xref: /openbmc/linux/net/ipv6/ip6_gre.c (revision ada066b2)
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 	ip6gre_tunnel_link(ign, nt);
391 	return nt;
392 
393 failed_free:
394 	free_netdev(dev);
395 	return NULL;
396 }
397 
398 static void ip6erspan_tunnel_uninit(struct net_device *dev)
399 {
400 	struct ip6_tnl *t = netdev_priv(dev);
401 	struct ip6gre_net *ign = net_generic(t->net, ip6gre_net_id);
402 
403 	ip6erspan_tunnel_unlink_md(ign, t);
404 	ip6gre_tunnel_unlink(ign, t);
405 	dst_cache_reset(&t->dst_cache);
406 	dev_put_track(dev, &t->dev_tracker);
407 }
408 
409 static void ip6gre_tunnel_uninit(struct net_device *dev)
410 {
411 	struct ip6_tnl *t = netdev_priv(dev);
412 	struct ip6gre_net *ign = net_generic(t->net, ip6gre_net_id);
413 
414 	ip6gre_tunnel_unlink_md(ign, t);
415 	ip6gre_tunnel_unlink(ign, t);
416 	if (ign->fb_tunnel_dev == dev)
417 		WRITE_ONCE(ign->fb_tunnel_dev, NULL);
418 	dst_cache_reset(&t->dst_cache);
419 	dev_put_track(dev, &t->dev_tracker);
420 }
421 
422 
423 static int ip6gre_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
424 		       u8 type, u8 code, int offset, __be32 info)
425 {
426 	struct net *net = dev_net(skb->dev);
427 	const struct ipv6hdr *ipv6h;
428 	struct tnl_ptk_info tpi;
429 	struct ip6_tnl *t;
430 
431 	if (gre_parse_header(skb, &tpi, NULL, htons(ETH_P_IPV6),
432 			     offset) < 0)
433 		return -EINVAL;
434 
435 	ipv6h = (const struct ipv6hdr *)skb->data;
436 	t = ip6gre_tunnel_lookup(skb->dev, &ipv6h->daddr, &ipv6h->saddr,
437 				 tpi.key, tpi.proto);
438 	if (!t)
439 		return -ENOENT;
440 
441 	switch (type) {
442 	case ICMPV6_DEST_UNREACH:
443 		net_dbg_ratelimited("%s: Path to destination invalid or inactive!\n",
444 				    t->parms.name);
445 		if (code != ICMPV6_PORT_UNREACH)
446 			break;
447 		return 0;
448 	case ICMPV6_TIME_EXCEED:
449 		if (code == ICMPV6_EXC_HOPLIMIT) {
450 			net_dbg_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
451 					    t->parms.name);
452 			break;
453 		}
454 		return 0;
455 	case ICMPV6_PARAMPROB: {
456 		struct ipv6_tlv_tnl_enc_lim *tel;
457 		__u32 teli;
458 
459 		teli = 0;
460 		if (code == ICMPV6_HDR_FIELD)
461 			teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
462 
463 		if (teli && teli == be32_to_cpu(info) - 2) {
464 			tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
465 			if (tel->encap_limit == 0) {
466 				net_dbg_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
467 						    t->parms.name);
468 			}
469 		} else {
470 			net_dbg_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
471 					    t->parms.name);
472 		}
473 		return 0;
474 	}
475 	case ICMPV6_PKT_TOOBIG:
476 		ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL));
477 		return 0;
478 	case NDISC_REDIRECT:
479 		ip6_redirect(skb, net, skb->dev->ifindex, 0,
480 			     sock_net_uid(net, NULL));
481 		return 0;
482 	}
483 
484 	if (time_before(jiffies, t->err_time + IP6TUNNEL_ERR_TIMEO))
485 		t->err_count++;
486 	else
487 		t->err_count = 1;
488 	t->err_time = jiffies;
489 
490 	return 0;
491 }
492 
493 static int ip6gre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi)
494 {
495 	const struct ipv6hdr *ipv6h;
496 	struct ip6_tnl *tunnel;
497 
498 	ipv6h = ipv6_hdr(skb);
499 	tunnel = ip6gre_tunnel_lookup(skb->dev,
500 				      &ipv6h->saddr, &ipv6h->daddr, tpi->key,
501 				      tpi->proto);
502 	if (tunnel) {
503 		if (tunnel->parms.collect_md) {
504 			struct metadata_dst *tun_dst;
505 			__be64 tun_id;
506 			__be16 flags;
507 
508 			flags = tpi->flags;
509 			tun_id = key32_to_tunnel_id(tpi->key);
510 
511 			tun_dst = ipv6_tun_rx_dst(skb, flags, tun_id, 0);
512 			if (!tun_dst)
513 				return PACKET_REJECT;
514 
515 			ip6_tnl_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error);
516 		} else {
517 			ip6_tnl_rcv(tunnel, skb, tpi, NULL, log_ecn_error);
518 		}
519 
520 		return PACKET_RCVD;
521 	}
522 
523 	return PACKET_REJECT;
524 }
525 
526 static int ip6erspan_rcv(struct sk_buff *skb,
527 			 struct tnl_ptk_info *tpi,
528 			 int gre_hdr_len)
529 {
530 	struct erspan_base_hdr *ershdr;
531 	const struct ipv6hdr *ipv6h;
532 	struct erspan_md2 *md2;
533 	struct ip6_tnl *tunnel;
534 	u8 ver;
535 
536 	ipv6h = ipv6_hdr(skb);
537 	ershdr = (struct erspan_base_hdr *)skb->data;
538 	ver = ershdr->ver;
539 
540 	tunnel = ip6gre_tunnel_lookup(skb->dev,
541 				      &ipv6h->saddr, &ipv6h->daddr, tpi->key,
542 				      tpi->proto);
543 	if (tunnel) {
544 		int len = erspan_hdr_len(ver);
545 
546 		if (unlikely(!pskb_may_pull(skb, len)))
547 			return PACKET_REJECT;
548 
549 		if (__iptunnel_pull_header(skb, len,
550 					   htons(ETH_P_TEB),
551 					   false, false) < 0)
552 			return PACKET_REJECT;
553 
554 		if (tunnel->parms.collect_md) {
555 			struct erspan_metadata *pkt_md, *md;
556 			struct metadata_dst *tun_dst;
557 			struct ip_tunnel_info *info;
558 			unsigned char *gh;
559 			__be64 tun_id;
560 			__be16 flags;
561 
562 			tpi->flags |= TUNNEL_KEY;
563 			flags = tpi->flags;
564 			tun_id = key32_to_tunnel_id(tpi->key);
565 
566 			tun_dst = ipv6_tun_rx_dst(skb, flags, tun_id,
567 						  sizeof(*md));
568 			if (!tun_dst)
569 				return PACKET_REJECT;
570 
571 			/* skb can be uncloned in __iptunnel_pull_header, so
572 			 * old pkt_md is no longer valid and we need to reset
573 			 * it
574 			 */
575 			gh = skb_network_header(skb) +
576 			     skb_network_header_len(skb);
577 			pkt_md = (struct erspan_metadata *)(gh + gre_hdr_len +
578 							    sizeof(*ershdr));
579 			info = &tun_dst->u.tun_info;
580 			md = ip_tunnel_info_opts(info);
581 			md->version = ver;
582 			md2 = &md->u.md2;
583 			memcpy(md2, pkt_md, ver == 1 ? ERSPAN_V1_MDSIZE :
584 						       ERSPAN_V2_MDSIZE);
585 			info->key.tun_flags |= TUNNEL_ERSPAN_OPT;
586 			info->options_len = sizeof(*md);
587 
588 			ip6_tnl_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error);
589 
590 		} else {
591 			ip6_tnl_rcv(tunnel, skb, tpi, NULL, log_ecn_error);
592 		}
593 
594 		return PACKET_RCVD;
595 	}
596 
597 	return PACKET_REJECT;
598 }
599 
600 static int gre_rcv(struct sk_buff *skb)
601 {
602 	struct tnl_ptk_info tpi;
603 	bool csum_err = false;
604 	int hdr_len;
605 
606 	hdr_len = gre_parse_header(skb, &tpi, &csum_err, htons(ETH_P_IPV6), 0);
607 	if (hdr_len < 0)
608 		goto drop;
609 
610 	if (iptunnel_pull_header(skb, hdr_len, tpi.proto, false))
611 		goto drop;
612 
613 	if (unlikely(tpi.proto == htons(ETH_P_ERSPAN) ||
614 		     tpi.proto == htons(ETH_P_ERSPAN2))) {
615 		if (ip6erspan_rcv(skb, &tpi, hdr_len) == PACKET_RCVD)
616 			return 0;
617 		goto out;
618 	}
619 
620 	if (ip6gre_rcv(skb, &tpi) == PACKET_RCVD)
621 		return 0;
622 
623 out:
624 	icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
625 drop:
626 	kfree_skb(skb);
627 	return 0;
628 }
629 
630 static int gre_handle_offloads(struct sk_buff *skb, bool csum)
631 {
632 	return iptunnel_handle_offloads(skb,
633 					csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE);
634 }
635 
636 static void prepare_ip6gre_xmit_ipv4(struct sk_buff *skb,
637 				     struct net_device *dev,
638 				     struct flowi6 *fl6, __u8 *dsfield,
639 				     int *encap_limit)
640 {
641 	const struct iphdr *iph = ip_hdr(skb);
642 	struct ip6_tnl *t = netdev_priv(dev);
643 
644 	if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
645 		*encap_limit = t->parms.encap_limit;
646 
647 	memcpy(fl6, &t->fl.u.ip6, sizeof(*fl6));
648 
649 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
650 		*dsfield = ipv4_get_dsfield(iph);
651 	else
652 		*dsfield = ip6_tclass(t->parms.flowinfo);
653 
654 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
655 		fl6->flowi6_mark = skb->mark;
656 	else
657 		fl6->flowi6_mark = t->parms.fwmark;
658 
659 	fl6->flowi6_uid = sock_net_uid(dev_net(dev), NULL);
660 }
661 
662 static int prepare_ip6gre_xmit_ipv6(struct sk_buff *skb,
663 				    struct net_device *dev,
664 				    struct flowi6 *fl6, __u8 *dsfield,
665 				    int *encap_limit)
666 {
667 	struct ipv6hdr *ipv6h;
668 	struct ip6_tnl *t = netdev_priv(dev);
669 	__u16 offset;
670 
671 	offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
672 	/* ip6_tnl_parse_tlv_enc_lim() might have reallocated skb->head */
673 	ipv6h = ipv6_hdr(skb);
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_ndo_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 struct ip_tunnel_info *skb_tunnel_info_txcheck(struct sk_buff *skb)
710 {
711 	struct ip_tunnel_info *tun_info;
712 
713 	tun_info = skb_tunnel_info(skb);
714 	if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX)))
715 		return ERR_PTR(-EINVAL);
716 
717 	return tun_info;
718 }
719 
720 static netdev_tx_t __gre6_xmit(struct sk_buff *skb,
721 			       struct net_device *dev, __u8 dsfield,
722 			       struct flowi6 *fl6, int encap_limit,
723 			       __u32 *pmtu, __be16 proto)
724 {
725 	struct ip6_tnl *tunnel = netdev_priv(dev);
726 	__be16 protocol;
727 
728 	if (dev->type == ARPHRD_ETHER)
729 		IPCB(skb)->flags = 0;
730 
731 	if (dev->header_ops && dev->type == ARPHRD_IP6GRE)
732 		fl6->daddr = ((struct ipv6hdr *)skb->data)->daddr;
733 	else
734 		fl6->daddr = tunnel->parms.raddr;
735 
736 	if (skb_cow_head(skb, dev->needed_headroom ?: tunnel->hlen))
737 		return -ENOMEM;
738 
739 	/* Push GRE header. */
740 	protocol = (dev->type == ARPHRD_ETHER) ? htons(ETH_P_TEB) : proto;
741 
742 	if (tunnel->parms.collect_md) {
743 		struct ip_tunnel_info *tun_info;
744 		const struct ip_tunnel_key *key;
745 		__be16 flags;
746 
747 		tun_info = skb_tunnel_info_txcheck(skb);
748 		if (IS_ERR(tun_info) ||
749 		    unlikely(ip_tunnel_info_af(tun_info) != AF_INET6))
750 			return -EINVAL;
751 
752 		key = &tun_info->key;
753 		memset(fl6, 0, sizeof(*fl6));
754 		fl6->flowi6_proto = IPPROTO_GRE;
755 		fl6->daddr = key->u.ipv6.dst;
756 		fl6->flowlabel = key->label;
757 		fl6->flowi6_uid = sock_net_uid(dev_net(dev), NULL);
758 
759 		dsfield = key->tos;
760 		flags = key->tun_flags &
761 			(TUNNEL_CSUM | TUNNEL_KEY | TUNNEL_SEQ);
762 		tunnel->tun_hlen = gre_calc_hlen(flags);
763 
764 		gre_build_header(skb, tunnel->tun_hlen,
765 				 flags, protocol,
766 				 tunnel_id_to_key32(tun_info->key.tun_id),
767 				 (flags & TUNNEL_SEQ) ? htonl(tunnel->o_seqno++)
768 						      : 0);
769 
770 	} else {
771 		if (tunnel->parms.o_flags & TUNNEL_SEQ)
772 			tunnel->o_seqno++;
773 
774 		gre_build_header(skb, tunnel->tun_hlen, tunnel->parms.o_flags,
775 				 protocol, tunnel->parms.o_key,
776 				 htonl(tunnel->o_seqno));
777 	}
778 
779 	return ip6_tnl_xmit(skb, dev, dsfield, fl6, encap_limit, pmtu,
780 			    NEXTHDR_GRE);
781 }
782 
783 static inline int ip6gre_xmit_ipv4(struct sk_buff *skb, struct net_device *dev)
784 {
785 	struct ip6_tnl *t = netdev_priv(dev);
786 	int encap_limit = -1;
787 	struct flowi6 fl6;
788 	__u8 dsfield = 0;
789 	__u32 mtu;
790 	int err;
791 
792 	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
793 
794 	if (!t->parms.collect_md)
795 		prepare_ip6gre_xmit_ipv4(skb, dev, &fl6,
796 					 &dsfield, &encap_limit);
797 
798 	err = gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM));
799 	if (err)
800 		return -1;
801 
802 	err = __gre6_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
803 			  skb->protocol);
804 	if (err != 0) {
805 		/* XXX: send ICMP error even if DF is not set. */
806 		if (err == -EMSGSIZE)
807 			icmp_ndo_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
808 				      htonl(mtu));
809 		return -1;
810 	}
811 
812 	return 0;
813 }
814 
815 static inline int ip6gre_xmit_ipv6(struct sk_buff *skb, struct net_device *dev)
816 {
817 	struct ip6_tnl *t = netdev_priv(dev);
818 	struct ipv6hdr *ipv6h = ipv6_hdr(skb);
819 	int encap_limit = -1;
820 	struct flowi6 fl6;
821 	__u8 dsfield = 0;
822 	__u32 mtu;
823 	int err;
824 
825 	if (ipv6_addr_equal(&t->parms.raddr, &ipv6h->saddr))
826 		return -1;
827 
828 	if (!t->parms.collect_md &&
829 	    prepare_ip6gre_xmit_ipv6(skb, dev, &fl6, &dsfield, &encap_limit))
830 		return -1;
831 
832 	if (gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM)))
833 		return -1;
834 
835 	err = __gre6_xmit(skb, dev, dsfield, &fl6, encap_limit,
836 			  &mtu, skb->protocol);
837 	if (err != 0) {
838 		if (err == -EMSGSIZE)
839 			icmpv6_ndo_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
840 		return -1;
841 	}
842 
843 	return 0;
844 }
845 
846 /**
847  * ip6gre_tnl_addr_conflict - compare packet addresses to tunnel's own
848  *   @t: the outgoing tunnel device
849  *   @hdr: IPv6 header from the incoming packet
850  *
851  * Description:
852  *   Avoid trivial tunneling loop by checking that tunnel exit-point
853  *   doesn't match source of incoming packet.
854  *
855  * Return:
856  *   1 if conflict,
857  *   0 else
858  **/
859 
860 static inline bool ip6gre_tnl_addr_conflict(const struct ip6_tnl *t,
861 	const struct ipv6hdr *hdr)
862 {
863 	return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
864 }
865 
866 static int ip6gre_xmit_other(struct sk_buff *skb, struct net_device *dev)
867 {
868 	struct ip6_tnl *t = netdev_priv(dev);
869 	int encap_limit = -1;
870 	struct flowi6 fl6;
871 	__u32 mtu;
872 	int err;
873 
874 	if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
875 		encap_limit = t->parms.encap_limit;
876 
877 	if (!t->parms.collect_md)
878 		memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
879 
880 	err = gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM));
881 	if (err)
882 		return err;
883 
884 	err = __gre6_xmit(skb, dev, 0, &fl6, encap_limit, &mtu, skb->protocol);
885 
886 	return err;
887 }
888 
889 static netdev_tx_t ip6gre_tunnel_xmit(struct sk_buff *skb,
890 	struct net_device *dev)
891 {
892 	struct ip6_tnl *t = netdev_priv(dev);
893 	struct net_device_stats *stats = &t->dev->stats;
894 	int ret;
895 
896 	if (!pskb_inet_may_pull(skb))
897 		goto tx_err;
898 
899 	if (!ip6_tnl_xmit_ctl(t, &t->parms.laddr, &t->parms.raddr))
900 		goto tx_err;
901 
902 	switch (skb->protocol) {
903 	case htons(ETH_P_IP):
904 		ret = ip6gre_xmit_ipv4(skb, dev);
905 		break;
906 	case htons(ETH_P_IPV6):
907 		ret = ip6gre_xmit_ipv6(skb, dev);
908 		break;
909 	default:
910 		ret = ip6gre_xmit_other(skb, dev);
911 		break;
912 	}
913 
914 	if (ret < 0)
915 		goto tx_err;
916 
917 	return NETDEV_TX_OK;
918 
919 tx_err:
920 	if (!t->parms.collect_md || !IS_ERR(skb_tunnel_info_txcheck(skb)))
921 		stats->tx_errors++;
922 	stats->tx_dropped++;
923 	kfree_skb(skb);
924 	return NETDEV_TX_OK;
925 }
926 
927 static netdev_tx_t ip6erspan_tunnel_xmit(struct sk_buff *skb,
928 					 struct net_device *dev)
929 {
930 	struct ip_tunnel_info *tun_info = NULL;
931 	struct ip6_tnl *t = netdev_priv(dev);
932 	struct dst_entry *dst = skb_dst(skb);
933 	struct net_device_stats *stats;
934 	bool truncate = false;
935 	int encap_limit = -1;
936 	__u8 dsfield = false;
937 	struct flowi6 fl6;
938 	int err = -EINVAL;
939 	__be16 proto;
940 	__u32 mtu;
941 	int nhoff;
942 	int thoff;
943 
944 	if (!pskb_inet_may_pull(skb))
945 		goto tx_err;
946 
947 	if (!ip6_tnl_xmit_ctl(t, &t->parms.laddr, &t->parms.raddr))
948 		goto tx_err;
949 
950 	if (gre_handle_offloads(skb, false))
951 		goto tx_err;
952 
953 	if (skb->len > dev->mtu + dev->hard_header_len) {
954 		pskb_trim(skb, dev->mtu + dev->hard_header_len);
955 		truncate = true;
956 	}
957 
958 	nhoff = skb_network_header(skb) - skb_mac_header(skb);
959 	if (skb->protocol == htons(ETH_P_IP) &&
960 	    (ntohs(ip_hdr(skb)->tot_len) > skb->len - nhoff))
961 		truncate = true;
962 
963 	thoff = skb_transport_header(skb) - skb_mac_header(skb);
964 	if (skb->protocol == htons(ETH_P_IPV6) &&
965 	    (ntohs(ipv6_hdr(skb)->payload_len) > skb->len - thoff))
966 		truncate = true;
967 
968 	if (skb_cow_head(skb, dev->needed_headroom ?: t->hlen))
969 		goto tx_err;
970 
971 	t->parms.o_flags &= ~TUNNEL_KEY;
972 	IPCB(skb)->flags = 0;
973 
974 	/* For collect_md mode, derive fl6 from the tunnel key,
975 	 * for native mode, call prepare_ip6gre_xmit_{ipv4,ipv6}.
976 	 */
977 	if (t->parms.collect_md) {
978 		const struct ip_tunnel_key *key;
979 		struct erspan_metadata *md;
980 		__be32 tun_id;
981 
982 		tun_info = skb_tunnel_info_txcheck(skb);
983 		if (IS_ERR(tun_info) ||
984 		    unlikely(ip_tunnel_info_af(tun_info) != AF_INET6))
985 			goto tx_err;
986 
987 		key = &tun_info->key;
988 		memset(&fl6, 0, sizeof(fl6));
989 		fl6.flowi6_proto = IPPROTO_GRE;
990 		fl6.daddr = key->u.ipv6.dst;
991 		fl6.flowlabel = key->label;
992 		fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
993 
994 		dsfield = key->tos;
995 		if (!(tun_info->key.tun_flags & TUNNEL_ERSPAN_OPT))
996 			goto tx_err;
997 		if (tun_info->options_len < sizeof(*md))
998 			goto tx_err;
999 		md = ip_tunnel_info_opts(tun_info);
1000 
1001 		tun_id = tunnel_id_to_key32(key->tun_id);
1002 		if (md->version == 1) {
1003 			erspan_build_header(skb,
1004 					    ntohl(tun_id),
1005 					    ntohl(md->u.index), truncate,
1006 					    false);
1007 		} else if (md->version == 2) {
1008 			erspan_build_header_v2(skb,
1009 					       ntohl(tun_id),
1010 					       md->u.md2.dir,
1011 					       get_hwid(&md->u.md2),
1012 					       truncate, false);
1013 		} else {
1014 			goto tx_err;
1015 		}
1016 	} else {
1017 		switch (skb->protocol) {
1018 		case htons(ETH_P_IP):
1019 			memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1020 			prepare_ip6gre_xmit_ipv4(skb, dev, &fl6,
1021 						 &dsfield, &encap_limit);
1022 			break;
1023 		case htons(ETH_P_IPV6):
1024 			if (ipv6_addr_equal(&t->parms.raddr, &ipv6_hdr(skb)->saddr))
1025 				goto tx_err;
1026 			if (prepare_ip6gre_xmit_ipv6(skb, dev, &fl6,
1027 						     &dsfield, &encap_limit))
1028 				goto tx_err;
1029 			break;
1030 		default:
1031 			memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
1032 			break;
1033 		}
1034 
1035 		if (t->parms.erspan_ver == 1)
1036 			erspan_build_header(skb, ntohl(t->parms.o_key),
1037 					    t->parms.index,
1038 					    truncate, false);
1039 		else if (t->parms.erspan_ver == 2)
1040 			erspan_build_header_v2(skb, ntohl(t->parms.o_key),
1041 					       t->parms.dir,
1042 					       t->parms.hwid,
1043 					       truncate, false);
1044 		else
1045 			goto tx_err;
1046 
1047 		fl6.daddr = t->parms.raddr;
1048 	}
1049 
1050 	/* Push GRE header. */
1051 	proto = (t->parms.erspan_ver == 1) ? htons(ETH_P_ERSPAN)
1052 					   : htons(ETH_P_ERSPAN2);
1053 	gre_build_header(skb, 8, TUNNEL_SEQ, proto, 0, htonl(t->o_seqno++));
1054 
1055 	/* TooBig packet may have updated dst->dev's mtu */
1056 	if (!t->parms.collect_md && dst && dst_mtu(dst) > dst->dev->mtu)
1057 		dst->ops->update_pmtu(dst, NULL, skb, dst->dev->mtu, false);
1058 
1059 	err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
1060 			   NEXTHDR_GRE);
1061 	if (err != 0) {
1062 		/* XXX: send ICMP error even if DF is not set. */
1063 		if (err == -EMSGSIZE) {
1064 			if (skb->protocol == htons(ETH_P_IP))
1065 				icmp_ndo_send(skb, ICMP_DEST_UNREACH,
1066 					      ICMP_FRAG_NEEDED, htonl(mtu));
1067 			else
1068 				icmpv6_ndo_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
1069 		}
1070 
1071 		goto tx_err;
1072 	}
1073 	return NETDEV_TX_OK;
1074 
1075 tx_err:
1076 	stats = &t->dev->stats;
1077 	if (!IS_ERR(tun_info))
1078 		stats->tx_errors++;
1079 	stats->tx_dropped++;
1080 	kfree_skb(skb);
1081 	return NETDEV_TX_OK;
1082 }
1083 
1084 static void ip6gre_tnl_link_config_common(struct ip6_tnl *t)
1085 {
1086 	struct net_device *dev = t->dev;
1087 	struct __ip6_tnl_parm *p = &t->parms;
1088 	struct flowi6 *fl6 = &t->fl.u.ip6;
1089 
1090 	if (dev->type != ARPHRD_ETHER) {
1091 		__dev_addr_set(dev, &p->laddr, sizeof(struct in6_addr));
1092 		memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
1093 	}
1094 
1095 	/* Set up flowi template */
1096 	fl6->saddr = p->laddr;
1097 	fl6->daddr = p->raddr;
1098 	fl6->flowi6_oif = p->link;
1099 	fl6->flowlabel = 0;
1100 	fl6->flowi6_proto = IPPROTO_GRE;
1101 
1102 	if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
1103 		fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
1104 	if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
1105 		fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
1106 
1107 	p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
1108 	p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
1109 
1110 	if (p->flags&IP6_TNL_F_CAP_XMIT &&
1111 			p->flags&IP6_TNL_F_CAP_RCV && dev->type != ARPHRD_ETHER)
1112 		dev->flags |= IFF_POINTOPOINT;
1113 	else
1114 		dev->flags &= ~IFF_POINTOPOINT;
1115 }
1116 
1117 static void ip6gre_tnl_link_config_route(struct ip6_tnl *t, int set_mtu,
1118 					 int t_hlen)
1119 {
1120 	const struct __ip6_tnl_parm *p = &t->parms;
1121 	struct net_device *dev = t->dev;
1122 
1123 	if (p->flags & IP6_TNL_F_CAP_XMIT) {
1124 		int strict = (ipv6_addr_type(&p->raddr) &
1125 			      (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
1126 
1127 		struct rt6_info *rt = rt6_lookup(t->net,
1128 						 &p->raddr, &p->laddr,
1129 						 p->link, NULL, strict);
1130 
1131 		if (!rt)
1132 			return;
1133 
1134 		if (rt->dst.dev) {
1135 			unsigned short dst_len = rt->dst.dev->hard_header_len +
1136 						 t_hlen;
1137 
1138 			if (t->dev->header_ops)
1139 				dev->hard_header_len = dst_len;
1140 			else
1141 				dev->needed_headroom = dst_len;
1142 
1143 			if (set_mtu) {
1144 				dev->mtu = rt->dst.dev->mtu - t_hlen;
1145 				if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1146 					dev->mtu -= 8;
1147 				if (dev->type == ARPHRD_ETHER)
1148 					dev->mtu -= ETH_HLEN;
1149 
1150 				if (dev->mtu < IPV6_MIN_MTU)
1151 					dev->mtu = IPV6_MIN_MTU;
1152 			}
1153 		}
1154 		ip6_rt_put(rt);
1155 	}
1156 }
1157 
1158 static int ip6gre_calc_hlen(struct ip6_tnl *tunnel)
1159 {
1160 	int t_hlen;
1161 
1162 	tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags);
1163 	tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen;
1164 
1165 	t_hlen = tunnel->hlen + sizeof(struct ipv6hdr);
1166 
1167 	if (tunnel->dev->header_ops)
1168 		tunnel->dev->hard_header_len = LL_MAX_HEADER + t_hlen;
1169 	else
1170 		tunnel->dev->needed_headroom = LL_MAX_HEADER + t_hlen;
1171 
1172 	return t_hlen;
1173 }
1174 
1175 static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu)
1176 {
1177 	ip6gre_tnl_link_config_common(t);
1178 	ip6gre_tnl_link_config_route(t, set_mtu, ip6gre_calc_hlen(t));
1179 }
1180 
1181 static void ip6gre_tnl_copy_tnl_parm(struct ip6_tnl *t,
1182 				     const struct __ip6_tnl_parm *p)
1183 {
1184 	t->parms.laddr = p->laddr;
1185 	t->parms.raddr = p->raddr;
1186 	t->parms.flags = p->flags;
1187 	t->parms.hop_limit = p->hop_limit;
1188 	t->parms.encap_limit = p->encap_limit;
1189 	t->parms.flowinfo = p->flowinfo;
1190 	t->parms.link = p->link;
1191 	t->parms.proto = p->proto;
1192 	t->parms.i_key = p->i_key;
1193 	t->parms.o_key = p->o_key;
1194 	t->parms.i_flags = p->i_flags;
1195 	t->parms.o_flags = p->o_flags;
1196 	t->parms.fwmark = p->fwmark;
1197 	t->parms.erspan_ver = p->erspan_ver;
1198 	t->parms.index = p->index;
1199 	t->parms.dir = p->dir;
1200 	t->parms.hwid = p->hwid;
1201 	dst_cache_reset(&t->dst_cache);
1202 }
1203 
1204 static int ip6gre_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p,
1205 			     int set_mtu)
1206 {
1207 	ip6gre_tnl_copy_tnl_parm(t, p);
1208 	ip6gre_tnl_link_config(t, set_mtu);
1209 	return 0;
1210 }
1211 
1212 static void ip6gre_tnl_parm_from_user(struct __ip6_tnl_parm *p,
1213 	const struct ip6_tnl_parm2 *u)
1214 {
1215 	p->laddr = u->laddr;
1216 	p->raddr = u->raddr;
1217 	p->flags = u->flags;
1218 	p->hop_limit = u->hop_limit;
1219 	p->encap_limit = u->encap_limit;
1220 	p->flowinfo = u->flowinfo;
1221 	p->link = u->link;
1222 	p->i_key = u->i_key;
1223 	p->o_key = u->o_key;
1224 	p->i_flags = gre_flags_to_tnl_flags(u->i_flags);
1225 	p->o_flags = gre_flags_to_tnl_flags(u->o_flags);
1226 	memcpy(p->name, u->name, sizeof(u->name));
1227 }
1228 
1229 static void ip6gre_tnl_parm_to_user(struct ip6_tnl_parm2 *u,
1230 	const struct __ip6_tnl_parm *p)
1231 {
1232 	u->proto = IPPROTO_GRE;
1233 	u->laddr = p->laddr;
1234 	u->raddr = p->raddr;
1235 	u->flags = p->flags;
1236 	u->hop_limit = p->hop_limit;
1237 	u->encap_limit = p->encap_limit;
1238 	u->flowinfo = p->flowinfo;
1239 	u->link = p->link;
1240 	u->i_key = p->i_key;
1241 	u->o_key = p->o_key;
1242 	u->i_flags = gre_tnl_flags_to_gre_flags(p->i_flags);
1243 	u->o_flags = gre_tnl_flags_to_gre_flags(p->o_flags);
1244 	memcpy(u->name, p->name, sizeof(u->name));
1245 }
1246 
1247 static int ip6gre_tunnel_siocdevprivate(struct net_device *dev,
1248 					struct ifreq *ifr, void __user *data,
1249 					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, 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(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, 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(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, 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_siocdevprivate	= ip6gre_tunnel_siocdevprivate,
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 	dev_hold_track(dev, &tunnel->dev_tracker, GFP_KERNEL);
1500 	return 0;
1501 
1502 cleanup_dst_cache_init:
1503 	dst_cache_destroy(&tunnel->dst_cache);
1504 cleanup_alloc_pcpu_stats:
1505 	free_percpu(dev->tstats);
1506 	dev->tstats = NULL;
1507 	return ret;
1508 }
1509 
1510 static int ip6gre_tunnel_init(struct net_device *dev)
1511 {
1512 	struct ip6_tnl *tunnel;
1513 	int ret;
1514 
1515 	ret = ip6gre_tunnel_init_common(dev);
1516 	if (ret)
1517 		return ret;
1518 
1519 	tunnel = netdev_priv(dev);
1520 
1521 	if (tunnel->parms.collect_md)
1522 		return 0;
1523 
1524 	__dev_addr_set(dev, &tunnel->parms.laddr, sizeof(struct in6_addr));
1525 	memcpy(dev->broadcast, &tunnel->parms.raddr, sizeof(struct in6_addr));
1526 
1527 	if (ipv6_addr_any(&tunnel->parms.raddr))
1528 		dev->header_ops = &ip6gre_header_ops;
1529 
1530 	return 0;
1531 }
1532 
1533 static void ip6gre_fb_tunnel_init(struct net_device *dev)
1534 {
1535 	struct ip6_tnl *tunnel = netdev_priv(dev);
1536 
1537 	tunnel->dev = dev;
1538 	tunnel->net = dev_net(dev);
1539 	strcpy(tunnel->parms.name, dev->name);
1540 
1541 	tunnel->hlen		= sizeof(struct ipv6hdr) + 4;
1542 }
1543 
1544 static struct inet6_protocol ip6gre_protocol __read_mostly = {
1545 	.handler     = gre_rcv,
1546 	.err_handler = ip6gre_err,
1547 	.flags       = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1548 };
1549 
1550 static void ip6gre_destroy_tunnels(struct net *net, struct list_head *head)
1551 {
1552 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1553 	struct net_device *dev, *aux;
1554 	int prio;
1555 
1556 	for_each_netdev_safe(net, dev, aux)
1557 		if (dev->rtnl_link_ops == &ip6gre_link_ops ||
1558 		    dev->rtnl_link_ops == &ip6gre_tap_ops ||
1559 		    dev->rtnl_link_ops == &ip6erspan_tap_ops)
1560 			unregister_netdevice_queue(dev, head);
1561 
1562 	for (prio = 0; prio < 4; prio++) {
1563 		int h;
1564 		for (h = 0; h < IP6_GRE_HASH_SIZE; h++) {
1565 			struct ip6_tnl *t;
1566 
1567 			t = rtnl_dereference(ign->tunnels[prio][h]);
1568 
1569 			while (t) {
1570 				/* If dev is in the same netns, it has already
1571 				 * been added to the list by the previous loop.
1572 				 */
1573 				if (!net_eq(dev_net(t->dev), net))
1574 					unregister_netdevice_queue(t->dev,
1575 								   head);
1576 				t = rtnl_dereference(t->next);
1577 			}
1578 		}
1579 	}
1580 }
1581 
1582 static int __net_init ip6gre_init_net(struct net *net)
1583 {
1584 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1585 	struct net_device *ndev;
1586 	int err;
1587 
1588 	if (!net_has_fallback_tunnels(net))
1589 		return 0;
1590 	ndev = alloc_netdev(sizeof(struct ip6_tnl), "ip6gre0",
1591 			    NET_NAME_UNKNOWN, ip6gre_tunnel_setup);
1592 	if (!ndev) {
1593 		err = -ENOMEM;
1594 		goto err_alloc_dev;
1595 	}
1596 	ign->fb_tunnel_dev = ndev;
1597 	dev_net_set(ign->fb_tunnel_dev, net);
1598 	/* FB netdevice is special: we have one, and only one per netns.
1599 	 * Allowing to move it to another netns is clearly unsafe.
1600 	 */
1601 	ign->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
1602 
1603 
1604 	ip6gre_fb_tunnel_init(ign->fb_tunnel_dev);
1605 	ign->fb_tunnel_dev->rtnl_link_ops = &ip6gre_link_ops;
1606 
1607 	err = register_netdev(ign->fb_tunnel_dev);
1608 	if (err)
1609 		goto err_reg_dev;
1610 
1611 	rcu_assign_pointer(ign->tunnels_wc[0],
1612 			   netdev_priv(ign->fb_tunnel_dev));
1613 	return 0;
1614 
1615 err_reg_dev:
1616 	free_netdev(ndev);
1617 err_alloc_dev:
1618 	return err;
1619 }
1620 
1621 static void __net_exit ip6gre_exit_batch_net(struct list_head *net_list)
1622 {
1623 	struct net *net;
1624 	LIST_HEAD(list);
1625 
1626 	rtnl_lock();
1627 	list_for_each_entry(net, net_list, exit_list)
1628 		ip6gre_destroy_tunnels(net, &list);
1629 	unregister_netdevice_many(&list);
1630 	rtnl_unlock();
1631 }
1632 
1633 static struct pernet_operations ip6gre_net_ops = {
1634 	.init = ip6gre_init_net,
1635 	.exit_batch = ip6gre_exit_batch_net,
1636 	.id   = &ip6gre_net_id,
1637 	.size = sizeof(struct ip6gre_net),
1638 };
1639 
1640 static int ip6gre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[],
1641 				  struct netlink_ext_ack *extack)
1642 {
1643 	__be16 flags;
1644 
1645 	if (!data)
1646 		return 0;
1647 
1648 	flags = 0;
1649 	if (data[IFLA_GRE_IFLAGS])
1650 		flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1651 	if (data[IFLA_GRE_OFLAGS])
1652 		flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1653 	if (flags & (GRE_VERSION|GRE_ROUTING))
1654 		return -EINVAL;
1655 
1656 	return 0;
1657 }
1658 
1659 static int ip6gre_tap_validate(struct nlattr *tb[], struct nlattr *data[],
1660 			       struct netlink_ext_ack *extack)
1661 {
1662 	struct in6_addr daddr;
1663 
1664 	if (tb[IFLA_ADDRESS]) {
1665 		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1666 			return -EINVAL;
1667 		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1668 			return -EADDRNOTAVAIL;
1669 	}
1670 
1671 	if (!data)
1672 		goto out;
1673 
1674 	if (data[IFLA_GRE_REMOTE]) {
1675 		daddr = nla_get_in6_addr(data[IFLA_GRE_REMOTE]);
1676 		if (ipv6_addr_any(&daddr))
1677 			return -EINVAL;
1678 	}
1679 
1680 out:
1681 	return ip6gre_tunnel_validate(tb, data, extack);
1682 }
1683 
1684 static int ip6erspan_tap_validate(struct nlattr *tb[], struct nlattr *data[],
1685 				  struct netlink_ext_ack *extack)
1686 {
1687 	__be16 flags = 0;
1688 	int ret, ver = 0;
1689 
1690 	if (!data)
1691 		return 0;
1692 
1693 	ret = ip6gre_tap_validate(tb, data, extack);
1694 	if (ret)
1695 		return ret;
1696 
1697 	/* ERSPAN should only have GRE sequence and key flag */
1698 	if (data[IFLA_GRE_OFLAGS])
1699 		flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1700 	if (data[IFLA_GRE_IFLAGS])
1701 		flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1702 	if (!data[IFLA_GRE_COLLECT_METADATA] &&
1703 	    flags != (GRE_SEQ | GRE_KEY))
1704 		return -EINVAL;
1705 
1706 	/* ERSPAN Session ID only has 10-bit. Since we reuse
1707 	 * 32-bit key field as ID, check it's range.
1708 	 */
1709 	if (data[IFLA_GRE_IKEY] &&
1710 	    (ntohl(nla_get_be32(data[IFLA_GRE_IKEY])) & ~ID_MASK))
1711 		return -EINVAL;
1712 
1713 	if (data[IFLA_GRE_OKEY] &&
1714 	    (ntohl(nla_get_be32(data[IFLA_GRE_OKEY])) & ~ID_MASK))
1715 		return -EINVAL;
1716 
1717 	if (data[IFLA_GRE_ERSPAN_VER]) {
1718 		ver = nla_get_u8(data[IFLA_GRE_ERSPAN_VER]);
1719 		if (ver != 1 && ver != 2)
1720 			return -EINVAL;
1721 	}
1722 
1723 	if (ver == 1) {
1724 		if (data[IFLA_GRE_ERSPAN_INDEX]) {
1725 			u32 index = nla_get_u32(data[IFLA_GRE_ERSPAN_INDEX]);
1726 
1727 			if (index & ~INDEX_MASK)
1728 				return -EINVAL;
1729 		}
1730 	} else if (ver == 2) {
1731 		if (data[IFLA_GRE_ERSPAN_DIR]) {
1732 			u16 dir = nla_get_u8(data[IFLA_GRE_ERSPAN_DIR]);
1733 
1734 			if (dir & ~(DIR_MASK >> DIR_OFFSET))
1735 				return -EINVAL;
1736 		}
1737 
1738 		if (data[IFLA_GRE_ERSPAN_HWID]) {
1739 			u16 hwid = nla_get_u16(data[IFLA_GRE_ERSPAN_HWID]);
1740 
1741 			if (hwid & ~(HWID_MASK >> HWID_OFFSET))
1742 				return -EINVAL;
1743 		}
1744 	}
1745 
1746 	return 0;
1747 }
1748 
1749 static void ip6erspan_set_version(struct nlattr *data[],
1750 				  struct __ip6_tnl_parm *parms)
1751 {
1752 	if (!data)
1753 		return;
1754 
1755 	parms->erspan_ver = 1;
1756 	if (data[IFLA_GRE_ERSPAN_VER])
1757 		parms->erspan_ver = nla_get_u8(data[IFLA_GRE_ERSPAN_VER]);
1758 
1759 	if (parms->erspan_ver == 1) {
1760 		if (data[IFLA_GRE_ERSPAN_INDEX])
1761 			parms->index = nla_get_u32(data[IFLA_GRE_ERSPAN_INDEX]);
1762 	} else if (parms->erspan_ver == 2) {
1763 		if (data[IFLA_GRE_ERSPAN_DIR])
1764 			parms->dir = nla_get_u8(data[IFLA_GRE_ERSPAN_DIR]);
1765 		if (data[IFLA_GRE_ERSPAN_HWID])
1766 			parms->hwid = nla_get_u16(data[IFLA_GRE_ERSPAN_HWID]);
1767 	}
1768 }
1769 
1770 static void ip6gre_netlink_parms(struct nlattr *data[],
1771 				struct __ip6_tnl_parm *parms)
1772 {
1773 	memset(parms, 0, sizeof(*parms));
1774 
1775 	if (!data)
1776 		return;
1777 
1778 	if (data[IFLA_GRE_LINK])
1779 		parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
1780 
1781 	if (data[IFLA_GRE_IFLAGS])
1782 		parms->i_flags = gre_flags_to_tnl_flags(
1783 				nla_get_be16(data[IFLA_GRE_IFLAGS]));
1784 
1785 	if (data[IFLA_GRE_OFLAGS])
1786 		parms->o_flags = gre_flags_to_tnl_flags(
1787 				nla_get_be16(data[IFLA_GRE_OFLAGS]));
1788 
1789 	if (data[IFLA_GRE_IKEY])
1790 		parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
1791 
1792 	if (data[IFLA_GRE_OKEY])
1793 		parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
1794 
1795 	if (data[IFLA_GRE_LOCAL])
1796 		parms->laddr = nla_get_in6_addr(data[IFLA_GRE_LOCAL]);
1797 
1798 	if (data[IFLA_GRE_REMOTE])
1799 		parms->raddr = nla_get_in6_addr(data[IFLA_GRE_REMOTE]);
1800 
1801 	if (data[IFLA_GRE_TTL])
1802 		parms->hop_limit = nla_get_u8(data[IFLA_GRE_TTL]);
1803 
1804 	if (data[IFLA_GRE_ENCAP_LIMIT])
1805 		parms->encap_limit = nla_get_u8(data[IFLA_GRE_ENCAP_LIMIT]);
1806 
1807 	if (data[IFLA_GRE_FLOWINFO])
1808 		parms->flowinfo = nla_get_be32(data[IFLA_GRE_FLOWINFO]);
1809 
1810 	if (data[IFLA_GRE_FLAGS])
1811 		parms->flags = nla_get_u32(data[IFLA_GRE_FLAGS]);
1812 
1813 	if (data[IFLA_GRE_FWMARK])
1814 		parms->fwmark = nla_get_u32(data[IFLA_GRE_FWMARK]);
1815 
1816 	if (data[IFLA_GRE_COLLECT_METADATA])
1817 		parms->collect_md = true;
1818 }
1819 
1820 static int ip6gre_tap_init(struct net_device *dev)
1821 {
1822 	int ret;
1823 
1824 	ret = ip6gre_tunnel_init_common(dev);
1825 	if (ret)
1826 		return ret;
1827 
1828 	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1829 
1830 	return 0;
1831 }
1832 
1833 static const struct net_device_ops ip6gre_tap_netdev_ops = {
1834 	.ndo_init = ip6gre_tap_init,
1835 	.ndo_uninit = ip6gre_tunnel_uninit,
1836 	.ndo_start_xmit = ip6gre_tunnel_xmit,
1837 	.ndo_set_mac_address = eth_mac_addr,
1838 	.ndo_validate_addr = eth_validate_addr,
1839 	.ndo_change_mtu = ip6_tnl_change_mtu,
1840 	.ndo_get_stats64 = dev_get_tstats64,
1841 	.ndo_get_iflink = ip6_tnl_get_iflink,
1842 };
1843 
1844 static int ip6erspan_calc_hlen(struct ip6_tnl *tunnel)
1845 {
1846 	int t_hlen;
1847 
1848 	tunnel->tun_hlen = 8;
1849 	tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen +
1850 		       erspan_hdr_len(tunnel->parms.erspan_ver);
1851 
1852 	t_hlen = tunnel->hlen + sizeof(struct ipv6hdr);
1853 	tunnel->dev->needed_headroom = LL_MAX_HEADER + t_hlen;
1854 	return t_hlen;
1855 }
1856 
1857 static int ip6erspan_tap_init(struct net_device *dev)
1858 {
1859 	struct ip6_tnl *tunnel;
1860 	int t_hlen;
1861 	int ret;
1862 
1863 	tunnel = netdev_priv(dev);
1864 
1865 	tunnel->dev = dev;
1866 	tunnel->net = dev_net(dev);
1867 	strcpy(tunnel->parms.name, dev->name);
1868 
1869 	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1870 	if (!dev->tstats)
1871 		return -ENOMEM;
1872 
1873 	ret = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL);
1874 	if (ret)
1875 		goto cleanup_alloc_pcpu_stats;
1876 
1877 	ret = gro_cells_init(&tunnel->gro_cells, dev);
1878 	if (ret)
1879 		goto cleanup_dst_cache_init;
1880 
1881 	t_hlen = ip6erspan_calc_hlen(tunnel);
1882 	dev->mtu = ETH_DATA_LEN - t_hlen;
1883 	if (dev->type == ARPHRD_ETHER)
1884 		dev->mtu -= ETH_HLEN;
1885 	if (!(tunnel->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1886 		dev->mtu -= 8;
1887 
1888 	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1889 	ip6erspan_tnl_link_config(tunnel, 1);
1890 
1891 	dev_hold_track(dev, &tunnel->dev_tracker, GFP_KERNEL);
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 out:
1992 	return err;
1993 }
1994 
1995 static int ip6gre_newlink(struct net *src_net, struct net_device *dev,
1996 			  struct nlattr *tb[], struct nlattr *data[],
1997 			  struct netlink_ext_ack *extack)
1998 {
1999 	struct ip6_tnl *nt = netdev_priv(dev);
2000 	struct net *net = dev_net(dev);
2001 	struct ip6gre_net *ign;
2002 	int err;
2003 
2004 	ip6gre_netlink_parms(data, &nt->parms);
2005 	ign = net_generic(net, ip6gre_net_id);
2006 
2007 	if (nt->parms.collect_md) {
2008 		if (rtnl_dereference(ign->collect_md_tun))
2009 			return -EEXIST;
2010 	} else {
2011 		if (ip6gre_tunnel_find(net, &nt->parms, dev->type))
2012 			return -EEXIST;
2013 	}
2014 
2015 	err = ip6gre_newlink_common(src_net, dev, tb, data, extack);
2016 	if (!err) {
2017 		ip6gre_tnl_link_config(nt, !tb[IFLA_MTU]);
2018 		ip6gre_tunnel_link_md(ign, nt);
2019 		ip6gre_tunnel_link(net_generic(net, ip6gre_net_id), nt);
2020 	}
2021 	return err;
2022 }
2023 
2024 static struct ip6_tnl *
2025 ip6gre_changelink_common(struct net_device *dev, struct nlattr *tb[],
2026 			 struct nlattr *data[], struct __ip6_tnl_parm *p_p,
2027 			 struct netlink_ext_ack *extack)
2028 {
2029 	struct ip6_tnl *t, *nt = netdev_priv(dev);
2030 	struct net *net = nt->net;
2031 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
2032 	struct ip_tunnel_encap ipencap;
2033 
2034 	if (dev == ign->fb_tunnel_dev)
2035 		return ERR_PTR(-EINVAL);
2036 
2037 	if (ip6gre_netlink_encap_parms(data, &ipencap)) {
2038 		int err = ip6_tnl_encap_setup(nt, &ipencap);
2039 
2040 		if (err < 0)
2041 			return ERR_PTR(err);
2042 	}
2043 
2044 	ip6gre_netlink_parms(data, p_p);
2045 
2046 	t = ip6gre_tunnel_locate(net, p_p, 0);
2047 
2048 	if (t) {
2049 		if (t->dev != dev)
2050 			return ERR_PTR(-EEXIST);
2051 	} else {
2052 		t = nt;
2053 	}
2054 
2055 	return t;
2056 }
2057 
2058 static int ip6gre_changelink(struct net_device *dev, struct nlattr *tb[],
2059 			     struct nlattr *data[],
2060 			     struct netlink_ext_ack *extack)
2061 {
2062 	struct ip6_tnl *t = netdev_priv(dev);
2063 	struct ip6gre_net *ign = net_generic(t->net, ip6gre_net_id);
2064 	struct __ip6_tnl_parm p;
2065 
2066 	t = ip6gre_changelink_common(dev, tb, data, &p, extack);
2067 	if (IS_ERR(t))
2068 		return PTR_ERR(t);
2069 
2070 	ip6gre_tunnel_unlink_md(ign, t);
2071 	ip6gre_tunnel_unlink(ign, t);
2072 	ip6gre_tnl_change(t, &p, !tb[IFLA_MTU]);
2073 	ip6gre_tunnel_link_md(ign, t);
2074 	ip6gre_tunnel_link(ign, t);
2075 	return 0;
2076 }
2077 
2078 static void ip6gre_dellink(struct net_device *dev, struct list_head *head)
2079 {
2080 	struct net *net = dev_net(dev);
2081 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
2082 
2083 	if (dev != ign->fb_tunnel_dev)
2084 		unregister_netdevice_queue(dev, head);
2085 }
2086 
2087 static size_t ip6gre_get_size(const struct net_device *dev)
2088 {
2089 	return
2090 		/* IFLA_GRE_LINK */
2091 		nla_total_size(4) +
2092 		/* IFLA_GRE_IFLAGS */
2093 		nla_total_size(2) +
2094 		/* IFLA_GRE_OFLAGS */
2095 		nla_total_size(2) +
2096 		/* IFLA_GRE_IKEY */
2097 		nla_total_size(4) +
2098 		/* IFLA_GRE_OKEY */
2099 		nla_total_size(4) +
2100 		/* IFLA_GRE_LOCAL */
2101 		nla_total_size(sizeof(struct in6_addr)) +
2102 		/* IFLA_GRE_REMOTE */
2103 		nla_total_size(sizeof(struct in6_addr)) +
2104 		/* IFLA_GRE_TTL */
2105 		nla_total_size(1) +
2106 		/* IFLA_GRE_ENCAP_LIMIT */
2107 		nla_total_size(1) +
2108 		/* IFLA_GRE_FLOWINFO */
2109 		nla_total_size(4) +
2110 		/* IFLA_GRE_FLAGS */
2111 		nla_total_size(4) +
2112 		/* IFLA_GRE_ENCAP_TYPE */
2113 		nla_total_size(2) +
2114 		/* IFLA_GRE_ENCAP_FLAGS */
2115 		nla_total_size(2) +
2116 		/* IFLA_GRE_ENCAP_SPORT */
2117 		nla_total_size(2) +
2118 		/* IFLA_GRE_ENCAP_DPORT */
2119 		nla_total_size(2) +
2120 		/* IFLA_GRE_COLLECT_METADATA */
2121 		nla_total_size(0) +
2122 		/* IFLA_GRE_FWMARK */
2123 		nla_total_size(4) +
2124 		/* IFLA_GRE_ERSPAN_INDEX */
2125 		nla_total_size(4) +
2126 		0;
2127 }
2128 
2129 static int ip6gre_fill_info(struct sk_buff *skb, const struct net_device *dev)
2130 {
2131 	struct ip6_tnl *t = netdev_priv(dev);
2132 	struct __ip6_tnl_parm *p = &t->parms;
2133 	__be16 o_flags = p->o_flags;
2134 
2135 	if (p->erspan_ver == 1 || p->erspan_ver == 2) {
2136 		if (!p->collect_md)
2137 			o_flags |= TUNNEL_KEY;
2138 
2139 		if (nla_put_u8(skb, IFLA_GRE_ERSPAN_VER, p->erspan_ver))
2140 			goto nla_put_failure;
2141 
2142 		if (p->erspan_ver == 1) {
2143 			if (nla_put_u32(skb, IFLA_GRE_ERSPAN_INDEX, p->index))
2144 				goto nla_put_failure;
2145 		} else {
2146 			if (nla_put_u8(skb, IFLA_GRE_ERSPAN_DIR, p->dir))
2147 				goto nla_put_failure;
2148 			if (nla_put_u16(skb, IFLA_GRE_ERSPAN_HWID, p->hwid))
2149 				goto nla_put_failure;
2150 		}
2151 	}
2152 
2153 	if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
2154 	    nla_put_be16(skb, IFLA_GRE_IFLAGS,
2155 			 gre_tnl_flags_to_gre_flags(p->i_flags)) ||
2156 	    nla_put_be16(skb, IFLA_GRE_OFLAGS,
2157 			 gre_tnl_flags_to_gre_flags(o_flags)) ||
2158 	    nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
2159 	    nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
2160 	    nla_put_in6_addr(skb, IFLA_GRE_LOCAL, &p->laddr) ||
2161 	    nla_put_in6_addr(skb, IFLA_GRE_REMOTE, &p->raddr) ||
2162 	    nla_put_u8(skb, IFLA_GRE_TTL, p->hop_limit) ||
2163 	    nla_put_u8(skb, IFLA_GRE_ENCAP_LIMIT, p->encap_limit) ||
2164 	    nla_put_be32(skb, IFLA_GRE_FLOWINFO, p->flowinfo) ||
2165 	    nla_put_u32(skb, IFLA_GRE_FLAGS, p->flags) ||
2166 	    nla_put_u32(skb, IFLA_GRE_FWMARK, p->fwmark))
2167 		goto nla_put_failure;
2168 
2169 	if (nla_put_u16(skb, IFLA_GRE_ENCAP_TYPE,
2170 			t->encap.type) ||
2171 	    nla_put_be16(skb, IFLA_GRE_ENCAP_SPORT,
2172 			 t->encap.sport) ||
2173 	    nla_put_be16(skb, IFLA_GRE_ENCAP_DPORT,
2174 			 t->encap.dport) ||
2175 	    nla_put_u16(skb, IFLA_GRE_ENCAP_FLAGS,
2176 			t->encap.flags))
2177 		goto nla_put_failure;
2178 
2179 	if (p->collect_md) {
2180 		if (nla_put_flag(skb, IFLA_GRE_COLLECT_METADATA))
2181 			goto nla_put_failure;
2182 	}
2183 
2184 	return 0;
2185 
2186 nla_put_failure:
2187 	return -EMSGSIZE;
2188 }
2189 
2190 static const struct nla_policy ip6gre_policy[IFLA_GRE_MAX + 1] = {
2191 	[IFLA_GRE_LINK]        = { .type = NLA_U32 },
2192 	[IFLA_GRE_IFLAGS]      = { .type = NLA_U16 },
2193 	[IFLA_GRE_OFLAGS]      = { .type = NLA_U16 },
2194 	[IFLA_GRE_IKEY]        = { .type = NLA_U32 },
2195 	[IFLA_GRE_OKEY]        = { .type = NLA_U32 },
2196 	[IFLA_GRE_LOCAL]       = { .len = sizeof_field(struct ipv6hdr, saddr) },
2197 	[IFLA_GRE_REMOTE]      = { .len = sizeof_field(struct ipv6hdr, daddr) },
2198 	[IFLA_GRE_TTL]         = { .type = NLA_U8 },
2199 	[IFLA_GRE_ENCAP_LIMIT] = { .type = NLA_U8 },
2200 	[IFLA_GRE_FLOWINFO]    = { .type = NLA_U32 },
2201 	[IFLA_GRE_FLAGS]       = { .type = NLA_U32 },
2202 	[IFLA_GRE_ENCAP_TYPE]   = { .type = NLA_U16 },
2203 	[IFLA_GRE_ENCAP_FLAGS]  = { .type = NLA_U16 },
2204 	[IFLA_GRE_ENCAP_SPORT]  = { .type = NLA_U16 },
2205 	[IFLA_GRE_ENCAP_DPORT]  = { .type = NLA_U16 },
2206 	[IFLA_GRE_COLLECT_METADATA] = { .type = NLA_FLAG },
2207 	[IFLA_GRE_FWMARK]       = { .type = NLA_U32 },
2208 	[IFLA_GRE_ERSPAN_INDEX] = { .type = NLA_U32 },
2209 	[IFLA_GRE_ERSPAN_VER]	= { .type = NLA_U8 },
2210 	[IFLA_GRE_ERSPAN_DIR]	= { .type = NLA_U8 },
2211 	[IFLA_GRE_ERSPAN_HWID]	= { .type = NLA_U16 },
2212 };
2213 
2214 static void ip6erspan_tap_setup(struct net_device *dev)
2215 {
2216 	ether_setup(dev);
2217 
2218 	dev->max_mtu = 0;
2219 	dev->netdev_ops = &ip6erspan_netdev_ops;
2220 	dev->needs_free_netdev = true;
2221 	dev->priv_destructor = ip6gre_dev_free;
2222 
2223 	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
2224 	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
2225 	netif_keep_dst(dev);
2226 }
2227 
2228 static int ip6erspan_newlink(struct net *src_net, struct net_device *dev,
2229 			     struct nlattr *tb[], struct nlattr *data[],
2230 			     struct netlink_ext_ack *extack)
2231 {
2232 	struct ip6_tnl *nt = netdev_priv(dev);
2233 	struct net *net = dev_net(dev);
2234 	struct ip6gre_net *ign;
2235 	int err;
2236 
2237 	ip6gre_netlink_parms(data, &nt->parms);
2238 	ip6erspan_set_version(data, &nt->parms);
2239 	ign = net_generic(net, ip6gre_net_id);
2240 
2241 	if (nt->parms.collect_md) {
2242 		if (rtnl_dereference(ign->collect_md_tun_erspan))
2243 			return -EEXIST;
2244 	} else {
2245 		if (ip6gre_tunnel_find(net, &nt->parms, dev->type))
2246 			return -EEXIST;
2247 	}
2248 
2249 	err = ip6gre_newlink_common(src_net, dev, tb, data, extack);
2250 	if (!err) {
2251 		ip6erspan_tnl_link_config(nt, !tb[IFLA_MTU]);
2252 		ip6erspan_tunnel_link_md(ign, nt);
2253 		ip6gre_tunnel_link(net_generic(net, ip6gre_net_id), nt);
2254 	}
2255 	return err;
2256 }
2257 
2258 static void ip6erspan_tnl_link_config(struct ip6_tnl *t, int set_mtu)
2259 {
2260 	ip6gre_tnl_link_config_common(t);
2261 	ip6gre_tnl_link_config_route(t, set_mtu, ip6erspan_calc_hlen(t));
2262 }
2263 
2264 static int ip6erspan_tnl_change(struct ip6_tnl *t,
2265 				const struct __ip6_tnl_parm *p, int set_mtu)
2266 {
2267 	ip6gre_tnl_copy_tnl_parm(t, p);
2268 	ip6erspan_tnl_link_config(t, set_mtu);
2269 	return 0;
2270 }
2271 
2272 static int ip6erspan_changelink(struct net_device *dev, struct nlattr *tb[],
2273 				struct nlattr *data[],
2274 				struct netlink_ext_ack *extack)
2275 {
2276 	struct ip6gre_net *ign = net_generic(dev_net(dev), ip6gre_net_id);
2277 	struct __ip6_tnl_parm p;
2278 	struct ip6_tnl *t;
2279 
2280 	t = ip6gre_changelink_common(dev, tb, data, &p, extack);
2281 	if (IS_ERR(t))
2282 		return PTR_ERR(t);
2283 
2284 	ip6erspan_set_version(data, &p);
2285 	ip6gre_tunnel_unlink_md(ign, t);
2286 	ip6gre_tunnel_unlink(ign, t);
2287 	ip6erspan_tnl_change(t, &p, !tb[IFLA_MTU]);
2288 	ip6erspan_tunnel_link_md(ign, t);
2289 	ip6gre_tunnel_link(ign, t);
2290 	return 0;
2291 }
2292 
2293 static struct rtnl_link_ops ip6gre_link_ops __read_mostly = {
2294 	.kind		= "ip6gre",
2295 	.maxtype	= IFLA_GRE_MAX,
2296 	.policy		= ip6gre_policy,
2297 	.priv_size	= sizeof(struct ip6_tnl),
2298 	.setup		= ip6gre_tunnel_setup,
2299 	.validate	= ip6gre_tunnel_validate,
2300 	.newlink	= ip6gre_newlink,
2301 	.changelink	= ip6gre_changelink,
2302 	.dellink	= ip6gre_dellink,
2303 	.get_size	= ip6gre_get_size,
2304 	.fill_info	= ip6gre_fill_info,
2305 	.get_link_net	= ip6_tnl_get_link_net,
2306 };
2307 
2308 static struct rtnl_link_ops ip6gre_tap_ops __read_mostly = {
2309 	.kind		= "ip6gretap",
2310 	.maxtype	= IFLA_GRE_MAX,
2311 	.policy		= ip6gre_policy,
2312 	.priv_size	= sizeof(struct ip6_tnl),
2313 	.setup		= ip6gre_tap_setup,
2314 	.validate	= ip6gre_tap_validate,
2315 	.newlink	= ip6gre_newlink,
2316 	.changelink	= ip6gre_changelink,
2317 	.get_size	= ip6gre_get_size,
2318 	.fill_info	= ip6gre_fill_info,
2319 	.get_link_net	= ip6_tnl_get_link_net,
2320 };
2321 
2322 static struct rtnl_link_ops ip6erspan_tap_ops __read_mostly = {
2323 	.kind		= "ip6erspan",
2324 	.maxtype	= IFLA_GRE_MAX,
2325 	.policy		= ip6gre_policy,
2326 	.priv_size	= sizeof(struct ip6_tnl),
2327 	.setup		= ip6erspan_tap_setup,
2328 	.validate	= ip6erspan_tap_validate,
2329 	.newlink	= ip6erspan_newlink,
2330 	.changelink	= ip6erspan_changelink,
2331 	.get_size	= ip6gre_get_size,
2332 	.fill_info	= ip6gre_fill_info,
2333 	.get_link_net	= ip6_tnl_get_link_net,
2334 };
2335 
2336 /*
2337  *	And now the modules code and kernel interface.
2338  */
2339 
2340 static int __init ip6gre_init(void)
2341 {
2342 	int err;
2343 
2344 	pr_info("GRE over IPv6 tunneling driver\n");
2345 
2346 	err = register_pernet_device(&ip6gre_net_ops);
2347 	if (err < 0)
2348 		return err;
2349 
2350 	err = inet6_add_protocol(&ip6gre_protocol, IPPROTO_GRE);
2351 	if (err < 0) {
2352 		pr_info("%s: can't add protocol\n", __func__);
2353 		goto add_proto_failed;
2354 	}
2355 
2356 	err = rtnl_link_register(&ip6gre_link_ops);
2357 	if (err < 0)
2358 		goto rtnl_link_failed;
2359 
2360 	err = rtnl_link_register(&ip6gre_tap_ops);
2361 	if (err < 0)
2362 		goto tap_ops_failed;
2363 
2364 	err = rtnl_link_register(&ip6erspan_tap_ops);
2365 	if (err < 0)
2366 		goto erspan_link_failed;
2367 
2368 out:
2369 	return err;
2370 
2371 erspan_link_failed:
2372 	rtnl_link_unregister(&ip6gre_tap_ops);
2373 tap_ops_failed:
2374 	rtnl_link_unregister(&ip6gre_link_ops);
2375 rtnl_link_failed:
2376 	inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
2377 add_proto_failed:
2378 	unregister_pernet_device(&ip6gre_net_ops);
2379 	goto out;
2380 }
2381 
2382 static void __exit ip6gre_fini(void)
2383 {
2384 	rtnl_link_unregister(&ip6gre_tap_ops);
2385 	rtnl_link_unregister(&ip6gre_link_ops);
2386 	rtnl_link_unregister(&ip6erspan_tap_ops);
2387 	inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
2388 	unregister_pernet_device(&ip6gre_net_ops);
2389 }
2390 
2391 module_init(ip6gre_init);
2392 module_exit(ip6gre_fini);
2393 MODULE_LICENSE("GPL");
2394 MODULE_AUTHOR("D. Kozlov (xeb@mail.ru)");
2395 MODULE_DESCRIPTION("GRE over IPv6 tunneling device");
2396 MODULE_ALIAS_RTNL_LINK("ip6gre");
2397 MODULE_ALIAS_RTNL_LINK("ip6gretap");
2398 MODULE_ALIAS_RTNL_LINK("ip6erspan");
2399 MODULE_ALIAS_NETDEV("ip6gre0");
2400