(ign, t);
2270 	ip6gre_tunnel_link(ign, t);
2271 	return 0;
2272 }
2273 
2274 static struct rtnl_link_ops ip6gre_link_ops __read_mostly = {
2275 	.kind		= "ip6gre",
2276 	.maxtype	= IFLA_GRE_MAX,
2277 	.policy		= ip6gre_policy,
2278 	.priv_size	= sizeof(struct ip6_tnl),
2279 	.setup		= ip6gre_tunnel_setup,
2280 	.validate	= ip6gre_tunnel_validate,
2281 	.newlink	= ip6gre_newlink,
2282 	.changelink	= ip6gre_changelink,
2283 	.dellink	= ip6gre_dellink,
2284 	.get_size	= ip6gre_get_size,
2285 	.fill_info	= ip6gre_fill_info,
2286 	.get_link_net	= ip6_tnl_get_link_net,
2287 };
2288 
2289 static struct rtnl_link_ops ip6gre_tap_ops __read_mostly = {
2290 	.kind		= "ip6gretap",
2291 	.maxtype	= IFLA_GRE_MAX,
2292 	.policy		= ip6gre_policy,
2293 	.priv_size	= sizeof(struct ip6_tnl),
2294 	.setup		= ip6gre_tap_setup,
2295 	.validate	= ip6gre_tap_validate,
2296 	.newlink	= ip6gre_newlink,
2297 	.changelink	= ip6gre_changelink,
2298 	.get_size	= ip6gre_get_size,
2299 	.fill_info	= ip6gre_fill_info,
2300 	.get_link_net	= ip6_tnl_get_link_net,
2301 };
2302 
2303 static struct rtnl_link_ops ip6erspan_tap_ops __read_mostly = {
2304 	.kind		= "ip6erspan",
2305 	.maxtype	= IFLA_GRE_MAX,
2306 	.policy		= ip6gre_policy,
2307 	.priv_size	= sizeof(struct ip6_tnl),
2308 	.setup		= ip6erspan_tap_setup,
2309 	.validate	= ip6erspan_tap_validate,
2310 	.newlink	= ip6erspan_newlink,
2311 	.changelink	= ip6erspan_changelink,
2312 	.get_size	= ip6gre_get_size,
2313 	.fill_info	= ip6gre_fill_info,
2314 	.get_link_net	= ip6_tnl_get_link_net,
2315 };
2316 
2317 /*
2318  *	And now the modules code and kernel interface.
2319  */
2320 
2321 static int __init ip6gre_init(void)
2322 {
2323 	int err;
2324 
2325 	pr_info("GRE over IPv6 tunneling driver\n");
2326 
2327 	err = register_pernet_device(&ip6gre_net_ops);
2328 	if (err < 0)
2329 		return err;
2330 
2331 	err = inet6_add_protocol(&ip6gre_protocol, IPPROTO_GRE);
2332 	if (err < 0) {
2333 		pr_info("%s: can't add protocol\n", __func__);
2334 		goto add_proto_failed;
2335 	}
2336 
2337 	err = rtnl_link_register(&ip6gre_link_ops);
2338 	if (err < 0)
2339 		goto rtnl_link_failed;
2340 
2341 	err = rtnl_link_register(&ip6gre_tap_ops);
2342 	if (err < 0)
2343 		goto tap_ops_failed;
2344 
2345 	err = rtnl_link_register(&ip6erspan_tap_ops);
2346 	if (err < 0)
2347 		goto erspan_link_failed;
2348 
2349 out:
2350 	return err;
2351 
2352 erspan_link_failed:
2353 	rtnl_link_unregister(&ip6gre_tap_ops);
2354 tap_ops_failed:
2355 	rtnl_link_unregister(&ip6gre_link_ops);
2356 rtnl_link_failed:
2357 	inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
2358 add_proto_failed:
2359 	unregister_pernet_device(&ip6gre_net_ops);
2360 	goto out;
2361 }
2362 
2363 static void __exit ip6gre_fini(void)
2364 {
2365 	rtnl_link_unregister(&ip6gre_tap_ops);
2366 	rtnl_link_unregister(&ip6gre_link_ops);
2367 	rtnl_link_unregister(&ip6erspan_tap_ops);
2368 	inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
2369 	unregister_pernet_device(&ip6gre_net_ops);
2370 }
2371 
2372 module_init(ip6gre_init);
2373 module_exit(ip6gre_fini);
2374 MODULE_LICENSE("GPL");
2375 MODULE_AUTHOR("D. Kozlov (xeb@mail.ru)");
2376 MODULE_DESCRIPTION("GRE over IPv6 tunneling device");
2377 MODULE_ALIAS_RTNL_LINK("ip6gre");
2378 MODULE_ALIAS_RTNL_LINK("ip6gretap");
2379 MODULE_ALIAS_RTNL_LINK("ip6erspan");
2380 MODULE_ALIAS_NETDEV("ip6gre0");
2381