xref: /openbmc/linux/net/ipv6/ip6_gre.c (revision 6abeae2a)
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 	struct net_device *ndev;
131 
132 	for_each_ip_tunnel_rcu(t, ign->tunnels_r_l[h0 ^ h1]) {
133 		if (!ipv6_addr_equal(local, &t->parms.laddr) ||
134 		    !ipv6_addr_equal(remote, &t->parms.raddr) ||
135 		    key != t->parms.i_key ||
136 		    !(t->dev->flags & IFF_UP))
137 			continue;
138 
139 		if (t->dev->type != ARPHRD_IP6GRE &&
140 		    t->dev->type != dev_type)
141 			continue;
142 
143 		score = 0;
144 		if (t->parms.link != link)
145 			score |= 1;
146 		if (t->dev->type != dev_type)
147 			score |= 2;
148 		if (score == 0)
149 			return t;
150 
151 		if (score < cand_score) {
152 			cand = t;
153 			cand_score = score;
154 		}
155 	}
156 
157 	for_each_ip_tunnel_rcu(t, ign->tunnels_r[h0 ^ h1]) {
158 		if (!ipv6_addr_equal(remote, &t->parms.raddr) ||
159 		    key != t->parms.i_key ||
160 		    !(t->dev->flags & IFF_UP))
161 			continue;
162 
163 		if (t->dev->type != ARPHRD_IP6GRE &&
164 		    t->dev->type != dev_type)
165 			continue;
166 
167 		score = 0;
168 		if (t->parms.link != link)
169 			score |= 1;
170 		if (t->dev->type != dev_type)
171 			score |= 2;
172 		if (score == 0)
173 			return t;
174 
175 		if (score < cand_score) {
176 			cand = t;
177 			cand_score = score;
178 		}
179 	}
180 
181 	for_each_ip_tunnel_rcu(t, ign->tunnels_l[h1]) {
182 		if ((!ipv6_addr_equal(local, &t->parms.laddr) &&
183 			  (!ipv6_addr_equal(local, &t->parms.raddr) ||
184 				 !ipv6_addr_is_multicast(local))) ||
185 		    key != t->parms.i_key ||
186 		    !(t->dev->flags & IFF_UP))
187 			continue;
188 
189 		if (t->dev->type != ARPHRD_IP6GRE &&
190 		    t->dev->type != dev_type)
191 			continue;
192 
193 		score = 0;
194 		if (t->parms.link != link)
195 			score |= 1;
196 		if (t->dev->type != dev_type)
197 			score |= 2;
198 		if (score == 0)
199 			return t;
200 
201 		if (score < cand_score) {
202 			cand = t;
203 			cand_score = score;
204 		}
205 	}
206 
207 	for_each_ip_tunnel_rcu(t, ign->tunnels_wc[h1]) {
208 		if (t->parms.i_key != key ||
209 		    !(t->dev->flags & IFF_UP))
210 			continue;
211 
212 		if (t->dev->type != ARPHRD_IP6GRE &&
213 		    t->dev->type != dev_type)
214 			continue;
215 
216 		score = 0;
217 		if (t->parms.link != link)
218 			score |= 1;
219 		if (t->dev->type != dev_type)
220 			score |= 2;
221 		if (score == 0)
222 			return t;
223 
224 		if (score < cand_score) {
225 			cand = t;
226 			cand_score = score;
227 		}
228 	}
229 
230 	if (cand)
231 		return cand;
232 
233 	if (gre_proto == htons(ETH_P_ERSPAN) ||
234 	    gre_proto == htons(ETH_P_ERSPAN2))
235 		t = rcu_dereference(ign->collect_md_tun_erspan);
236 	else
237 		t = rcu_dereference(ign->collect_md_tun);
238 
239 	if (t && t->dev->flags & IFF_UP)
240 		return t;
241 
242 	ndev = READ_ONCE(ign->fb_tunnel_dev);
243 	if (ndev && ndev->flags & IFF_UP)
244 		return netdev_priv(ndev);
245 
246 	return NULL;
247 }
248 
249 static struct ip6_tnl __rcu **__ip6gre_bucket(struct ip6gre_net *ign,
250 		const struct __ip6_tnl_parm *p)
251 {
252 	const struct in6_addr *remote = &p->raddr;
253 	const struct in6_addr *local = &p->laddr;
254 	unsigned int h = HASH_KEY(p->i_key);
255 	int prio = 0;
256 
257 	if (!ipv6_addr_any(local))
258 		prio |= 1;
259 	if (!ipv6_addr_any(remote) && !ipv6_addr_is_multicast(remote)) {
260 		prio |= 2;
261 		h ^= HASH_ADDR(remote);
262 	}
263 
264 	return &ign->tunnels[prio][h];
265 }
266 
267 static void ip6gre_tunnel_link_md(struct ip6gre_net *ign, struct ip6_tnl *t)
268 {
269 	if (t->parms.collect_md)
270 		rcu_assign_pointer(ign->collect_md_tun, t);
271 }
272 
273 static void ip6erspan_tunnel_link_md(struct ip6gre_net *ign, struct ip6_tnl *t)
274 {
275 	if (t->parms.collect_md)
276 		rcu_assign_pointer(ign->collect_md_tun_erspan, t);
277 }
278 
279 static void ip6gre_tunnel_unlink_md(struct ip6gre_net *ign, struct ip6_tnl *t)
280 {
281 	if (t->parms.collect_md)
282 		rcu_assign_pointer(ign->collect_md_tun, NULL);
283 }
284 
285 static void ip6erspan_tunnel_unlink_md(struct ip6gre_net *ign,
286 				       struct ip6_tnl *t)
287 {
288 	if (t->parms.collect_md)
289 		rcu_assign_pointer(ign->collect_md_tun_erspan, NULL);
290 }
291 
292 static inline struct ip6_tnl __rcu **ip6gre_bucket(struct ip6gre_net *ign,
293 		const struct ip6_tnl *t)
294 {
295 	return __ip6gre_bucket(ign, &t->parms);
296 }
297 
298 static void ip6gre_tunnel_link(struct ip6gre_net *ign, struct ip6_tnl *t)
299 {
300 	struct ip6_tnl __rcu **tp = ip6gre_bucket(ign, t);
301 
302 	rcu_assign_pointer(t->next, rtnl_dereference(*tp));
303 	rcu_assign_pointer(*tp, t);
304 }
305 
306 static void ip6gre_tunnel_unlink(struct ip6gre_net *ign, struct ip6_tnl *t)
307 {
308 	struct ip6_tnl __rcu **tp;
309 	struct ip6_tnl *iter;
310 
311 	for (tp = ip6gre_bucket(ign, t);
312 	     (iter = rtnl_dereference(*tp)) != NULL;
313 	     tp = &iter->next) {
314 		if (t == iter) {
315 			rcu_assign_pointer(*tp, t->next);
316 			break;
317 		}
318 	}
319 }
320 
321 static struct ip6_tnl *ip6gre_tunnel_find(struct net *net,
322 					   const struct __ip6_tnl_parm *parms,
323 					   int type)
324 {
325 	const struct in6_addr *remote = &parms->raddr;
326 	const struct in6_addr *local = &parms->laddr;
327 	__be32 key = parms->i_key;
328 	int link = parms->link;
329 	struct ip6_tnl *t;
330 	struct ip6_tnl __rcu **tp;
331 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
332 
333 	for (tp = __ip6gre_bucket(ign, parms);
334 	     (t = rtnl_dereference(*tp)) != NULL;
335 	     tp = &t->next)
336 		if (ipv6_addr_equal(local, &t->parms.laddr) &&
337 		    ipv6_addr_equal(remote, &t->parms.raddr) &&
338 		    key == t->parms.i_key &&
339 		    link == t->parms.link &&
340 		    type == t->dev->type)
341 			break;
342 
343 	return t;
344 }
345 
346 static struct ip6_tnl *ip6gre_tunnel_locate(struct net *net,
347 		const struct __ip6_tnl_parm *parms, int create)
348 {
349 	struct ip6_tnl *t, *nt;
350 	struct net_device *dev;
351 	char name[IFNAMSIZ];
352 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
353 
354 	t = ip6gre_tunnel_find(net, parms, ARPHRD_IP6GRE);
355 	if (t && create)
356 		return NULL;
357 	if (t || !create)
358 		return t;
359 
360 	if (parms->name[0]) {
361 		if (!dev_valid_name(parms->name))
362 			return NULL;
363 		strlcpy(name, parms->name, IFNAMSIZ);
364 	} else {
365 		strcpy(name, "ip6gre%d");
366 	}
367 	dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
368 			   ip6gre_tunnel_setup);
369 	if (!dev)
370 		return NULL;
371 
372 	dev_net_set(dev, net);
373 
374 	nt = netdev_priv(dev);
375 	nt->parms = *parms;
376 	dev->rtnl_link_ops = &ip6gre_link_ops;
377 
378 	nt->dev = dev;
379 	nt->net = dev_net(dev);
380 
381 	if (register_netdevice(dev) < 0)
382 		goto failed_free;
383 
384 	ip6gre_tnl_link_config(nt, 1);
385 
386 	/* Can use a lockless transmit, unless we generate output sequences */
387 	if (!(nt->parms.o_flags & TUNNEL_SEQ))
388 		dev->features |= NETIF_F_LLTX;
389 
390 	dev_hold(dev);
391 	ip6gre_tunnel_link(ign, nt);
392 	return nt;
393 
394 failed_free:
395 	free_netdev(dev);
396 	return NULL;
397 }
398 
399 static void ip6erspan_tunnel_uninit(struct net_device *dev)
400 {
401 	struct ip6_tnl *t = netdev_priv(dev);
402 	struct ip6gre_net *ign = net_generic(t->net, ip6gre_net_id);
403 
404 	ip6erspan_tunnel_unlink_md(ign, t);
405 	ip6gre_tunnel_unlink(ign, t);
406 	dst_cache_reset(&t->dst_cache);
407 	dev_put(dev);
408 }
409 
410 static void ip6gre_tunnel_uninit(struct net_device *dev)
411 {
412 	struct ip6_tnl *t = netdev_priv(dev);
413 	struct ip6gre_net *ign = net_generic(t->net, ip6gre_net_id);
414 
415 	ip6gre_tunnel_unlink_md(ign, t);
416 	ip6gre_tunnel_unlink(ign, t);
417 	if (ign->fb_tunnel_dev == dev)
418 		WRITE_ONCE(ign->fb_tunnel_dev, NULL);
419 	dst_cache_reset(&t->dst_cache);
420 	dev_put(dev);
421 }
422 
423 
424 static int ip6gre_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
425 		       u8 type, u8 code, int offset, __be32 info)
426 {
427 	struct net *net = dev_net(skb->dev);
428 	const struct ipv6hdr *ipv6h;
429 	struct tnl_ptk_info tpi;
430 	struct ip6_tnl *t;
431 
432 	if (gre_parse_header(skb, &tpi, NULL, htons(ETH_P_IPV6),
433 			     offset) < 0)
434 		return -EINVAL;
435 
436 	ipv6h = (const struct ipv6hdr *)skb->data;
437 	t = ip6gre_tunnel_lookup(skb->dev, &ipv6h->daddr, &ipv6h->saddr,
438 				 tpi.key, tpi.proto);
439 	if (!t)
440 		return -ENOENT;
441 
442 	switch (type) {
443 	case ICMPV6_DEST_UNREACH:
444 		net_dbg_ratelimited("%s: Path to destination invalid or inactive!\n",
445 				    t->parms.name);
446 		if (code != ICMPV6_PORT_UNREACH)
447 			break;
448 		return 0;
449 	case ICMPV6_TIME_EXCEED:
450 		if (code == ICMPV6_EXC_HOPLIMIT) {
451 			net_dbg_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
452 					    t->parms.name);
453 			break;
454 		}
455 		return 0;
456 	case ICMPV6_PARAMPROB: {
457 		struct ipv6_tlv_tnl_enc_lim *tel;
458 		__u32 teli;
459 
460 		teli = 0;
461 		if (code == ICMPV6_HDR_FIELD)
462 			teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
463 
464 		if (teli && teli == be32_to_cpu(info) - 2) {
465 			tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
466 			if (tel->encap_limit == 0) {
467 				net_dbg_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
468 						    t->parms.name);
469 			}
470 		} else {
471 			net_dbg_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
472 					    t->parms.name);
473 		}
474 		return 0;
475 	}
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;
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 	ipv6h = ipv6_hdr(skb);
675 
676 	if (offset > 0) {
677 		struct ipv6_tlv_tnl_enc_lim *tel;
678 
679 		tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset];
680 		if (tel->encap_limit == 0) {
681 			icmpv6_send(skb, ICMPV6_PARAMPROB,
682 				    ICMPV6_HDR_FIELD, offset + 2);
683 			return -1;
684 		}
685 		*encap_limit = tel->encap_limit - 1;
686 	} else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) {
687 		*encap_limit = t->parms.encap_limit;
688 	}
689 
690 	memcpy(fl6, &t->fl.u.ip6, sizeof(*fl6));
691 
692 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
693 		*dsfield = ipv6_get_dsfield(ipv6h);
694 	else
695 		*dsfield = ip6_tclass(t->parms.flowinfo);
696 
697 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
698 		fl6->flowlabel |= ip6_flowlabel(ipv6h);
699 
700 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
701 		fl6->flowi6_mark = skb->mark;
702 	else
703 		fl6->flowi6_mark = t->parms.fwmark;
704 
705 	fl6->flowi6_uid = sock_net_uid(dev_net(dev), NULL);
706 
707 	return 0;
708 }
709 
710 static struct ip_tunnel_info *skb_tunnel_info_txcheck(struct sk_buff *skb)
711 {
712 	struct ip_tunnel_info *tun_info;
713 
714 	tun_info = skb_tunnel_info(skb);
715 	if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX)))
716 		return ERR_PTR(-EINVAL);
717 
718 	return tun_info;
719 }
720 
721 static netdev_tx_t __gre6_xmit(struct sk_buff *skb,
722 			       struct net_device *dev, __u8 dsfield,
723 			       struct flowi6 *fl6, int encap_limit,
724 			       __u32 *pmtu, __be16 proto)
725 {
726 	struct ip6_tnl *tunnel = netdev_priv(dev);
727 	__be16 protocol;
728 
729 	if (dev->type == ARPHRD_ETHER)
730 		IPCB(skb)->flags = 0;
731 
732 	if (dev->header_ops && dev->type == ARPHRD_IP6GRE)
733 		fl6->daddr = ((struct ipv6hdr *)skb->data)->daddr;
734 	else
735 		fl6->daddr = tunnel->parms.raddr;
736 
737 	if (skb_cow_head(skb, dev->needed_headroom ?: tunnel->hlen))
738 		return -ENOMEM;
739 
740 	/* Push GRE header. */
741 	protocol = (dev->type == ARPHRD_ETHER) ? htons(ETH_P_TEB) : proto;
742 
743 	if (tunnel->parms.collect_md) {
744 		struct ip_tunnel_info *tun_info;
745 		const struct ip_tunnel_key *key;
746 		__be16 flags;
747 
748 		tun_info = skb_tunnel_info_txcheck(skb);
749 		if (IS_ERR(tun_info) ||
750 		    unlikely(ip_tunnel_info_af(tun_info) != AF_INET6))
751 			return -EINVAL;
752 
753 		key = &tun_info->key;
754 		memset(fl6, 0, sizeof(*fl6));
755 		fl6->flowi6_proto = IPPROTO_GRE;
756 		fl6->daddr = key->u.ipv6.dst;
757 		fl6->flowlabel = key->label;
758 		fl6->flowi6_uid = sock_net_uid(dev_net(dev), NULL);
759 
760 		dsfield = key->tos;
761 		flags = key->tun_flags &
762 			(TUNNEL_CSUM | TUNNEL_KEY | TUNNEL_SEQ);
763 		tunnel->tun_hlen = gre_calc_hlen(flags);
764 
765 		gre_build_header(skb, tunnel->tun_hlen,
766 				 flags, protocol,
767 				 tunnel_id_to_key32(tun_info->key.tun_id),
768 				 (flags & TUNNEL_SEQ) ? htonl(tunnel->o_seqno++)
769 						      : 0);
770 
771 	} else {
772 		if (tunnel->parms.o_flags & TUNNEL_SEQ)
773 			tunnel->o_seqno++;
774 
775 		gre_build_header(skb, tunnel->tun_hlen, tunnel->parms.o_flags,
776 				 protocol, tunnel->parms.o_key,
777 				 htonl(tunnel->o_seqno));
778 	}
779 
780 	return ip6_tnl_xmit(skb, dev, dsfield, fl6, encap_limit, pmtu,
781 			    NEXTHDR_GRE);
782 }
783 
784 static inline int ip6gre_xmit_ipv4(struct sk_buff *skb, struct net_device *dev)
785 {
786 	struct ip6_tnl *t = netdev_priv(dev);
787 	int encap_limit = -1;
788 	struct flowi6 fl6;
789 	__u8 dsfield = 0;
790 	__u32 mtu;
791 	int err;
792 
793 	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
794 
795 	if (!t->parms.collect_md)
796 		prepare_ip6gre_xmit_ipv4(skb, dev, &fl6,
797 					 &dsfield, &encap_limit);
798 
799 	err = gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM));
800 	if (err)
801 		return -1;
802 
803 	err = __gre6_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
804 			  skb->protocol);
805 	if (err != 0) {
806 		/* XXX: send ICMP error even if DF is not set. */
807 		if (err == -EMSGSIZE)
808 			icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
809 				  htonl(mtu));
810 		return -1;
811 	}
812 
813 	return 0;
814 }
815 
816 static inline int ip6gre_xmit_ipv6(struct sk_buff *skb, struct net_device *dev)
817 {
818 	struct ip6_tnl *t = netdev_priv(dev);
819 	struct ipv6hdr *ipv6h = ipv6_hdr(skb);
820 	int encap_limit = -1;
821 	struct flowi6 fl6;
822 	__u8 dsfield = 0;
823 	__u32 mtu;
824 	int err;
825 
826 	if (ipv6_addr_equal(&t->parms.raddr, &ipv6h->saddr))
827 		return -1;
828 
829 	if (!t->parms.collect_md &&
830 	    prepare_ip6gre_xmit_ipv6(skb, dev, &fl6, &dsfield, &encap_limit))
831 		return -1;
832 
833 	if (gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM)))
834 		return -1;
835 
836 	err = __gre6_xmit(skb, dev, dsfield, &fl6, encap_limit,
837 			  &mtu, skb->protocol);
838 	if (err != 0) {
839 		if (err == -EMSGSIZE)
840 			icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
841 		return -1;
842 	}
843 
844 	return 0;
845 }
846 
847 /**
848  * ip6gre_tnl_addr_conflict - compare packet addresses to tunnel's own
849  *   @t: the outgoing tunnel device
850  *   @hdr: IPv6 header from the incoming packet
851  *
852  * Description:
853  *   Avoid trivial tunneling loop by checking that tunnel exit-point
854  *   doesn't match source of incoming packet.
855  *
856  * Return:
857  *   1 if conflict,
858  *   0 else
859  **/
860 
861 static inline bool ip6gre_tnl_addr_conflict(const struct ip6_tnl *t,
862 	const struct ipv6hdr *hdr)
863 {
864 	return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
865 }
866 
867 static int ip6gre_xmit_other(struct sk_buff *skb, struct net_device *dev)
868 {
869 	struct ip6_tnl *t = netdev_priv(dev);
870 	int encap_limit = -1;
871 	struct flowi6 fl6;
872 	__u32 mtu;
873 	int err;
874 
875 	if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
876 		encap_limit = t->parms.encap_limit;
877 
878 	if (!t->parms.collect_md)
879 		memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
880 
881 	err = gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM));
882 	if (err)
883 		return err;
884 
885 	err = __gre6_xmit(skb, dev, 0, &fl6, encap_limit, &mtu, skb->protocol);
886 
887 	return err;
888 }
889 
890 static netdev_tx_t ip6gre_tunnel_xmit(struct sk_buff *skb,
891 	struct net_device *dev)
892 {
893 	struct ip6_tnl *t = netdev_priv(dev);
894 	struct net_device_stats *stats = &t->dev->stats;
895 	int ret;
896 
897 	if (!pskb_inet_may_pull(skb))
898 		goto tx_err;
899 
900 	if (!ip6_tnl_xmit_ctl(t, &t->parms.laddr, &t->parms.raddr))
901 		goto tx_err;
902 
903 	switch (skb->protocol) {
904 	case htons(ETH_P_IP):
905 		ret = ip6gre_xmit_ipv4(skb, dev);
906 		break;
907 	case htons(ETH_P_IPV6):
908 		ret = ip6gre_xmit_ipv6(skb, dev);
909 		break;
910 	default:
911 		ret = ip6gre_xmit_other(skb, dev);
912 		break;
913 	}
914 
915 	if (ret < 0)
916 		goto tx_err;
917 
918 	return NETDEV_TX_OK;
919 
920 tx_err:
921 	if (!t->parms.collect_md || !IS_ERR(skb_tunnel_info_txcheck(skb)))
922 		stats->tx_errors++;
923 	stats->tx_dropped++;
924 	kfree_skb(skb);
925 	return NETDEV_TX_OK;
926 }
927 
928 static netdev_tx_t ip6erspan_tunnel_xmit(struct sk_buff *skb,
929 					 struct net_device *dev)
930 {
931 	struct ip_tunnel_info *tun_info = NULL;
932 	struct ip6_tnl *t = netdev_priv(dev);
933 	struct dst_entry *dst = skb_dst(skb);
934 	struct net_device_stats *stats;
935 	bool truncate = false;
936 	int encap_limit = -1;
937 	__u8 dsfield = false;
938 	struct flowi6 fl6;
939 	int err = -EINVAL;
940 	__be16 proto;
941 	__u32 mtu;
942 	int nhoff;
943 	int thoff;
944 
945 	if (!pskb_inet_may_pull(skb))
946 		goto tx_err;
947 
948 	if (!ip6_tnl_xmit_ctl(t, &t->parms.laddr, &t->parms.raddr))
949 		goto tx_err;
950 
951 	if (gre_handle_offloads(skb, false))
952 		goto tx_err;
953 
954 	if (skb->len > dev->mtu + dev->hard_header_len) {
955 		pskb_trim(skb, dev->mtu + dev->hard_header_len);
956 		truncate = true;
957 	}
958 
959 	nhoff = skb_network_header(skb) - skb_mac_header(skb);
960 	if (skb->protocol == htons(ETH_P_IP) &&
961 	    (ntohs(ip_hdr(skb)->tot_len) > skb->len - nhoff))
962 		truncate = true;
963 
964 	thoff = skb_transport_header(skb) - skb_mac_header(skb);
965 	if (skb->protocol == htons(ETH_P_IPV6) &&
966 	    (ntohs(ipv6_hdr(skb)->payload_len) > skb->len - thoff))
967 		truncate = true;
968 
969 	if (skb_cow_head(skb, dev->needed_headroom ?: t->hlen))
970 		goto tx_err;
971 
972 	t->parms.o_flags &= ~TUNNEL_KEY;
973 	IPCB(skb)->flags = 0;
974 
975 	/* For collect_md mode, derive fl6 from the tunnel key,
976 	 * for native mode, call prepare_ip6gre_xmit_{ipv4,ipv6}.
977 	 */
978 	if (t->parms.collect_md) {
979 		const struct ip_tunnel_key *key;
980 		struct erspan_metadata *md;
981 		__be32 tun_id;
982 
983 		tun_info = skb_tunnel_info_txcheck(skb);
984 		if (IS_ERR(tun_info) ||
985 		    unlikely(ip_tunnel_info_af(tun_info) != AF_INET6))
986 			goto tx_err;
987 
988 		key = &tun_info->key;
989 		memset(&fl6, 0, sizeof(fl6));
990 		fl6.flowi6_proto = IPPROTO_GRE;
991 		fl6.daddr = key->u.ipv6.dst;
992 		fl6.flowlabel = key->label;
993 		fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
994 
995 		dsfield = key->tos;
996 		if (!(tun_info->key.tun_flags & TUNNEL_ERSPAN_OPT))
997 			goto tx_err;
998 		if (tun_info->options_len < sizeof(*md))
999 			goto tx_err;
1000 		md = ip_tunnel_info_opts(tun_info);
1001 
1002 		tun_id = tunnel_id_to_key32(key->tun_id);
1003 		if (md->version == 1) {
1004 			erspan_build_header(skb,
1005 					    ntohl(tun_id),
1006 					    ntohl(md->u.index), truncate,
1007 					    false);
1008 		} else if (md->version == 2) {
1009 			erspan_build_header_v2(skb,
1010 					       ntohl(tun_id),
1011 					       md->u.md2.dir,
1012 					       get_hwid(&md->u.md2),
1013 					       truncate, false);
1014 		} else {
1015 			goto tx_err;
1016 		}
1017 	} else {
1018 		switch (skb->protocol) {
1019 		case htons(ETH_P_IP):
1020 			memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1021 			prepare_ip6gre_xmit_ipv4(skb, dev, &fl6,
1022 						 &dsfield, &encap_limit);
1023 			break;
1024 		case htons(ETH_P_IPV6):
1025 			if (ipv6_addr_equal(&t->parms.raddr, &ipv6_hdr(skb)->saddr))
1026 				goto tx_err;
1027 			if (prepare_ip6gre_xmit_ipv6(skb, dev, &fl6,
1028 						     &dsfield, &encap_limit))
1029 				goto tx_err;
1030 			break;
1031 		default:
1032 			memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
1033 			break;
1034 		}
1035 
1036 		if (t->parms.erspan_ver == 1)
1037 			erspan_build_header(skb, ntohl(t->parms.o_key),
1038 					    t->parms.index,
1039 					    truncate, false);
1040 		else if (t->parms.erspan_ver == 2)
1041 			erspan_build_header_v2(skb, ntohl(t->parms.o_key),
1042 					       t->parms.dir,
1043 					       t->parms.hwid,
1044 					       truncate, false);
1045 		else
1046 			goto tx_err;
1047 
1048 		fl6.daddr = t->parms.raddr;
1049 	}
1050 
1051 	/* Push GRE header. */
1052 	proto = (t->parms.erspan_ver == 1) ? htons(ETH_P_ERSPAN)
1053 					   : htons(ETH_P_ERSPAN2);
1054 	gre_build_header(skb, 8, TUNNEL_SEQ, proto, 0, htonl(t->o_seqno++));
1055 
1056 	/* TooBig packet may have updated dst->dev's mtu */
1057 	if (!t->parms.collect_md && dst && dst_mtu(dst) > dst->dev->mtu)
1058 		dst->ops->update_pmtu(dst, NULL, skb, dst->dev->mtu, false);
1059 
1060 	err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
1061 			   NEXTHDR_GRE);
1062 	if (err != 0) {
1063 		/* XXX: send ICMP error even if DF is not set. */
1064 		if (err == -EMSGSIZE) {
1065 			if (skb->protocol == htons(ETH_P_IP))
1066 				icmp_send(skb, ICMP_DEST_UNREACH,
1067 					  ICMP_FRAG_NEEDED, htonl(mtu));
1068 			else
1069 				icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
1070 		}
1071 
1072 		goto tx_err;
1073 	}
1074 	return NETDEV_TX_OK;
1075 
1076 tx_err:
1077 	stats = &t->dev->stats;
1078 	if (!IS_ERR(tun_info))
1079 		stats->tx_errors++;
1080 	stats->tx_dropped++;
1081 	kfree_skb(skb);
1082 	return NETDEV_TX_OK;
1083 }
1084 
1085 static void ip6gre_tnl_link_config_common(struct ip6_tnl *t)
1086 {
1087 	struct net_device *dev = t->dev;
1088 	struct __ip6_tnl_parm *p = &t->parms;
1089 	struct flowi6 *fl6 = &t->fl.u.ip6;
1090 
1091 	if (dev->type != ARPHRD_ETHER) {
1092 		memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
1093 		memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
1094 	}
1095 
1096 	/* Set up flowi template */
1097 	fl6->saddr = p->laddr;
1098 	fl6->daddr = p->raddr;
1099 	fl6->flowi6_oif = p->link;
1100 	fl6->flowlabel = 0;
1101 	fl6->flowi6_proto = IPPROTO_GRE;
1102 
1103 	if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
1104 		fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
1105 	if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
1106 		fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
1107 
1108 	p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
1109 	p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
1110 
1111 	if (p->flags&IP6_TNL_F_CAP_XMIT &&
1112 			p->flags&IP6_TNL_F_CAP_RCV && dev->type != ARPHRD_ETHER)
1113 		dev->flags |= IFF_POINTOPOINT;
1114 	else
1115 		dev->flags &= ~IFF_POINTOPOINT;
1116 }
1117 
1118 static void ip6gre_tnl_link_config_route(struct ip6_tnl *t, int set_mtu,
1119 					 int t_hlen)
1120 {
1121 	const struct __ip6_tnl_parm *p = &t->parms;
1122 	struct net_device *dev = t->dev;
1123 
1124 	if (p->flags & IP6_TNL_F_CAP_XMIT) {
1125 		int strict = (ipv6_addr_type(&p->raddr) &
1126 			      (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
1127 
1128 		struct rt6_info *rt = rt6_lookup(t->net,
1129 						 &p->raddr, &p->laddr,
1130 						 p->link, NULL, strict);
1131 
1132 		if (!rt)
1133 			return;
1134 
1135 		if (rt->dst.dev) {
1136 			unsigned short dst_len = rt->dst.dev->hard_header_len +
1137 						 t_hlen;
1138 
1139 			if (t->dev->header_ops)
1140 				dev->hard_header_len = dst_len;
1141 			else
1142 				dev->needed_headroom = dst_len;
1143 
1144 			if (set_mtu) {
1145 				dev->mtu = rt->dst.dev->mtu - t_hlen;
1146 				if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1147 					dev->mtu -= 8;
1148 				if (dev->type == ARPHRD_ETHER)
1149 					dev->mtu -= ETH_HLEN;
1150 
1151 				if (dev->mtu < IPV6_MIN_MTU)
1152 					dev->mtu = IPV6_MIN_MTU;
1153 			}
1154 		}
1155 		ip6_rt_put(rt);
1156 	}
1157 }
1158 
1159 static int ip6gre_calc_hlen(struct ip6_tnl *tunnel)
1160 {
1161 	int t_hlen;
1162 
1163 	tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags);
1164 	tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen;
1165 
1166 	t_hlen = tunnel->hlen + sizeof(struct ipv6hdr);
1167 
1168 	if (tunnel->dev->header_ops)
1169 		tunnel->dev->hard_header_len = LL_MAX_HEADER + t_hlen;
1170 	else
1171 		tunnel->dev->needed_headroom = LL_MAX_HEADER + t_hlen;
1172 
1173 	return t_hlen;
1174 }
1175 
1176 static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu)
1177 {
1178 	ip6gre_tnl_link_config_common(t);
1179 	ip6gre_tnl_link_config_route(t, set_mtu, ip6gre_calc_hlen(t));
1180 }
1181 
1182 static void ip6gre_tnl_copy_tnl_parm(struct ip6_tnl *t,
1183 				     const struct __ip6_tnl_parm *p)
1184 {
1185 	t->parms.laddr = p->laddr;
1186 	t->parms.raddr = p->raddr;
1187 	t->parms.flags = p->flags;
1188 	t->parms.hop_limit = p->hop_limit;
1189 	t->parms.encap_limit = p->encap_limit;
1190 	t->parms.flowinfo = p->flowinfo;
1191 	t->parms.link = p->link;
1192 	t->parms.proto = p->proto;
1193 	t->parms.i_key = p->i_key;
1194 	t->parms.o_key = p->o_key;
1195 	t->parms.i_flags = p->i_flags;
1196 	t->parms.o_flags = p->o_flags;
1197 	t->parms.fwmark = p->fwmark;
1198 	t->parms.erspan_ver = p->erspan_ver;
1199 	t->parms.index = p->index;
1200 	t->parms.dir = p->dir;
1201 	t->parms.hwid = p->hwid;
1202 	dst_cache_reset(&t->dst_cache);
1203 }
1204 
1205 static int ip6gre_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p,
1206 			     int set_mtu)
1207 {
1208 	ip6gre_tnl_copy_tnl_parm(t, p);
1209 	ip6gre_tnl_link_config(t, set_mtu);
1210 	return 0;
1211 }
1212 
1213 static void ip6gre_tnl_parm_from_user(struct __ip6_tnl_parm *p,
1214 	const struct ip6_tnl_parm2 *u)
1215 {
1216 	p->laddr = u->laddr;
1217 	p->raddr = u->raddr;
1218 	p->flags = u->flags;
1219 	p->hop_limit = u->hop_limit;
1220 	p->encap_limit = u->encap_limit;
1221 	p->flowinfo = u->flowinfo;
1222 	p->link = u->link;
1223 	p->i_key = u->i_key;
1224 	p->o_key = u->o_key;
1225 	p->i_flags = gre_flags_to_tnl_flags(u->i_flags);
1226 	p->o_flags = gre_flags_to_tnl_flags(u->o_flags);
1227 	memcpy(p->name, u->name, sizeof(u->name));
1228 }
1229 
1230 static void ip6gre_tnl_parm_to_user(struct ip6_tnl_parm2 *u,
1231 	const struct __ip6_tnl_parm *p)
1232 {
1233 	u->proto = IPPROTO_GRE;
1234 	u->laddr = p->laddr;
1235 	u->raddr = p->raddr;
1236 	u->flags = p->flags;
1237 	u->hop_limit = p->hop_limit;
1238 	u->encap_limit = p->encap_limit;
1239 	u->flowinfo = p->flowinfo;
1240 	u->link = p->link;
1241 	u->i_key = p->i_key;
1242 	u->o_key = p->o_key;
1243 	u->i_flags = gre_tnl_flags_to_gre_flags(p->i_flags);
1244 	u->o_flags = gre_tnl_flags_to_gre_flags(p->o_flags);
1245 	memcpy(u->name, p->name, sizeof(u->name));
1246 }
1247 
1248 static int ip6gre_tunnel_ioctl(struct net_device *dev,
1249 	struct ifreq *ifr, int cmd)
1250 {
1251 	int err = 0;
1252 	struct ip6_tnl_parm2 p;
1253 	struct __ip6_tnl_parm p1;
1254 	struct ip6_tnl *t = netdev_priv(dev);
1255 	struct net *net = t->net;
1256 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1257 
1258 	memset(&p1, 0, sizeof(p1));
1259 
1260 	switch (cmd) {
1261 	case SIOCGETTUNNEL:
1262 		if (dev == ign->fb_tunnel_dev) {
1263 			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1264 				err = -EFAULT;
1265 				break;
1266 			}
1267 			ip6gre_tnl_parm_from_user(&p1, &p);
1268 			t = ip6gre_tunnel_locate(net, &p1, 0);
1269 			if (!t)
1270 				t = netdev_priv(dev);
1271 		}
1272 		memset(&p, 0, sizeof(p));
1273 		ip6gre_tnl_parm_to_user(&p, &t->parms);
1274 		if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1275 			err = -EFAULT;
1276 		break;
1277 
1278 	case SIOCADDTUNNEL:
1279 	case SIOCCHGTUNNEL:
1280 		err = -EPERM;
1281 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1282 			goto done;
1283 
1284 		err = -EFAULT;
1285 		if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1286 			goto done;
1287 
1288 		err = -EINVAL;
1289 		if ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING))
1290 			goto done;
1291 
1292 		if (!(p.i_flags&GRE_KEY))
1293 			p.i_key = 0;
1294 		if (!(p.o_flags&GRE_KEY))
1295 			p.o_key = 0;
1296 
1297 		ip6gre_tnl_parm_from_user(&p1, &p);
1298 		t = ip6gre_tunnel_locate(net, &p1, cmd == SIOCADDTUNNEL);
1299 
1300 		if (dev != ign->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
1301 			if (t) {
1302 				if (t->dev != dev) {
1303 					err = -EEXIST;
1304 					break;
1305 				}
1306 			} else {
1307 				t = netdev_priv(dev);
1308 
1309 				ip6gre_tunnel_unlink(ign, t);
1310 				synchronize_net();
1311 				ip6gre_tnl_change(t, &p1, 1);
1312 				ip6gre_tunnel_link(ign, t);
1313 				netdev_state_change(dev);
1314 			}
1315 		}
1316 
1317 		if (t) {
1318 			err = 0;
1319 
1320 			memset(&p, 0, sizeof(p));
1321 			ip6gre_tnl_parm_to_user(&p, &t->parms);
1322 			if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1323 				err = -EFAULT;
1324 		} else
1325 			err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1326 		break;
1327 
1328 	case SIOCDELTUNNEL:
1329 		err = -EPERM;
1330 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1331 			goto done;
1332 
1333 		if (dev == ign->fb_tunnel_dev) {
1334 			err = -EFAULT;
1335 			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1336 				goto done;
1337 			err = -ENOENT;
1338 			ip6gre_tnl_parm_from_user(&p1, &p);
1339 			t = ip6gre_tunnel_locate(net, &p1, 0);
1340 			if (!t)
1341 				goto done;
1342 			err = -EPERM;
1343 			if (t == netdev_priv(ign->fb_tunnel_dev))
1344 				goto done;
1345 			dev = t->dev;
1346 		}
1347 		unregister_netdevice(dev);
1348 		err = 0;
1349 		break;
1350 
1351 	default:
1352 		err = -EINVAL;
1353 	}
1354 
1355 done:
1356 	return err;
1357 }
1358 
1359 static int ip6gre_header(struct sk_buff *skb, struct net_device *dev,
1360 			 unsigned short type, const void *daddr,
1361 			 const void *saddr, unsigned int len)
1362 {
1363 	struct ip6_tnl *t = netdev_priv(dev);
1364 	struct ipv6hdr *ipv6h;
1365 	__be16 *p;
1366 
1367 	ipv6h = skb_push(skb, t->hlen + sizeof(*ipv6h));
1368 	ip6_flow_hdr(ipv6h, 0, ip6_make_flowlabel(dev_net(dev), skb,
1369 						  t->fl.u.ip6.flowlabel,
1370 						  true, &t->fl.u.ip6));
1371 	ipv6h->hop_limit = t->parms.hop_limit;
1372 	ipv6h->nexthdr = NEXTHDR_GRE;
1373 	ipv6h->saddr = t->parms.laddr;
1374 	ipv6h->daddr = t->parms.raddr;
1375 
1376 	p = (__be16 *)(ipv6h + 1);
1377 	p[0] = t->parms.o_flags;
1378 	p[1] = htons(type);
1379 
1380 	/*
1381 	 *	Set the source hardware address.
1382 	 */
1383 
1384 	if (saddr)
1385 		memcpy(&ipv6h->saddr, saddr, sizeof(struct in6_addr));
1386 	if (daddr)
1387 		memcpy(&ipv6h->daddr, daddr, sizeof(struct in6_addr));
1388 	if (!ipv6_addr_any(&ipv6h->daddr))
1389 		return t->hlen;
1390 
1391 	return -t->hlen;
1392 }
1393 
1394 static const struct header_ops ip6gre_header_ops = {
1395 	.create	= ip6gre_header,
1396 };
1397 
1398 static const struct net_device_ops ip6gre_netdev_ops = {
1399 	.ndo_init		= ip6gre_tunnel_init,
1400 	.ndo_uninit		= ip6gre_tunnel_uninit,
1401 	.ndo_start_xmit		= ip6gre_tunnel_xmit,
1402 	.ndo_do_ioctl		= ip6gre_tunnel_ioctl,
1403 	.ndo_change_mtu		= ip6_tnl_change_mtu,
1404 	.ndo_get_stats64	= dev_get_tstats64,
1405 	.ndo_get_iflink		= ip6_tnl_get_iflink,
1406 };
1407 
1408 static void ip6gre_dev_free(struct net_device *dev)
1409 {
1410 	struct ip6_tnl *t = netdev_priv(dev);
1411 
1412 	gro_cells_destroy(&t->gro_cells);
1413 	dst_cache_destroy(&t->dst_cache);
1414 	free_percpu(dev->tstats);
1415 }
1416 
1417 static void ip6gre_tunnel_setup(struct net_device *dev)
1418 {
1419 	dev->netdev_ops = &ip6gre_netdev_ops;
1420 	dev->needs_free_netdev = true;
1421 	dev->priv_destructor = ip6gre_dev_free;
1422 
1423 	dev->type = ARPHRD_IP6GRE;
1424 
1425 	dev->flags |= IFF_NOARP;
1426 	dev->addr_len = sizeof(struct in6_addr);
1427 	netif_keep_dst(dev);
1428 	/* This perm addr will be used as interface identifier by IPv6 */
1429 	dev->addr_assign_type = NET_ADDR_RANDOM;
1430 	eth_random_addr(dev->perm_addr);
1431 }
1432 
1433 #define GRE6_FEATURES (NETIF_F_SG |		\
1434 		       NETIF_F_FRAGLIST |	\
1435 		       NETIF_F_HIGHDMA |	\
1436 		       NETIF_F_HW_CSUM)
1437 
1438 static void ip6gre_tnl_init_features(struct net_device *dev)
1439 {
1440 	struct ip6_tnl *nt = netdev_priv(dev);
1441 
1442 	dev->features		|= GRE6_FEATURES;
1443 	dev->hw_features	|= GRE6_FEATURES;
1444 
1445 	if (!(nt->parms.o_flags & TUNNEL_SEQ)) {
1446 		/* TCP offload with GRE SEQ is not supported, nor
1447 		 * can we support 2 levels of outer headers requiring
1448 		 * an update.
1449 		 */
1450 		if (!(nt->parms.o_flags & TUNNEL_CSUM) ||
1451 		    nt->encap.type == TUNNEL_ENCAP_NONE) {
1452 			dev->features    |= NETIF_F_GSO_SOFTWARE;
1453 			dev->hw_features |= NETIF_F_GSO_SOFTWARE;
1454 		}
1455 
1456 		/* Can use a lockless transmit, unless we generate
1457 		 * output sequences
1458 		 */
1459 		dev->features |= NETIF_F_LLTX;
1460 	}
1461 }
1462 
1463 static int ip6gre_tunnel_init_common(struct net_device *dev)
1464 {
1465 	struct ip6_tnl *tunnel;
1466 	int ret;
1467 	int t_hlen;
1468 
1469 	tunnel = netdev_priv(dev);
1470 
1471 	tunnel->dev = dev;
1472 	tunnel->net = dev_net(dev);
1473 	strcpy(tunnel->parms.name, dev->name);
1474 
1475 	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1476 	if (!dev->tstats)
1477 		return -ENOMEM;
1478 
1479 	ret = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL);
1480 	if (ret)
1481 		goto cleanup_alloc_pcpu_stats;
1482 
1483 	ret = gro_cells_init(&tunnel->gro_cells, dev);
1484 	if (ret)
1485 		goto cleanup_dst_cache_init;
1486 
1487 	t_hlen = ip6gre_calc_hlen(tunnel);
1488 	dev->mtu = ETH_DATA_LEN - t_hlen;
1489 	if (dev->type == ARPHRD_ETHER)
1490 		dev->mtu -= ETH_HLEN;
1491 	if (!(tunnel->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1492 		dev->mtu -= 8;
1493 
1494 	if (tunnel->parms.collect_md) {
1495 		netif_keep_dst(dev);
1496 	}
1497 	ip6gre_tnl_init_features(dev);
1498 
1499 	return 0;
1500 
1501 cleanup_dst_cache_init:
1502 	dst_cache_destroy(&tunnel->dst_cache);
1503 cleanup_alloc_pcpu_stats:
1504 	free_percpu(dev->tstats);
1505 	dev->tstats = NULL;
1506 	return ret;
1507 }
1508 
1509 static int ip6gre_tunnel_init(struct net_device *dev)
1510 {
1511 	struct ip6_tnl *tunnel;
1512 	int ret;
1513 
1514 	ret = ip6gre_tunnel_init_common(dev);
1515 	if (ret)
1516 		return ret;
1517 
1518 	tunnel = netdev_priv(dev);
1519 
1520 	if (tunnel->parms.collect_md)
1521 		return 0;
1522 
1523 	memcpy(dev->dev_addr, &tunnel->parms.laddr, sizeof(struct in6_addr));
1524 	memcpy(dev->broadcast, &tunnel->parms.raddr, sizeof(struct in6_addr));
1525 
1526 	if (ipv6_addr_any(&tunnel->parms.raddr))
1527 		dev->header_ops = &ip6gre_header_ops;
1528 
1529 	return 0;
1530 }
1531 
1532 static void ip6gre_fb_tunnel_init(struct net_device *dev)
1533 {
1534 	struct ip6_tnl *tunnel = netdev_priv(dev);
1535 
1536 	tunnel->dev = dev;
1537 	tunnel->net = dev_net(dev);
1538 	strcpy(tunnel->parms.name, dev->name);
1539 
1540 	tunnel->hlen		= sizeof(struct ipv6hdr) + 4;
1541 
1542 	dev_hold(dev);
1543 }
1544 
1545 static struct inet6_protocol ip6gre_protocol __read_mostly = {
1546 	.handler     = gre_rcv,
1547 	.err_handler = ip6gre_err,
1548 	.flags       = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1549 };
1550 
1551 static void ip6gre_destroy_tunnels(struct net *net, struct list_head *head)
1552 {
1553 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1554 	struct net_device *dev, *aux;
1555 	int prio;
1556 
1557 	for_each_netdev_safe(net, dev, aux)
1558 		if (dev->rtnl_link_ops == &ip6gre_link_ops ||
1559 		    dev->rtnl_link_ops == &ip6gre_tap_ops ||
1560 		    dev->rtnl_link_ops == &ip6erspan_tap_ops)
1561 			unregister_netdevice_queue(dev, head);
1562 
1563 	for (prio = 0; prio < 4; prio++) {
1564 		int h;
1565 		for (h = 0; h < IP6_GRE_HASH_SIZE; h++) {
1566 			struct ip6_tnl *t;
1567 
1568 			t = rtnl_dereference(ign->tunnels[prio][h]);
1569 
1570 			while (t) {
1571 				/* If dev is in the same netns, it has already
1572 				 * been added to the list by the previous loop.
1573 				 */
1574 				if (!net_eq(dev_net(t->dev), net))
1575 					unregister_netdevice_queue(t->dev,
1576 								   head);
1577 				t = rtnl_dereference(t->next);
1578 			}
1579 		}
1580 	}
1581 }
1582 
1583 static int __net_init ip6gre_init_net(struct net *net)
1584 {
1585 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1586 	struct net_device *ndev;
1587 	int err;
1588 
1589 	if (!net_has_fallback_tunnels(net))
1590 		return 0;
1591 	ndev = alloc_netdev(sizeof(struct ip6_tnl), "ip6gre0",
1592 			    NET_NAME_UNKNOWN, ip6gre_tunnel_setup);
1593 	if (!ndev) {
1594 		err = -ENOMEM;
1595 		goto err_alloc_dev;
1596 	}
1597 	ign->fb_tunnel_dev = ndev;
1598 	dev_net_set(ign->fb_tunnel_dev, net);
1599 	/* FB netdevice is special: we have one, and only one per netns.
1600 	 * Allowing to move it to another netns is clearly unsafe.
1601 	 */
1602 	ign->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
1603 
1604 
1605 	ip6gre_fb_tunnel_init(ign->fb_tunnel_dev);
1606 	ign->fb_tunnel_dev->rtnl_link_ops = &ip6gre_link_ops;
1607 
1608 	err = register_netdev(ign->fb_tunnel_dev);
1609 	if (err)
1610 		goto err_reg_dev;
1611 
1612 	rcu_assign_pointer(ign->tunnels_wc[0],
1613 			   netdev_priv(ign->fb_tunnel_dev));
1614 	return 0;
1615 
1616 err_reg_dev:
1617 	free_netdev(ndev);
1618 err_alloc_dev:
1619 	return err;
1620 }
1621 
1622 static void __net_exit ip6gre_exit_batch_net(struct list_head *net_list)
1623 {
1624 	struct net *net;
1625 	LIST_HEAD(list);
1626 
1627 	rtnl_lock();
1628 	list_for_each_entry(net, net_list, exit_list)
1629 		ip6gre_destroy_tunnels(net, &list);
1630 	unregister_netdevice_many(&list);
1631 	rtnl_unlock();
1632 }
1633 
1634 static struct pernet_operations ip6gre_net_ops = {
1635 	.init = ip6gre_init_net,
1636 	.exit_batch = ip6gre_exit_batch_net,
1637 	.id   = &ip6gre_net_id,
1638 	.size = sizeof(struct ip6gre_net),
1639 };
1640 
1641 static int ip6gre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[],
1642 				  struct netlink_ext_ack *extack)
1643 {
1644 	__be16 flags;
1645 
1646 	if (!data)
1647 		return 0;
1648 
1649 	flags = 0;
1650 	if (data[IFLA_GRE_IFLAGS])
1651 		flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1652 	if (data[IFLA_GRE_OFLAGS])
1653 		flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1654 	if (flags & (GRE_VERSION|GRE_ROUTING))
1655 		return -EINVAL;
1656 
1657 	return 0;
1658 }
1659 
1660 static int ip6gre_tap_validate(struct nlattr *tb[], struct nlattr *data[],
1661 			       struct netlink_ext_ack *extack)
1662 {
1663 	struct in6_addr daddr;
1664 
1665 	if (tb[IFLA_ADDRESS]) {
1666 		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1667 			return -EINVAL;
1668 		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1669 			return -EADDRNOTAVAIL;
1670 	}
1671 
1672 	if (!data)
1673 		goto out;
1674 
1675 	if (data[IFLA_GRE_REMOTE]) {
1676 		daddr = nla_get_in6_addr(data[IFLA_GRE_REMOTE]);
1677 		if (ipv6_addr_any(&daddr))
1678 			return -EINVAL;
1679 	}
1680 
1681 out:
1682 	return ip6gre_tunnel_validate(tb, data, extack);
1683 }
1684 
1685 static int ip6erspan_tap_validate(struct nlattr *tb[], struct nlattr *data[],
1686 				  struct netlink_ext_ack *extack)
1687 {
1688 	__be16 flags = 0;
1689 	int ret, ver = 0;
1690 
1691 	if (!data)
1692 		return 0;
1693 
1694 	ret = ip6gre_tap_validate(tb, data, extack);
1695 	if (ret)
1696 		return ret;
1697 
1698 	/* ERSPAN should only have GRE sequence and key flag */
1699 	if (data[IFLA_GRE_OFLAGS])
1700 		flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1701 	if (data[IFLA_GRE_IFLAGS])
1702 		flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1703 	if (!data[IFLA_GRE_COLLECT_METADATA] &&
1704 	    flags != (GRE_SEQ | GRE_KEY))
1705 		return -EINVAL;
1706 
1707 	/* ERSPAN Session ID only has 10-bit. Since we reuse
1708 	 * 32-bit key field as ID, check it's range.
1709 	 */
1710 	if (data[IFLA_GRE_IKEY] &&
1711 	    (ntohl(nla_get_be32(data[IFLA_GRE_IKEY])) & ~ID_MASK))
1712 		return -EINVAL;
1713 
1714 	if (data[IFLA_GRE_OKEY] &&
1715 	    (ntohl(nla_get_be32(data[IFLA_GRE_OKEY])) & ~ID_MASK))
1716 		return -EINVAL;
1717 
1718 	if (data[IFLA_GRE_ERSPAN_VER]) {
1719 		ver = nla_get_u8(data[IFLA_GRE_ERSPAN_VER]);
1720 		if (ver != 1 && ver != 2)
1721 			return -EINVAL;
1722 	}
1723 
1724 	if (ver == 1) {
1725 		if (data[IFLA_GRE_ERSPAN_INDEX]) {
1726 			u32 index = nla_get_u32(data[IFLA_GRE_ERSPAN_INDEX]);
1727 
1728 			if (index & ~INDEX_MASK)
1729 				return -EINVAL;
1730 		}
1731 	} else if (ver == 2) {
1732 		if (data[IFLA_GRE_ERSPAN_DIR]) {
1733 			u16 dir = nla_get_u8(data[IFLA_GRE_ERSPAN_DIR]);
1734 
1735 			if (dir & ~(DIR_MASK >> DIR_OFFSET))
1736 				return -EINVAL;
1737 		}
1738 
1739 		if (data[IFLA_GRE_ERSPAN_HWID]) {
1740 			u16 hwid = nla_get_u16(data[IFLA_GRE_ERSPAN_HWID]);
1741 
1742 			if (hwid & ~(HWID_MASK >> HWID_OFFSET))
1743 				return -EINVAL;
1744 		}
1745 	}
1746 
1747 	return 0;
1748 }
1749 
1750 static void ip6erspan_set_version(struct nlattr *data[],
1751 				  struct __ip6_tnl_parm *parms)
1752 {
1753 	if (!data)
1754 		return;
1755 
1756 	parms->erspan_ver = 1;
1757 	if (data[IFLA_GRE_ERSPAN_VER])
1758 		parms->erspan_ver = nla_get_u8(data[IFLA_GRE_ERSPAN_VER]);
1759 
1760 	if (parms->erspan_ver == 1) {
1761 		if (data[IFLA_GRE_ERSPAN_INDEX])
1762 			parms->index = nla_get_u32(data[IFLA_GRE_ERSPAN_INDEX]);
1763 	} else if (parms->erspan_ver == 2) {
1764 		if (data[IFLA_GRE_ERSPAN_DIR])
1765 			parms->dir = nla_get_u8(data[IFLA_GRE_ERSPAN_DIR]);
1766 		if (data[IFLA_GRE_ERSPAN_HWID])
1767 			parms->hwid = nla_get_u16(data[IFLA_GRE_ERSPAN_HWID]);
1768 	}
1769 }
1770 
1771 static void ip6gre_netlink_parms(struct nlattr *data[],
1772 				struct __ip6_tnl_parm *parms)
1773 {
1774 	memset(parms, 0, sizeof(*parms));
1775 
1776 	if (!data)
1777 		return;
1778 
1779 	if (data[IFLA_GRE_LINK])
1780 		parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
1781 
1782 	if (data[IFLA_GRE_IFLAGS])
1783 		parms->i_flags = gre_flags_to_tnl_flags(
1784 				nla_get_be16(data[IFLA_GRE_IFLAGS]));
1785 
1786 	if (data[IFLA_GRE_OFLAGS])
1787 		parms->o_flags = gre_flags_to_tnl_flags(
1788 				nla_get_be16(data[IFLA_GRE_OFLAGS]));
1789 
1790 	if (data[IFLA_GRE_IKEY])
1791 		parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
1792 
1793 	if (data[IFLA_GRE_OKEY])
1794 		parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
1795 
1796 	if (data[IFLA_GRE_LOCAL])
1797 		parms->laddr = nla_get_in6_addr(data[IFLA_GRE_LOCAL]);
1798 
1799 	if (data[IFLA_GRE_REMOTE])
1800 		parms->raddr = nla_get_in6_addr(data[IFLA_GRE_REMOTE]);
1801 
1802 	if (data[IFLA_GRE_TTL])
1803 		parms->hop_limit = nla_get_u8(data[IFLA_GRE_TTL]);
1804 
1805 	if (data[IFLA_GRE_ENCAP_LIMIT])
1806 		parms->encap_limit = nla_get_u8(data[IFLA_GRE_ENCAP_LIMIT]);
1807 
1808 	if (data[IFLA_GRE_FLOWINFO])
1809 		parms->flowinfo = nla_get_be32(data[IFLA_GRE_FLOWINFO]);
1810 
1811 	if (data[IFLA_GRE_FLAGS])
1812 		parms->flags = nla_get_u32(data[IFLA_GRE_FLAGS]);
1813 
1814 	if (data[IFLA_GRE_FWMARK])
1815 		parms->fwmark = nla_get_u32(data[IFLA_GRE_FWMARK]);
1816 
1817 	if (data[IFLA_GRE_COLLECT_METADATA])
1818 		parms->collect_md = true;
1819 }
1820 
1821 static int ip6gre_tap_init(struct net_device *dev)
1822 {
1823 	int ret;
1824 
1825 	ret = ip6gre_tunnel_init_common(dev);
1826 	if (ret)
1827 		return ret;
1828 
1829 	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1830 
1831 	return 0;
1832 }
1833 
1834 static const struct net_device_ops ip6gre_tap_netdev_ops = {
1835 	.ndo_init = ip6gre_tap_init,
1836 	.ndo_uninit = ip6gre_tunnel_uninit,
1837 	.ndo_start_xmit = ip6gre_tunnel_xmit,
1838 	.ndo_set_mac_address = eth_mac_addr,
1839 	.ndo_validate_addr = eth_validate_addr,
1840 	.ndo_change_mtu = ip6_tnl_change_mtu,
1841 	.ndo_get_stats64 = dev_get_tstats64,
1842 	.ndo_get_iflink = ip6_tnl_get_iflink,
1843 };
1844 
1845 static int ip6erspan_calc_hlen(struct ip6_tnl *tunnel)
1846 {
1847 	int t_hlen;
1848 
1849 	tunnel->tun_hlen = 8;
1850 	tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen +
1851 		       erspan_hdr_len(tunnel->parms.erspan_ver);
1852 
1853 	t_hlen = tunnel->hlen + sizeof(struct ipv6hdr);
1854 	tunnel->dev->needed_headroom = LL_MAX_HEADER + t_hlen;
1855 	return t_hlen;
1856 }
1857 
1858 static int ip6erspan_tap_init(struct net_device *dev)
1859 {
1860 	struct ip6_tnl *tunnel;
1861 	int t_hlen;
1862 	int ret;
1863 
1864 	tunnel = netdev_priv(dev);
1865 
1866 	tunnel->dev = dev;
1867 	tunnel->net = dev_net(dev);
1868 	strcpy(tunnel->parms.name, dev->name);
1869 
1870 	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1871 	if (!dev->tstats)
1872 		return -ENOMEM;
1873 
1874 	ret = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL);
1875 	if (ret)
1876 		goto cleanup_alloc_pcpu_stats;
1877 
1878 	ret = gro_cells_init(&tunnel->gro_cells, dev);
1879 	if (ret)
1880 		goto cleanup_dst_cache_init;
1881 
1882 	t_hlen = ip6erspan_calc_hlen(tunnel);
1883 	dev->mtu = ETH_DATA_LEN - t_hlen;
1884 	if (dev->type == ARPHRD_ETHER)
1885 		dev->mtu -= ETH_HLEN;
1886 	if (!(tunnel->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1887 		dev->mtu -= 8;
1888 
1889 	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1890 	ip6erspan_tnl_link_config(tunnel, 1);
1891 
1892 	return 0;
1893 
1894 cleanup_dst_cache_init:
1895 	dst_cache_destroy(&tunnel->dst_cache);
1896 cleanup_alloc_pcpu_stats:
1897 	free_percpu(dev->tstats);
1898 	dev->tstats = NULL;
1899 	return ret;
1900 }
1901 
1902 static const struct net_device_ops ip6erspan_netdev_ops = {
1903 	.ndo_init =		ip6erspan_tap_init,
1904 	.ndo_uninit =		ip6erspan_tunnel_uninit,
1905 	.ndo_start_xmit =	ip6erspan_tunnel_xmit,
1906 	.ndo_set_mac_address =	eth_mac_addr,
1907 	.ndo_validate_addr =	eth_validate_addr,
1908 	.ndo_change_mtu =	ip6_tnl_change_mtu,
1909 	.ndo_get_stats64 =	dev_get_tstats64,
1910 	.ndo_get_iflink =	ip6_tnl_get_iflink,
1911 };
1912 
1913 static void ip6gre_tap_setup(struct net_device *dev)
1914 {
1915 
1916 	ether_setup(dev);
1917 
1918 	dev->max_mtu = 0;
1919 	dev->netdev_ops = &ip6gre_tap_netdev_ops;
1920 	dev->needs_free_netdev = true;
1921 	dev->priv_destructor = ip6gre_dev_free;
1922 
1923 	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1924 	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1925 	netif_keep_dst(dev);
1926 }
1927 
1928 static bool ip6gre_netlink_encap_parms(struct nlattr *data[],
1929 				       struct ip_tunnel_encap *ipencap)
1930 {
1931 	bool ret = false;
1932 
1933 	memset(ipencap, 0, sizeof(*ipencap));
1934 
1935 	if (!data)
1936 		return ret;
1937 
1938 	if (data[IFLA_GRE_ENCAP_TYPE]) {
1939 		ret = true;
1940 		ipencap->type = nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]);
1941 	}
1942 
1943 	if (data[IFLA_GRE_ENCAP_FLAGS]) {
1944 		ret = true;
1945 		ipencap->flags = nla_get_u16(data[IFLA_GRE_ENCAP_FLAGS]);
1946 	}
1947 
1948 	if (data[IFLA_GRE_ENCAP_SPORT]) {
1949 		ret = true;
1950 		ipencap->sport = nla_get_be16(data[IFLA_GRE_ENCAP_SPORT]);
1951 	}
1952 
1953 	if (data[IFLA_GRE_ENCAP_DPORT]) {
1954 		ret = true;
1955 		ipencap->dport = nla_get_be16(data[IFLA_GRE_ENCAP_DPORT]);
1956 	}
1957 
1958 	return ret;
1959 }
1960 
1961 static int ip6gre_newlink_common(struct net *src_net, struct net_device *dev,
1962 				 struct nlattr *tb[], struct nlattr *data[],
1963 				 struct netlink_ext_ack *extack)
1964 {
1965 	struct ip6_tnl *nt;
1966 	struct ip_tunnel_encap ipencap;
1967 	int err;
1968 
1969 	nt = netdev_priv(dev);
1970 
1971 	if (ip6gre_netlink_encap_parms(data, &ipencap)) {
1972 		int err = ip6_tnl_encap_setup(nt, &ipencap);
1973 
1974 		if (err < 0)
1975 			return err;
1976 	}
1977 
1978 	if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
1979 		eth_hw_addr_random(dev);
1980 
1981 	nt->dev = dev;
1982 	nt->net = dev_net(dev);
1983 
1984 	err = register_netdevice(dev);
1985 	if (err)
1986 		goto out;
1987 
1988 	if (tb[IFLA_MTU])
1989 		ip6_tnl_change_mtu(dev, nla_get_u32(tb[IFLA_MTU]));
1990 
1991 	dev_hold(dev);
1992 
1993 out:
1994 	return err;
1995 }
1996 
1997 static int ip6gre_newlink(struct net *src_net, struct net_device *dev,
1998 			  struct nlattr *tb[], struct nlattr *data[],
1999 			  struct netlink_ext_ack *extack)
2000 {
2001 	struct ip6_tnl *nt = netdev_priv(dev);
2002 	struct net *net = dev_net(dev);
2003 	struct ip6gre_net *ign;
2004 	int err;
2005 
2006 	ip6gre_netlink_parms(data, &nt->parms);
2007 	ign = net_generic(net, ip6gre_net_id);
2008 
2009 	if (nt->parms.collect_md) {
2010 		if (rtnl_dereference(ign->collect_md_tun))
2011 			return -EEXIST;
2012 	} else {
2013 		if (ip6gre_tunnel_find(net, &nt->parms, dev->type))
2014 			return -EEXIST;
2015 	}
2016 
2017 	err = ip6gre_newlink_common(src_net, dev, tb, data, extack);
2018 	if (!err) {
2019 		ip6gre_tnl_link_config(nt, !tb[IFLA_MTU]);
2020 		ip6gre_tunnel_link_md(ign, nt);
2021 		ip6gre_tunnel_link(net_generic(net, ip6gre_net_id), nt);
2022 	}
2023 	return err;
2024 }
2025 
2026 static struct ip6_tnl *
2027 ip6gre_changelink_common(struct net_device *dev, struct nlattr *tb[],
2028 			 struct nlattr *data[], struct __ip6_tnl_parm *p_p,
2029 			 struct netlink_ext_ack *extack)
2030 {
2031 	struct ip6_tnl *t, *nt = netdev_priv(dev);
2032 	struct net *net = nt->net;
2033 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
2034 	struct ip_tunnel_encap ipencap;
2035 
2036 	if (dev == ign->fb_tunnel_dev)
2037 		return ERR_PTR(-EINVAL);
2038 
2039 	if (ip6gre_netlink_encap_parms(data, &ipencap)) {
2040 		int err = ip6_tnl_encap_setup(nt, &ipencap);
2041 
2042 		if (err < 0)
2043 			return ERR_PTR(err);
2044 	}
2045 
2046 	ip6gre_netlink_parms(data, p_p);
2047 
2048 	t = ip6gre_tunnel_locate(net, p_p, 0);
2049 
2050 	if (t) {
2051 		if (t->dev != dev)
2052 			return ERR_PTR(-EEXIST);
2053 	} else {
2054 		t = nt;
2055 	}
2056 
2057 	return t;
2058 }
2059 
2060 static int ip6gre_changelink(struct net_device *dev, struct nlattr *tb[],
2061 			     struct nlattr *data[],
2062 			     struct netlink_ext_ack *extack)
2063 {
2064 	struct ip6_tnl *t = netdev_priv(dev);
2065 	struct ip6gre_net *ign = net_generic(t->net, ip6gre_net_id);
2066 	struct __ip6_tnl_parm p;
2067 
2068 	t = ip6gre_changelink_common(dev, tb, data, &p, extack);
2069 	if (IS_ERR(t))
2070 		return PTR_ERR(t);
2071 
2072 	ip6gre_tunnel_unlink_md(ign, t);
2073 	ip6gre_tunnel_unlink(ign, t);
2074 	ip6gre_tnl_change(t, &p, !tb[IFLA_MTU]);
2075 	ip6gre_tunnel_link_md(ign, t);
2076 	ip6gre_tunnel_link(ign, t);
2077 	return 0;
2078 }
2079 
2080 static void ip6gre_dellink(struct net_device *dev, struct list_head *head)
2081 {
2082 	struct net *net = dev_net(dev);
2083 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
2084 
2085 	if (dev != ign->fb_tunnel_dev)
2086 		unregister_netdevice_queue(dev, head);
2087 }
2088 
2089 static size_t ip6gre_get_size(const struct net_device *dev)
2090 {
2091 	return
2092 		/* IFLA_GRE_LINK */
2093 		nla_total_size(4) +
2094 		/* IFLA_GRE_IFLAGS */
2095 		nla_total_size(2) +
2096 		/* IFLA_GRE_OFLAGS */
2097 		nla_total_size(2) +
2098 		/* IFLA_GRE_IKEY */
2099 		nla_total_size(4) +
2100 		/* IFLA_GRE_OKEY */
2101 		nla_total_size(4) +
2102 		/* IFLA_GRE_LOCAL */
2103 		nla_total_size(sizeof(struct in6_addr)) +
2104 		/* IFLA_GRE_REMOTE */
2105 		nla_total_size(sizeof(struct in6_addr)) +
2106 		/* IFLA_GRE_TTL */
2107 		nla_total_size(1) +
2108 		/* IFLA_GRE_ENCAP_LIMIT */
2109 		nla_total_size(1) +
2110 		/* IFLA_GRE_FLOWINFO */
2111 		nla_total_size(4) +
2112 		/* IFLA_GRE_FLAGS */
2113 		nla_total_size(4) +
2114 		/* IFLA_GRE_ENCAP_TYPE */
2115 		nla_total_size(2) +
2116 		/* IFLA_GRE_ENCAP_FLAGS */
2117 		nla_total_size(2) +
2118 		/* IFLA_GRE_ENCAP_SPORT */
2119 		nla_total_size(2) +
2120 		/* IFLA_GRE_ENCAP_DPORT */
2121 		nla_total_size(2) +
2122 		/* IFLA_GRE_COLLECT_METADATA */
2123 		nla_total_size(0) +
2124 		/* IFLA_GRE_FWMARK */
2125 		nla_total_size(4) +
2126 		/* IFLA_GRE_ERSPAN_INDEX */
2127 		nla_total_size(4) +
2128 		0;
2129 }
2130 
2131 static int ip6gre_fill_info(struct sk_buff *skb, const struct net_device *dev)
2132 {
2133 	struct ip6_tnl *t = netdev_priv(dev);
2134 	struct __ip6_tnl_parm *p = &t->parms;
2135 	__be16 o_flags = p->o_flags;
2136 
2137 	if (p->erspan_ver == 1 || p->erspan_ver == 2) {
2138 		if (!p->collect_md)
2139 			o_flags |= TUNNEL_KEY;
2140 
2141 		if (nla_put_u8(skb, IFLA_GRE_ERSPAN_VER, p->erspan_ver))
2142 			goto nla_put_failure;
2143 
2144 		if (p->erspan_ver == 1) {
2145 			if (nla_put_u32(skb, IFLA_GRE_ERSPAN_INDEX, p->index))
2146 				goto nla_put_failure;
2147 		} else {
2148 			if (nla_put_u8(skb, IFLA_GRE_ERSPAN_DIR, p->dir))
2149 				goto nla_put_failure;
2150 			if (nla_put_u16(skb, IFLA_GRE_ERSPAN_HWID, p->hwid))
2151 				goto nla_put_failure;
2152 		}
2153 	}
2154 
2155 	if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
2156 	    nla_put_be16(skb, IFLA_GRE_IFLAGS,
2157 			 gre_tnl_flags_to_gre_flags(p->i_flags)) ||
2158 	    nla_put_be16(skb, IFLA_GRE_OFLAGS,
2159 			 gre_tnl_flags_to_gre_flags(o_flags)) ||
2160 	    nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
2161 	    nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
2162 	    nla_put_in6_addr(skb, IFLA_GRE_LOCAL, &p->laddr) ||
2163 	    nla_put_in6_addr(skb, IFLA_GRE_REMOTE, &p->raddr) ||
2164 	    nla_put_u8(skb, IFLA_GRE_TTL, p->hop_limit) ||
2165 	    nla_put_u8(skb, IFLA_GRE_ENCAP_LIMIT, p->encap_limit) ||
2166 	    nla_put_be32(skb, IFLA_GRE_FLOWINFO, p->flowinfo) ||
2167 	    nla_put_u32(skb, IFLA_GRE_FLAGS, p->flags) ||
2168 	    nla_put_u32(skb, IFLA_GRE_FWMARK, p->fwmark))
2169 		goto nla_put_failure;
2170 
2171 	if (nla_put_u16(skb, IFLA_GRE_ENCAP_TYPE,
2172 			t->encap.type) ||
2173 	    nla_put_be16(skb, IFLA_GRE_ENCAP_SPORT,
2174 			 t->encap.sport) ||
2175 	    nla_put_be16(skb, IFLA_GRE_ENCAP_DPORT,
2176 			 t->encap.dport) ||
2177 	    nla_put_u16(skb, IFLA_GRE_ENCAP_FLAGS,
2178 			t->encap.flags))
2179 		goto nla_put_failure;
2180 
2181 	if (p->collect_md) {
2182 		if (nla_put_flag(skb, IFLA_GRE_COLLECT_METADATA))
2183 			goto nla_put_failure;
2184 	}
2185 
2186 	return 0;
2187 
2188 nla_put_failure:
2189 	return -EMSGSIZE;
2190 }
2191 
2192 static const struct nla_policy ip6gre_policy[IFLA_GRE_MAX + 1] = {
2193 	[IFLA_GRE_LINK]        = { .type = NLA_U32 },
2194 	[IFLA_GRE_IFLAGS]      = { .type = NLA_U16 },
2195 	[IFLA_GRE_OFLAGS]      = { .type = NLA_U16 },
2196 	[IFLA_GRE_IKEY]        = { .type = NLA_U32 },
2197 	[IFLA_GRE_OKEY]        = { .type = NLA_U32 },
2198 	[IFLA_GRE_LOCAL]       = { .len = sizeof_field(struct ipv6hdr, saddr) },
2199 	[IFLA_GRE_REMOTE]      = { .len = sizeof_field(struct ipv6hdr, daddr) },
2200 	[IFLA_GRE_TTL]         = { .type = NLA_U8 },
2201 	[IFLA_GRE_ENCAP_LIMIT] = { .type = NLA_U8 },
2202 	[IFLA_GRE_FLOWINFO]    = { .type = NLA_U32 },
2203 	[IFLA_GRE_FLAGS]       = { .type = NLA_U32 },
2204 	[IFLA_GRE_ENCAP_TYPE]   = { .type = NLA_U16 },
2205 	[IFLA_GRE_ENCAP_FLAGS]  = { .type = NLA_U16 },
2206 	[IFLA_GRE_ENCAP_SPORT]  = { .type = NLA_U16 },
2207 	[IFLA_GRE_ENCAP_DPORT]  = { .type = NLA_U16 },
2208 	[IFLA_GRE_COLLECT_METADATA] = { .type = NLA_FLAG },
2209 	[IFLA_GRE_FWMARK]       = { .type = NLA_U32 },
2210 	[IFLA_GRE_ERSPAN_INDEX] = { .type = NLA_U32 },
2211 	[IFLA_GRE_ERSPAN_VER]	= { .type = NLA_U8 },
2212 	[IFLA_GRE_ERSPAN_DIR]	= { .type = NLA_U8 },
2213 	[IFLA_GRE_ERSPAN_HWID]	= { .type = NLA_U16 },
2214 };
2215 
2216 static void ip6erspan_tap_setup(struct net_device *dev)
2217 {
2218 	ether_setup(dev);
2219 
2220 	dev->max_mtu = 0;
2221 	dev->netdev_ops = &ip6erspan_netdev_ops;
2222 	dev->needs_free_netdev = true;
2223 	dev->priv_destructor = ip6gre_dev_free;
2224 
2225 	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
2226 	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
2227 	netif_keep_dst(dev);
2228 }
2229 
2230 static int ip6erspan_newlink(struct net *src_net, struct net_device *dev,
2231 			     struct nlattr *tb[], struct nlattr *data[],
2232 			     struct netlink_ext_ack *extack)
2233 {
2234 	struct ip6_tnl *nt = netdev_priv(dev);
2235 	struct net *net = dev_net(dev);
2236 	struct ip6gre_net *ign;
2237 	int err;
2238 
2239 	ip6gre_netlink_parms(data, &nt->parms);
2240 	ip6erspan_set_version(data, &nt->parms);
2241 	ign = net_generic(net, ip6gre_net_id);
2242 
2243 	if (nt->parms.collect_md) {
2244 		if (rtnl_dereference(ign->collect_md_tun_erspan))
2245 			return -EEXIST;
2246 	} else {
2247 		if (ip6gre_tunnel_find(net, &nt->parms, dev->type))
2248 			return -EEXIST;
2249 	}
2250 
2251 	err = ip6gre_newlink_common(src_net, dev, tb, data, extack);
2252 	if (!err) {
2253 		ip6erspan_tnl_link_config(nt, !tb[IFLA_MTU]);
2254 		ip6erspan_tunnel_link_md(ign, nt);
2255 		ip6gre_tunnel_link(net_generic(net, ip6gre_net_id), nt);
2256 	}
2257 	return err;
2258 }
2259 
2260 static void ip6erspan_tnl_link_config(struct ip6_tnl *t, int set_mtu)
2261 {
2262 	ip6gre_tnl_link_config_common(t);
2263 	ip6gre_tnl_link_config_route(t, set_mtu, ip6erspan_calc_hlen(t));
2264 }
2265 
2266 static int ip6erspan_tnl_change(struct ip6_tnl *t,
2267 				const struct __ip6_tnl_parm *p, int set_mtu)
2268 {
2269 	ip6gre_tnl_copy_tnl_parm(t, p);
2270 	ip6erspan_tnl_link_config(t, set_mtu);
2271 	return 0;
2272 }
2273 
2274 static int ip6erspan_changelink(struct net_device *dev, struct nlattr *tb[],
2275 				struct nlattr *data[],
2276 				struct netlink_ext_ack *extack)
2277 {
2278 	struct ip6gre_net *ign = net_generic(dev_net(dev), ip6gre_net_id);
2279 	struct __ip6_tnl_parm p;
2280 	struct ip6_tnl *t;
2281 
2282 	t = ip6gre_changelink_common(dev, tb, data, &p, extack);
2283 	if (IS_ERR(t))
2284 		return PTR_ERR(t);
2285 
2286 	ip6erspan_set_version(data, &p);
2287 	ip6gre_tunnel_unlink_md(ign, t);
2288 	ip6gre_tunnel_unlink(ign, t);
2289 	ip6erspan_tnl_change(t, &p, !tb[IFLA_MTU]);
2290 	ip6erspan_tunnel_link_md(ign, t);
2291 	ip6gre_tunnel_link(ign, t);
2292 	return 0;
2293 }
2294 
2295 static struct rtnl_link_ops ip6gre_link_ops __read_mostly = {
2296 	.kind		= "ip6gre",
2297 	.maxtype	= IFLA_GRE_MAX,
2298 	.policy		= ip6gre_policy,
2299 	.priv_size	= sizeof(struct ip6_tnl),
2300 	.setup		= ip6gre_tunnel_setup,
2301 	.validate	= ip6gre_tunnel_validate,
2302 	.newlink	= ip6gre_newlink,
2303 	.changelink	= ip6gre_changelink,
2304 	.dellink	= ip6gre_dellink,
2305 	.get_size	= ip6gre_get_size,
2306 	.fill_info	= ip6gre_fill_info,
2307 	.get_link_net	= ip6_tnl_get_link_net,
2308 };
2309 
2310 static struct rtnl_link_ops ip6gre_tap_ops __read_mostly = {
2311 	.kind		= "ip6gretap",
2312 	.maxtype	= IFLA_GRE_MAX,
2313 	.policy		= ip6gre_policy,
2314 	.priv_size	= sizeof(struct ip6_tnl),
2315 	.setup		= ip6gre_tap_setup,
2316 	.validate	= ip6gre_tap_validate,
2317 	.newlink	= ip6gre_newlink,
2318 	.changelink	= ip6gre_changelink,
2319 	.get_size	= ip6gre_get_size,
2320 	.fill_info	= ip6gre_fill_info,
2321 	.get_link_net	= ip6_tnl_get_link_net,
2322 };
2323 
2324 static struct rtnl_link_ops ip6erspan_tap_ops __read_mostly = {
2325 	.kind		= "ip6erspan",
2326 	.maxtype	= IFLA_GRE_MAX,
2327 	.policy		= ip6gre_policy,
2328 	.priv_size	= sizeof(struct ip6_tnl),
2329 	.setup		= ip6erspan_tap_setup,
2330 	.validate	= ip6erspan_tap_validate,
2331 	.newlink	= ip6erspan_newlink,
2332 	.changelink	= ip6erspan_changelink,
2333 	.get_size	= ip6gre_get_size,
2334 	.fill_info	= ip6gre_fill_info,
2335 	.get_link_net	= ip6_tnl_get_link_net,
2336 };
2337 
2338 /*
2339  *	And now the modules code and kernel interface.
2340  */
2341 
2342 static int __init ip6gre_init(void)
2343 {
2344 	int err;
2345 
2346 	pr_info("GRE over IPv6 tunneling driver\n");
2347 
2348 	err = register_pernet_device(&ip6gre_net_ops);
2349 	if (err < 0)
2350 		return err;
2351 
2352 	err = inet6_add_protocol(&ip6gre_protocol, IPPROTO_GRE);
2353 	if (err < 0) {
2354 		pr_info("%s: can't add protocol\n", __func__);
2355 		goto add_proto_failed;
2356 	}
2357 
2358 	err = rtnl_link_register(&ip6gre_link_ops);
2359 	if (err < 0)
2360 		goto rtnl_link_failed;
2361 
2362 	err = rtnl_link_register(&ip6gre_tap_ops);
2363 	if (err < 0)
2364 		goto tap_ops_failed;
2365 
2366 	err = rtnl_link_register(&ip6erspan_tap_ops);
2367 	if (err < 0)
2368 		goto erspan_link_failed;
2369 
2370 out:
2371 	return err;
2372 
2373 erspan_link_failed:
2374 	rtnl_link_unregister(&ip6gre_tap_ops);
2375 tap_ops_failed:
2376 	rtnl_link_unregister(&ip6gre_link_ops);
2377 rtnl_link_failed:
2378 	inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
2379 add_proto_failed:
2380 	unregister_pernet_device(&ip6gre_net_ops);
2381 	goto out;
2382 }
2383 
2384 static void __exit ip6gre_fini(void)
2385 {
2386 	rtnl_link_unregister(&ip6gre_tap_ops);
2387 	rtnl_link_unregister(&ip6gre_link_ops);
2388 	rtnl_link_unregister(&ip6erspan_tap_ops);
2389 	inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
2390 	unregister_pernet_device(&ip6gre_net_ops);
2391 }
2392 
2393 module_init(ip6gre_init);
2394 module_exit(ip6gre_fini);
2395 MODULE_LICENSE("GPL");
2396 MODULE_AUTHOR("D. Kozlov (xeb@mail.ru)");
2397 MODULE_DESCRIPTION("GRE over IPv6 tunneling device");
2398 MODULE_ALIAS_RTNL_LINK("ip6gre");
2399 MODULE_ALIAS_RTNL_LINK("ip6gretap");
2400 MODULE_ALIAS_RTNL_LINK("ip6erspan");
2401 MODULE_ALIAS_NETDEV("ip6gre0");
2402