xref: /openbmc/linux/net/ipv6/ip6_gre.c (revision 464a5728)
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(dev);
407 }
408 
409 static void ip6gre_tunnel_uninit(struct net_device *dev)
410 {
411 	struct ip6_tnl *t = netdev_priv(dev);
412 	struct ip6gre_net *ign = net_generic(t->net, ip6gre_net_id);
413 
414 	ip6gre_tunnel_unlink_md(ign, t);
415 	ip6gre_tunnel_unlink(ign, t);
416 	if (ign->fb_tunnel_dev == dev)
417 		WRITE_ONCE(ign->fb_tunnel_dev, NULL);
418 	dst_cache_reset(&t->dst_cache);
419 	dev_put(dev);
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 	if (csum && skb_checksum_start(skb) < skb->data)
633 		return -EINVAL;
634 	return iptunnel_handle_offloads(skb,
635 					csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE);
636 }
637 
638 static void prepare_ip6gre_xmit_ipv4(struct sk_buff *skb,
639 				     struct net_device *dev,
640 				     struct flowi6 *fl6, __u8 *dsfield,
641 				     int *encap_limit)
642 {
643 	const struct iphdr *iph = ip_hdr(skb);
644 	struct ip6_tnl *t = netdev_priv(dev);
645 
646 	if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
647 		*encap_limit = t->parms.encap_limit;
648 
649 	memcpy(fl6, &t->fl.u.ip6, sizeof(*fl6));
650 
651 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
652 		*dsfield = ipv4_get_dsfield(iph);
653 	else
654 		*dsfield = ip6_tclass(t->parms.flowinfo);
655 
656 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
657 		fl6->flowi6_mark = skb->mark;
658 	else
659 		fl6->flowi6_mark = t->parms.fwmark;
660 
661 	fl6->flowi6_uid = sock_net_uid(dev_net(dev), NULL);
662 }
663 
664 static int prepare_ip6gre_xmit_ipv6(struct sk_buff *skb,
665 				    struct net_device *dev,
666 				    struct flowi6 *fl6, __u8 *dsfield,
667 				    int *encap_limit)
668 {
669 	struct ipv6hdr *ipv6h;
670 	struct ip6_tnl *t = netdev_priv(dev);
671 	__u16 offset;
672 
673 	offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
674 	/* ip6_tnl_parse_tlv_enc_lim() might have reallocated skb->head */
675 	ipv6h = ipv6_hdr(skb);
676 
677 	if (offset > 0) {
678 		struct ipv6_tlv_tnl_enc_lim *tel;
679 
680 		tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset];
681 		if (tel->encap_limit == 0) {
682 			icmpv6_ndo_send(skb, ICMPV6_PARAMPROB,
683 					ICMPV6_HDR_FIELD, offset + 2);
684 			return -1;
685 		}
686 		*encap_limit = tel->encap_limit - 1;
687 	} else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) {
688 		*encap_limit = t->parms.encap_limit;
689 	}
690 
691 	memcpy(fl6, &t->fl.u.ip6, sizeof(*fl6));
692 
693 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
694 		*dsfield = ipv6_get_dsfield(ipv6h);
695 	else
696 		*dsfield = ip6_tclass(t->parms.flowinfo);
697 
698 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
699 		fl6->flowlabel |= ip6_flowlabel(ipv6h);
700 
701 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
702 		fl6->flowi6_mark = skb->mark;
703 	else
704 		fl6->flowi6_mark = t->parms.fwmark;
705 
706 	fl6->flowi6_uid = sock_net_uid(dev_net(dev), NULL);
707 
708 	return 0;
709 }
710 
711 static struct ip_tunnel_info *skb_tunnel_info_txcheck(struct sk_buff *skb)
712 {
713 	struct ip_tunnel_info *tun_info;
714 
715 	tun_info = skb_tunnel_info(skb);
716 	if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX)))
717 		return ERR_PTR(-EINVAL);
718 
719 	return tun_info;
720 }
721 
722 static netdev_tx_t __gre6_xmit(struct sk_buff *skb,
723 			       struct net_device *dev, __u8 dsfield,
724 			       struct flowi6 *fl6, int encap_limit,
725 			       __u32 *pmtu, __be16 proto)
726 {
727 	struct ip6_tnl *tunnel = netdev_priv(dev);
728 	__be16 protocol;
729 
730 	if (dev->type == ARPHRD_ETHER)
731 		IPCB(skb)->flags = 0;
732 
733 	if (dev->header_ops && dev->type == ARPHRD_IP6GRE)
734 		fl6->daddr = ((struct ipv6hdr *)skb->data)->daddr;
735 	else
736 		fl6->daddr = tunnel->parms.raddr;
737 
738 	if (skb_cow_head(skb, dev->needed_headroom ?: tunnel->hlen))
739 		return -ENOMEM;
740 
741 	/* Push GRE header. */
742 	protocol = (dev->type == ARPHRD_ETHER) ? htons(ETH_P_TEB) : proto;
743 
744 	if (tunnel->parms.collect_md) {
745 		struct ip_tunnel_info *tun_info;
746 		const struct ip_tunnel_key *key;
747 		__be16 flags;
748 
749 		tun_info = skb_tunnel_info_txcheck(skb);
750 		if (IS_ERR(tun_info) ||
751 		    unlikely(ip_tunnel_info_af(tun_info) != AF_INET6))
752 			return -EINVAL;
753 
754 		key = &tun_info->key;
755 		memset(fl6, 0, sizeof(*fl6));
756 		fl6->flowi6_proto = IPPROTO_GRE;
757 		fl6->daddr = key->u.ipv6.dst;
758 		fl6->flowlabel = key->label;
759 		fl6->flowi6_uid = sock_net_uid(dev_net(dev), NULL);
760 
761 		dsfield = key->tos;
762 		flags = key->tun_flags &
763 			(TUNNEL_CSUM | TUNNEL_KEY | TUNNEL_SEQ);
764 		tunnel->tun_hlen = gre_calc_hlen(flags);
765 
766 		gre_build_header(skb, tunnel->tun_hlen,
767 				 flags, protocol,
768 				 tunnel_id_to_key32(tun_info->key.tun_id),
769 				 (flags & TUNNEL_SEQ) ? htonl(tunnel->o_seqno++)
770 						      : 0);
771 
772 	} else {
773 		if (tunnel->parms.o_flags & TUNNEL_SEQ)
774 			tunnel->o_seqno++;
775 
776 		gre_build_header(skb, tunnel->tun_hlen, tunnel->parms.o_flags,
777 				 protocol, tunnel->parms.o_key,
778 				 htonl(tunnel->o_seqno));
779 	}
780 
781 	return ip6_tnl_xmit(skb, dev, dsfield, fl6, encap_limit, pmtu,
782 			    NEXTHDR_GRE);
783 }
784 
785 static inline int ip6gre_xmit_ipv4(struct sk_buff *skb, struct net_device *dev)
786 {
787 	struct ip6_tnl *t = netdev_priv(dev);
788 	int encap_limit = -1;
789 	struct flowi6 fl6;
790 	__u8 dsfield = 0;
791 	__u32 mtu;
792 	int err;
793 
794 	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
795 
796 	if (!t->parms.collect_md)
797 		prepare_ip6gre_xmit_ipv4(skb, dev, &fl6,
798 					 &dsfield, &encap_limit);
799 
800 	err = gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM));
801 	if (err)
802 		return -1;
803 
804 	err = __gre6_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
805 			  skb->protocol);
806 	if (err != 0) {
807 		/* XXX: send ICMP error even if DF is not set. */
808 		if (err == -EMSGSIZE)
809 			icmp_ndo_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
810 				      htonl(mtu));
811 		return -1;
812 	}
813 
814 	return 0;
815 }
816 
817 static inline int ip6gre_xmit_ipv6(struct sk_buff *skb, struct net_device *dev)
818 {
819 	struct ip6_tnl *t = netdev_priv(dev);
820 	struct ipv6hdr *ipv6h = ipv6_hdr(skb);
821 	int encap_limit = -1;
822 	struct flowi6 fl6;
823 	__u8 dsfield = 0;
824 	__u32 mtu;
825 	int err;
826 
827 	if (ipv6_addr_equal(&t->parms.raddr, &ipv6h->saddr))
828 		return -1;
829 
830 	if (!t->parms.collect_md &&
831 	    prepare_ip6gre_xmit_ipv6(skb, dev, &fl6, &dsfield, &encap_limit))
832 		return -1;
833 
834 	if (gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM)))
835 		return -1;
836 
837 	err = __gre6_xmit(skb, dev, dsfield, &fl6, encap_limit,
838 			  &mtu, skb->protocol);
839 	if (err != 0) {
840 		if (err == -EMSGSIZE)
841 			icmpv6_ndo_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
842 		return -1;
843 	}
844 
845 	return 0;
846 }
847 
848 /**
849  * ip6gre_tnl_addr_conflict - compare packet addresses to tunnel's own
850  *   @t: the outgoing tunnel device
851  *   @hdr: IPv6 header from the incoming packet
852  *
853  * Description:
854  *   Avoid trivial tunneling loop by checking that tunnel exit-point
855  *   doesn't match source of incoming packet.
856  *
857  * Return:
858  *   1 if conflict,
859  *   0 else
860  **/
861 
862 static inline bool ip6gre_tnl_addr_conflict(const struct ip6_tnl *t,
863 	const struct ipv6hdr *hdr)
864 {
865 	return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
866 }
867 
868 static int ip6gre_xmit_other(struct sk_buff *skb, struct net_device *dev)
869 {
870 	struct ip6_tnl *t = netdev_priv(dev);
871 	int encap_limit = -1;
872 	struct flowi6 fl6;
873 	__u32 mtu;
874 	int err;
875 
876 	if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
877 		encap_limit = t->parms.encap_limit;
878 
879 	if (!t->parms.collect_md)
880 		memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
881 
882 	err = gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM));
883 	if (err)
884 		return err;
885 
886 	err = __gre6_xmit(skb, dev, 0, &fl6, encap_limit, &mtu, skb->protocol);
887 
888 	return err;
889 }
890 
891 static netdev_tx_t ip6gre_tunnel_xmit(struct sk_buff *skb,
892 	struct net_device *dev)
893 {
894 	struct ip6_tnl *t = netdev_priv(dev);
895 	struct net_device_stats *stats = &t->dev->stats;
896 	int ret;
897 
898 	if (!pskb_inet_may_pull(skb))
899 		goto tx_err;
900 
901 	if (!ip6_tnl_xmit_ctl(t, &t->parms.laddr, &t->parms.raddr))
902 		goto tx_err;
903 
904 	switch (skb->protocol) {
905 	case htons(ETH_P_IP):
906 		ret = ip6gre_xmit_ipv4(skb, dev);
907 		break;
908 	case htons(ETH_P_IPV6):
909 		ret = ip6gre_xmit_ipv6(skb, dev);
910 		break;
911 	default:
912 		ret = ip6gre_xmit_other(skb, dev);
913 		break;
914 	}
915 
916 	if (ret < 0)
917 		goto tx_err;
918 
919 	return NETDEV_TX_OK;
920 
921 tx_err:
922 	if (!t->parms.collect_md || !IS_ERR(skb_tunnel_info_txcheck(skb)))
923 		stats->tx_errors++;
924 	stats->tx_dropped++;
925 	kfree_skb(skb);
926 	return NETDEV_TX_OK;
927 }
928 
929 static netdev_tx_t ip6erspan_tunnel_xmit(struct sk_buff *skb,
930 					 struct net_device *dev)
931 {
932 	struct ip_tunnel_info *tun_info = NULL;
933 	struct ip6_tnl *t = netdev_priv(dev);
934 	struct dst_entry *dst = skb_dst(skb);
935 	struct net_device_stats *stats;
936 	bool truncate = false;
937 	int encap_limit = -1;
938 	__u8 dsfield = false;
939 	struct flowi6 fl6;
940 	int err = -EINVAL;
941 	__be16 proto;
942 	__u32 mtu;
943 	int nhoff;
944 	int thoff;
945 
946 	if (!pskb_inet_may_pull(skb))
947 		goto tx_err;
948 
949 	if (!ip6_tnl_xmit_ctl(t, &t->parms.laddr, &t->parms.raddr))
950 		goto tx_err;
951 
952 	if (gre_handle_offloads(skb, false))
953 		goto tx_err;
954 
955 	if (skb->len > dev->mtu + dev->hard_header_len) {
956 		pskb_trim(skb, dev->mtu + dev->hard_header_len);
957 		truncate = true;
958 	}
959 
960 	nhoff = skb_network_header(skb) - skb_mac_header(skb);
961 	if (skb->protocol == htons(ETH_P_IP) &&
962 	    (ntohs(ip_hdr(skb)->tot_len) > skb->len - nhoff))
963 		truncate = true;
964 
965 	thoff = skb_transport_header(skb) - skb_mac_header(skb);
966 	if (skb->protocol == htons(ETH_P_IPV6) &&
967 	    (ntohs(ipv6_hdr(skb)->payload_len) > skb->len - thoff))
968 		truncate = true;
969 
970 	if (skb_cow_head(skb, dev->needed_headroom ?: t->hlen))
971 		goto tx_err;
972 
973 	t->parms.o_flags &= ~TUNNEL_KEY;
974 	IPCB(skb)->flags = 0;
975 
976 	/* For collect_md mode, derive fl6 from the tunnel key,
977 	 * for native mode, call prepare_ip6gre_xmit_{ipv4,ipv6}.
978 	 */
979 	if (t->parms.collect_md) {
980 		const struct ip_tunnel_key *key;
981 		struct erspan_metadata *md;
982 		__be32 tun_id;
983 
984 		tun_info = skb_tunnel_info_txcheck(skb);
985 		if (IS_ERR(tun_info) ||
986 		    unlikely(ip_tunnel_info_af(tun_info) != AF_INET6))
987 			goto tx_err;
988 
989 		key = &tun_info->key;
990 		memset(&fl6, 0, sizeof(fl6));
991 		fl6.flowi6_proto = IPPROTO_GRE;
992 		fl6.daddr = key->u.ipv6.dst;
993 		fl6.flowlabel = key->label;
994 		fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
995 
996 		dsfield = key->tos;
997 		if (!(tun_info->key.tun_flags & TUNNEL_ERSPAN_OPT))
998 			goto tx_err;
999 		if (tun_info->options_len < sizeof(*md))
1000 			goto tx_err;
1001 		md = ip_tunnel_info_opts(tun_info);
1002 
1003 		tun_id = tunnel_id_to_key32(key->tun_id);
1004 		if (md->version == 1) {
1005 			erspan_build_header(skb,
1006 					    ntohl(tun_id),
1007 					    ntohl(md->u.index), truncate,
1008 					    false);
1009 		} else if (md->version == 2) {
1010 			erspan_build_header_v2(skb,
1011 					       ntohl(tun_id),
1012 					       md->u.md2.dir,
1013 					       get_hwid(&md->u.md2),
1014 					       truncate, false);
1015 		} else {
1016 			goto tx_err;
1017 		}
1018 	} else {
1019 		switch (skb->protocol) {
1020 		case htons(ETH_P_IP):
1021 			memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1022 			prepare_ip6gre_xmit_ipv4(skb, dev, &fl6,
1023 						 &dsfield, &encap_limit);
1024 			break;
1025 		case htons(ETH_P_IPV6):
1026 			if (ipv6_addr_equal(&t->parms.raddr, &ipv6_hdr(skb)->saddr))
1027 				goto tx_err;
1028 			if (prepare_ip6gre_xmit_ipv6(skb, dev, &fl6,
1029 						     &dsfield, &encap_limit))
1030 				goto tx_err;
1031 			break;
1032 		default:
1033 			memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
1034 			break;
1035 		}
1036 
1037 		if (t->parms.erspan_ver == 1)
1038 			erspan_build_header(skb, ntohl(t->parms.o_key),
1039 					    t->parms.index,
1040 					    truncate, false);
1041 		else if (t->parms.erspan_ver == 2)
1042 			erspan_build_header_v2(skb, ntohl(t->parms.o_key),
1043 					       t->parms.dir,
1044 					       t->parms.hwid,
1045 					       truncate, false);
1046 		else
1047 			goto tx_err;
1048 
1049 		fl6.daddr = t->parms.raddr;
1050 	}
1051 
1052 	/* Push GRE header. */
1053 	proto = (t->parms.erspan_ver == 1) ? htons(ETH_P_ERSPAN)
1054 					   : htons(ETH_P_ERSPAN2);
1055 	gre_build_header(skb, 8, TUNNEL_SEQ, proto, 0, htonl(t->o_seqno++));
1056 
1057 	/* TooBig packet may have updated dst->dev's mtu */
1058 	if (!t->parms.collect_md && dst && dst_mtu(dst) > dst->dev->mtu)
1059 		dst->ops->update_pmtu(dst, NULL, skb, dst->dev->mtu, false);
1060 
1061 	err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
1062 			   NEXTHDR_GRE);
1063 	if (err != 0) {
1064 		/* XXX: send ICMP error even if DF is not set. */
1065 		if (err == -EMSGSIZE) {
1066 			if (skb->protocol == htons(ETH_P_IP))
1067 				icmp_ndo_send(skb, ICMP_DEST_UNREACH,
1068 					      ICMP_FRAG_NEEDED, htonl(mtu));
1069 			else
1070 				icmpv6_ndo_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
1071 		}
1072 
1073 		goto tx_err;
1074 	}
1075 	return NETDEV_TX_OK;
1076 
1077 tx_err:
1078 	stats = &t->dev->stats;
1079 	if (!IS_ERR(tun_info))
1080 		stats->tx_errors++;
1081 	stats->tx_dropped++;
1082 	kfree_skb(skb);
1083 	return NETDEV_TX_OK;
1084 }
1085 
1086 static void ip6gre_tnl_link_config_common(struct ip6_tnl *t)
1087 {
1088 	struct net_device *dev = t->dev;
1089 	struct __ip6_tnl_parm *p = &t->parms;
1090 	struct flowi6 *fl6 = &t->fl.u.ip6;
1091 
1092 	if (dev->type != ARPHRD_ETHER) {
1093 		memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
1094 		memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
1095 	}
1096 
1097 	/* Set up flowi template */
1098 	fl6->saddr = p->laddr;
1099 	fl6->daddr = p->raddr;
1100 	fl6->flowi6_oif = p->link;
1101 	fl6->flowlabel = 0;
1102 	fl6->flowi6_proto = IPPROTO_GRE;
1103 
1104 	if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
1105 		fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
1106 	if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
1107 		fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
1108 
1109 	p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
1110 	p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
1111 
1112 	if (p->flags&IP6_TNL_F_CAP_XMIT &&
1113 			p->flags&IP6_TNL_F_CAP_RCV && dev->type != ARPHRD_ETHER)
1114 		dev->flags |= IFF_POINTOPOINT;
1115 	else
1116 		dev->flags &= ~IFF_POINTOPOINT;
1117 }
1118 
1119 static void ip6gre_tnl_link_config_route(struct ip6_tnl *t, int set_mtu,
1120 					 int t_hlen)
1121 {
1122 	const struct __ip6_tnl_parm *p = &t->parms;
1123 	struct net_device *dev = t->dev;
1124 
1125 	if (p->flags & IP6_TNL_F_CAP_XMIT) {
1126 		int strict = (ipv6_addr_type(&p->raddr) &
1127 			      (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
1128 
1129 		struct rt6_info *rt = rt6_lookup(t->net,
1130 						 &p->raddr, &p->laddr,
1131 						 p->link, NULL, strict);
1132 
1133 		if (!rt)
1134 			return;
1135 
1136 		if (rt->dst.dev) {
1137 			unsigned short dst_len = rt->dst.dev->hard_header_len +
1138 						 t_hlen;
1139 
1140 			if (t->dev->header_ops)
1141 				dev->hard_header_len = dst_len;
1142 			else
1143 				dev->needed_headroom = dst_len;
1144 
1145 			if (set_mtu) {
1146 				dev->mtu = rt->dst.dev->mtu - t_hlen;
1147 				if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1148 					dev->mtu -= 8;
1149 				if (dev->type == ARPHRD_ETHER)
1150 					dev->mtu -= ETH_HLEN;
1151 
1152 				if (dev->mtu < IPV6_MIN_MTU)
1153 					dev->mtu = IPV6_MIN_MTU;
1154 			}
1155 		}
1156 		ip6_rt_put(rt);
1157 	}
1158 }
1159 
1160 static int ip6gre_calc_hlen(struct ip6_tnl *tunnel)
1161 {
1162 	int t_hlen;
1163 
1164 	tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags);
1165 	tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen;
1166 
1167 	t_hlen = tunnel->hlen + sizeof(struct ipv6hdr);
1168 
1169 	if (tunnel->dev->header_ops)
1170 		tunnel->dev->hard_header_len = LL_MAX_HEADER + t_hlen;
1171 	else
1172 		tunnel->dev->needed_headroom = LL_MAX_HEADER + t_hlen;
1173 
1174 	return t_hlen;
1175 }
1176 
1177 static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu)
1178 {
1179 	ip6gre_tnl_link_config_common(t);
1180 	ip6gre_tnl_link_config_route(t, set_mtu, ip6gre_calc_hlen(t));
1181 }
1182 
1183 static void ip6gre_tnl_copy_tnl_parm(struct ip6_tnl *t,
1184 				     const struct __ip6_tnl_parm *p)
1185 {
1186 	t->parms.laddr = p->laddr;
1187 	t->parms.raddr = p->raddr;
1188 	t->parms.flags = p->flags;
1189 	t->parms.hop_limit = p->hop_limit;
1190 	t->parms.encap_limit = p->encap_limit;
1191 	t->parms.flowinfo = p->flowinfo;
1192 	t->parms.link = p->link;
1193 	t->parms.proto = p->proto;
1194 	t->parms.i_key = p->i_key;
1195 	t->parms.o_key = p->o_key;
1196 	t->parms.i_flags = p->i_flags;
1197 	t->parms.o_flags = p->o_flags;
1198 	t->parms.fwmark = p->fwmark;
1199 	t->parms.erspan_ver = p->erspan_ver;
1200 	t->parms.index = p->index;
1201 	t->parms.dir = p->dir;
1202 	t->parms.hwid = p->hwid;
1203 	dst_cache_reset(&t->dst_cache);
1204 }
1205 
1206 static int ip6gre_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p,
1207 			     int set_mtu)
1208 {
1209 	ip6gre_tnl_copy_tnl_parm(t, p);
1210 	ip6gre_tnl_link_config(t, set_mtu);
1211 	return 0;
1212 }
1213 
1214 static void ip6gre_tnl_parm_from_user(struct __ip6_tnl_parm *p,
1215 	const struct ip6_tnl_parm2 *u)
1216 {
1217 	p->laddr = u->laddr;
1218 	p->raddr = u->raddr;
1219 	p->flags = u->flags;
1220 	p->hop_limit = u->hop_limit;
1221 	p->encap_limit = u->encap_limit;
1222 	p->flowinfo = u->flowinfo;
1223 	p->link = u->link;
1224 	p->i_key = u->i_key;
1225 	p->o_key = u->o_key;
1226 	p->i_flags = gre_flags_to_tnl_flags(u->i_flags);
1227 	p->o_flags = gre_flags_to_tnl_flags(u->o_flags);
1228 	memcpy(p->name, u->name, sizeof(u->name));
1229 }
1230 
1231 static void ip6gre_tnl_parm_to_user(struct ip6_tnl_parm2 *u,
1232 	const struct __ip6_tnl_parm *p)
1233 {
1234 	u->proto = IPPROTO_GRE;
1235 	u->laddr = p->laddr;
1236 	u->raddr = p->raddr;
1237 	u->flags = p->flags;
1238 	u->hop_limit = p->hop_limit;
1239 	u->encap_limit = p->encap_limit;
1240 	u->flowinfo = p->flowinfo;
1241 	u->link = p->link;
1242 	u->i_key = p->i_key;
1243 	u->o_key = p->o_key;
1244 	u->i_flags = gre_tnl_flags_to_gre_flags(p->i_flags);
1245 	u->o_flags = gre_tnl_flags_to_gre_flags(p->o_flags);
1246 	memcpy(u->name, p->name, sizeof(u->name));
1247 }
1248 
1249 static int ip6gre_tunnel_siocdevprivate(struct net_device *dev,
1250 					struct ifreq *ifr, void __user *data,
1251 					int cmd)
1252 {
1253 	int err = 0;
1254 	struct ip6_tnl_parm2 p;
1255 	struct __ip6_tnl_parm p1;
1256 	struct ip6_tnl *t = netdev_priv(dev);
1257 	struct net *net = t->net;
1258 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1259 
1260 	memset(&p1, 0, sizeof(p1));
1261 
1262 	switch (cmd) {
1263 	case SIOCGETTUNNEL:
1264 		if (dev == ign->fb_tunnel_dev) {
1265 			if (copy_from_user(&p, data, sizeof(p))) {
1266 				err = -EFAULT;
1267 				break;
1268 			}
1269 			ip6gre_tnl_parm_from_user(&p1, &p);
1270 			t = ip6gre_tunnel_locate(net, &p1, 0);
1271 			if (!t)
1272 				t = netdev_priv(dev);
1273 		}
1274 		memset(&p, 0, sizeof(p));
1275 		ip6gre_tnl_parm_to_user(&p, &t->parms);
1276 		if (copy_to_user(data, &p, sizeof(p)))
1277 			err = -EFAULT;
1278 		break;
1279 
1280 	case SIOCADDTUNNEL:
1281 	case SIOCCHGTUNNEL:
1282 		err = -EPERM;
1283 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1284 			goto done;
1285 
1286 		err = -EFAULT;
1287 		if (copy_from_user(&p, data, sizeof(p)))
1288 			goto done;
1289 
1290 		err = -EINVAL;
1291 		if ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING))
1292 			goto done;
1293 
1294 		if (!(p.i_flags&GRE_KEY))
1295 			p.i_key = 0;
1296 		if (!(p.o_flags&GRE_KEY))
1297 			p.o_key = 0;
1298 
1299 		ip6gre_tnl_parm_from_user(&p1, &p);
1300 		t = ip6gre_tunnel_locate(net, &p1, cmd == SIOCADDTUNNEL);
1301 
1302 		if (dev != ign->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
1303 			if (t) {
1304 				if (t->dev != dev) {
1305 					err = -EEXIST;
1306 					break;
1307 				}
1308 			} else {
1309 				t = netdev_priv(dev);
1310 
1311 				ip6gre_tunnel_unlink(ign, t);
1312 				synchronize_net();
1313 				ip6gre_tnl_change(t, &p1, 1);
1314 				ip6gre_tunnel_link(ign, t);
1315 				netdev_state_change(dev);
1316 			}
1317 		}
1318 
1319 		if (t) {
1320 			err = 0;
1321 
1322 			memset(&p, 0, sizeof(p));
1323 			ip6gre_tnl_parm_to_user(&p, &t->parms);
1324 			if (copy_to_user(data, &p, sizeof(p)))
1325 				err = -EFAULT;
1326 		} else
1327 			err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1328 		break;
1329 
1330 	case SIOCDELTUNNEL:
1331 		err = -EPERM;
1332 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1333 			goto done;
1334 
1335 		if (dev == ign->fb_tunnel_dev) {
1336 			err = -EFAULT;
1337 			if (copy_from_user(&p, data, sizeof(p)))
1338 				goto done;
1339 			err = -ENOENT;
1340 			ip6gre_tnl_parm_from_user(&p1, &p);
1341 			t = ip6gre_tunnel_locate(net, &p1, 0);
1342 			if (!t)
1343 				goto done;
1344 			err = -EPERM;
1345 			if (t == netdev_priv(ign->fb_tunnel_dev))
1346 				goto done;
1347 			dev = t->dev;
1348 		}
1349 		unregister_netdevice(dev);
1350 		err = 0;
1351 		break;
1352 
1353 	default:
1354 		err = -EINVAL;
1355 	}
1356 
1357 done:
1358 	return err;
1359 }
1360 
1361 static int ip6gre_header(struct sk_buff *skb, struct net_device *dev,
1362 			 unsigned short type, const void *daddr,
1363 			 const void *saddr, unsigned int len)
1364 {
1365 	struct ip6_tnl *t = netdev_priv(dev);
1366 	struct ipv6hdr *ipv6h;
1367 	__be16 *p;
1368 
1369 	ipv6h = skb_push(skb, t->hlen + sizeof(*ipv6h));
1370 	ip6_flow_hdr(ipv6h, 0, ip6_make_flowlabel(dev_net(dev), skb,
1371 						  t->fl.u.ip6.flowlabel,
1372 						  true, &t->fl.u.ip6));
1373 	ipv6h->hop_limit = t->parms.hop_limit;
1374 	ipv6h->nexthdr = NEXTHDR_GRE;
1375 	ipv6h->saddr = t->parms.laddr;
1376 	ipv6h->daddr = t->parms.raddr;
1377 
1378 	p = (__be16 *)(ipv6h + 1);
1379 	p[0] = t->parms.o_flags;
1380 	p[1] = htons(type);
1381 
1382 	/*
1383 	 *	Set the source hardware address.
1384 	 */
1385 
1386 	if (saddr)
1387 		memcpy(&ipv6h->saddr, saddr, sizeof(struct in6_addr));
1388 	if (daddr)
1389 		memcpy(&ipv6h->daddr, daddr, sizeof(struct in6_addr));
1390 	if (!ipv6_addr_any(&ipv6h->daddr))
1391 		return t->hlen;
1392 
1393 	return -t->hlen;
1394 }
1395 
1396 static const struct header_ops ip6gre_header_ops = {
1397 	.create	= ip6gre_header,
1398 };
1399 
1400 static const struct net_device_ops ip6gre_netdev_ops = {
1401 	.ndo_init		= ip6gre_tunnel_init,
1402 	.ndo_uninit		= ip6gre_tunnel_uninit,
1403 	.ndo_start_xmit		= ip6gre_tunnel_xmit,
1404 	.ndo_siocdevprivate	= ip6gre_tunnel_siocdevprivate,
1405 	.ndo_change_mtu		= ip6_tnl_change_mtu,
1406 	.ndo_get_stats64	= dev_get_tstats64,
1407 	.ndo_get_iflink		= ip6_tnl_get_iflink,
1408 };
1409 
1410 static void ip6gre_dev_free(struct net_device *dev)
1411 {
1412 	struct ip6_tnl *t = netdev_priv(dev);
1413 
1414 	gro_cells_destroy(&t->gro_cells);
1415 	dst_cache_destroy(&t->dst_cache);
1416 	free_percpu(dev->tstats);
1417 }
1418 
1419 static void ip6gre_tunnel_setup(struct net_device *dev)
1420 {
1421 	dev->netdev_ops = &ip6gre_netdev_ops;
1422 	dev->needs_free_netdev = true;
1423 	dev->priv_destructor = ip6gre_dev_free;
1424 
1425 	dev->type = ARPHRD_IP6GRE;
1426 
1427 	dev->flags |= IFF_NOARP;
1428 	dev->addr_len = sizeof(struct in6_addr);
1429 	netif_keep_dst(dev);
1430 	/* This perm addr will be used as interface identifier by IPv6 */
1431 	dev->addr_assign_type = NET_ADDR_RANDOM;
1432 	eth_random_addr(dev->perm_addr);
1433 }
1434 
1435 #define GRE6_FEATURES (NETIF_F_SG |		\
1436 		       NETIF_F_FRAGLIST |	\
1437 		       NETIF_F_HIGHDMA |	\
1438 		       NETIF_F_HW_CSUM)
1439 
1440 static void ip6gre_tnl_init_features(struct net_device *dev)
1441 {
1442 	struct ip6_tnl *nt = netdev_priv(dev);
1443 
1444 	dev->features		|= GRE6_FEATURES;
1445 	dev->hw_features	|= GRE6_FEATURES;
1446 
1447 	if (!(nt->parms.o_flags & TUNNEL_SEQ)) {
1448 		/* TCP offload with GRE SEQ is not supported, nor
1449 		 * can we support 2 levels of outer headers requiring
1450 		 * an update.
1451 		 */
1452 		if (!(nt->parms.o_flags & TUNNEL_CSUM) ||
1453 		    nt->encap.type == TUNNEL_ENCAP_NONE) {
1454 			dev->features    |= NETIF_F_GSO_SOFTWARE;
1455 			dev->hw_features |= NETIF_F_GSO_SOFTWARE;
1456 		}
1457 
1458 		/* Can use a lockless transmit, unless we generate
1459 		 * output sequences
1460 		 */
1461 		dev->features |= NETIF_F_LLTX;
1462 	}
1463 }
1464 
1465 static int ip6gre_tunnel_init_common(struct net_device *dev)
1466 {
1467 	struct ip6_tnl *tunnel;
1468 	int ret;
1469 	int t_hlen;
1470 
1471 	tunnel = netdev_priv(dev);
1472 
1473 	tunnel->dev = dev;
1474 	tunnel->net = dev_net(dev);
1475 	strcpy(tunnel->parms.name, dev->name);
1476 
1477 	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1478 	if (!dev->tstats)
1479 		return -ENOMEM;
1480 
1481 	ret = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL);
1482 	if (ret)
1483 		goto cleanup_alloc_pcpu_stats;
1484 
1485 	ret = gro_cells_init(&tunnel->gro_cells, dev);
1486 	if (ret)
1487 		goto cleanup_dst_cache_init;
1488 
1489 	t_hlen = ip6gre_calc_hlen(tunnel);
1490 	dev->mtu = ETH_DATA_LEN - t_hlen;
1491 	if (dev->type == ARPHRD_ETHER)
1492 		dev->mtu -= ETH_HLEN;
1493 	if (!(tunnel->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1494 		dev->mtu -= 8;
1495 
1496 	if (tunnel->parms.collect_md) {
1497 		netif_keep_dst(dev);
1498 	}
1499 	ip6gre_tnl_init_features(dev);
1500 
1501 	dev_hold(dev);
1502 	return 0;
1503 
1504 cleanup_dst_cache_init:
1505 	dst_cache_destroy(&tunnel->dst_cache);
1506 cleanup_alloc_pcpu_stats:
1507 	free_percpu(dev->tstats);
1508 	dev->tstats = NULL;
1509 	return ret;
1510 }
1511 
1512 static int ip6gre_tunnel_init(struct net_device *dev)
1513 {
1514 	struct ip6_tnl *tunnel;
1515 	int ret;
1516 
1517 	ret = ip6gre_tunnel_init_common(dev);
1518 	if (ret)
1519 		return ret;
1520 
1521 	tunnel = netdev_priv(dev);
1522 
1523 	if (tunnel->parms.collect_md)
1524 		return 0;
1525 
1526 	memcpy(dev->dev_addr, &tunnel->parms.laddr, sizeof(struct in6_addr));
1527 	memcpy(dev->broadcast, &tunnel->parms.raddr, sizeof(struct in6_addr));
1528 
1529 	if (ipv6_addr_any(&tunnel->parms.raddr))
1530 		dev->header_ops = &ip6gre_header_ops;
1531 
1532 	return 0;
1533 }
1534 
1535 static void ip6gre_fb_tunnel_init(struct net_device *dev)
1536 {
1537 	struct ip6_tnl *tunnel = netdev_priv(dev);
1538 
1539 	tunnel->dev = dev;
1540 	tunnel->net = dev_net(dev);
1541 	strcpy(tunnel->parms.name, dev->name);
1542 
1543 	tunnel->hlen		= sizeof(struct ipv6hdr) + 4;
1544 }
1545 
1546 static struct inet6_protocol ip6gre_protocol __read_mostly = {
1547 	.handler     = gre_rcv,
1548 	.err_handler = ip6gre_err,
1549 	.flags       = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1550 };
1551 
1552 static void ip6gre_destroy_tunnels(struct net *net, struct list_head *head)
1553 {
1554 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1555 	struct net_device *dev, *aux;
1556 	int prio;
1557 
1558 	for_each_netdev_safe(net, dev, aux)
1559 		if (dev->rtnl_link_ops == &ip6gre_link_ops ||
1560 		    dev->rtnl_link_ops == &ip6gre_tap_ops ||
1561 		    dev->rtnl_link_ops == &ip6erspan_tap_ops)
1562 			unregister_netdevice_queue(dev, head);
1563 
1564 	for (prio = 0; prio < 4; prio++) {
1565 		int h;
1566 		for (h = 0; h < IP6_GRE_HASH_SIZE; h++) {
1567 			struct ip6_tnl *t;
1568 
1569 			t = rtnl_dereference(ign->tunnels[prio][h]);
1570 
1571 			while (t) {
1572 				/* If dev is in the same netns, it has already
1573 				 * been added to the list by the previous loop.
1574 				 */
1575 				if (!net_eq(dev_net(t->dev), net))
1576 					unregister_netdevice_queue(t->dev,
1577 								   head);
1578 				t = rtnl_dereference(t->next);
1579 			}
1580 		}
1581 	}
1582 }
1583 
1584 static int __net_init ip6gre_init_net(struct net *net)
1585 {
1586 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1587 	struct net_device *ndev;
1588 	int err;
1589 
1590 	if (!net_has_fallback_tunnels(net))
1591 		return 0;
1592 	ndev = alloc_netdev(sizeof(struct ip6_tnl), "ip6gre0",
1593 			    NET_NAME_UNKNOWN, ip6gre_tunnel_setup);
1594 	if (!ndev) {
1595 		err = -ENOMEM;
1596 		goto err_alloc_dev;
1597 	}
1598 	ign->fb_tunnel_dev = ndev;
1599 	dev_net_set(ign->fb_tunnel_dev, net);
1600 	/* FB netdevice is special: we have one, and only one per netns.
1601 	 * Allowing to move it to another netns is clearly unsafe.
1602 	 */
1603 	ign->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
1604 
1605 
1606 	ip6gre_fb_tunnel_init(ign->fb_tunnel_dev);
1607 	ign->fb_tunnel_dev->rtnl_link_ops = &ip6gre_link_ops;
1608 
1609 	err = register_netdev(ign->fb_tunnel_dev);
1610 	if (err)
1611 		goto err_reg_dev;
1612 
1613 	rcu_assign_pointer(ign->tunnels_wc[0],
1614 			   netdev_priv(ign->fb_tunnel_dev));
1615 	return 0;
1616 
1617 err_reg_dev:
1618 	free_netdev(ndev);
1619 err_alloc_dev:
1620 	return err;
1621 }
1622 
1623 static void __net_exit ip6gre_exit_batch_net(struct list_head *net_list)
1624 {
1625 	struct net *net;
1626 	LIST_HEAD(list);
1627 
1628 	rtnl_lock();
1629 	list_for_each_entry(net, net_list, exit_list)
1630 		ip6gre_destroy_tunnels(net, &list);
1631 	unregister_netdevice_many(&list);
1632 	rtnl_unlock();
1633 }
1634 
1635 static struct pernet_operations ip6gre_net_ops = {
1636 	.init = ip6gre_init_net,
1637 	.exit_batch = ip6gre_exit_batch_net,
1638 	.id   = &ip6gre_net_id,
1639 	.size = sizeof(struct ip6gre_net),
1640 };
1641 
1642 static int ip6gre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[],
1643 				  struct netlink_ext_ack *extack)
1644 {
1645 	__be16 flags;
1646 
1647 	if (!data)
1648 		return 0;
1649 
1650 	flags = 0;
1651 	if (data[IFLA_GRE_IFLAGS])
1652 		flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1653 	if (data[IFLA_GRE_OFLAGS])
1654 		flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1655 	if (flags & (GRE_VERSION|GRE_ROUTING))
1656 		return -EINVAL;
1657 
1658 	return 0;
1659 }
1660 
1661 static int ip6gre_tap_validate(struct nlattr *tb[], struct nlattr *data[],
1662 			       struct netlink_ext_ack *extack)
1663 {
1664 	struct in6_addr daddr;
1665 
1666 	if (tb[IFLA_ADDRESS]) {
1667 		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1668 			return -EINVAL;
1669 		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1670 			return -EADDRNOTAVAIL;
1671 	}
1672 
1673 	if (!data)
1674 		goto out;
1675 
1676 	if (data[IFLA_GRE_REMOTE]) {
1677 		daddr = nla_get_in6_addr(data[IFLA_GRE_REMOTE]);
1678 		if (ipv6_addr_any(&daddr))
1679 			return -EINVAL;
1680 	}
1681 
1682 out:
1683 	return ip6gre_tunnel_validate(tb, data, extack);
1684 }
1685 
1686 static int ip6erspan_tap_validate(struct nlattr *tb[], struct nlattr *data[],
1687 				  struct netlink_ext_ack *extack)
1688 {
1689 	__be16 flags = 0;
1690 	int ret, ver = 0;
1691 
1692 	if (!data)
1693 		return 0;
1694 
1695 	ret = ip6gre_tap_validate(tb, data, extack);
1696 	if (ret)
1697 		return ret;
1698 
1699 	/* ERSPAN should only have GRE sequence and key flag */
1700 	if (data[IFLA_GRE_OFLAGS])
1701 		flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1702 	if (data[IFLA_GRE_IFLAGS])
1703 		flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1704 	if (!data[IFLA_GRE_COLLECT_METADATA] &&
1705 	    flags != (GRE_SEQ | GRE_KEY))
1706 		return -EINVAL;
1707 
1708 	/* ERSPAN Session ID only has 10-bit. Since we reuse
1709 	 * 32-bit key field as ID, check it's range.
1710 	 */
1711 	if (data[IFLA_GRE_IKEY] &&
1712 	    (ntohl(nla_get_be32(data[IFLA_GRE_IKEY])) & ~ID_MASK))
1713 		return -EINVAL;
1714 
1715 	if (data[IFLA_GRE_OKEY] &&
1716 	    (ntohl(nla_get_be32(data[IFLA_GRE_OKEY])) & ~ID_MASK))
1717 		return -EINVAL;
1718 
1719 	if (data[IFLA_GRE_ERSPAN_VER]) {
1720 		ver = nla_get_u8(data[IFLA_GRE_ERSPAN_VER]);
1721 		if (ver != 1 && ver != 2)
1722 			return -EINVAL;
1723 	}
1724 
1725 	if (ver == 1) {
1726 		if (data[IFLA_GRE_ERSPAN_INDEX]) {
1727 			u32 index = nla_get_u32(data[IFLA_GRE_ERSPAN_INDEX]);
1728 
1729 			if (index & ~INDEX_MASK)
1730 				return -EINVAL;
1731 		}
1732 	} else if (ver == 2) {
1733 		if (data[IFLA_GRE_ERSPAN_DIR]) {
1734 			u16 dir = nla_get_u8(data[IFLA_GRE_ERSPAN_DIR]);
1735 
1736 			if (dir & ~(DIR_MASK >> DIR_OFFSET))
1737 				return -EINVAL;
1738 		}
1739 
1740 		if (data[IFLA_GRE_ERSPAN_HWID]) {
1741 			u16 hwid = nla_get_u16(data[IFLA_GRE_ERSPAN_HWID]);
1742 
1743 			if (hwid & ~(HWID_MASK >> HWID_OFFSET))
1744 				return -EINVAL;
1745 		}
1746 	}
1747 
1748 	return 0;
1749 }
1750 
1751 static void ip6erspan_set_version(struct nlattr *data[],
1752 				  struct __ip6_tnl_parm *parms)
1753 {
1754 	if (!data)
1755 		return;
1756 
1757 	parms->erspan_ver = 1;
1758 	if (data[IFLA_GRE_ERSPAN_VER])
1759 		parms->erspan_ver = nla_get_u8(data[IFLA_GRE_ERSPAN_VER]);
1760 
1761 	if (parms->erspan_ver == 1) {
1762 		if (data[IFLA_GRE_ERSPAN_INDEX])
1763 			parms->index = nla_get_u32(data[IFLA_GRE_ERSPAN_INDEX]);
1764 	} else if (parms->erspan_ver == 2) {
1765 		if (data[IFLA_GRE_ERSPAN_DIR])
1766 			parms->dir = nla_get_u8(data[IFLA_GRE_ERSPAN_DIR]);
1767 		if (data[IFLA_GRE_ERSPAN_HWID])
1768 			parms->hwid = nla_get_u16(data[IFLA_GRE_ERSPAN_HWID]);
1769 	}
1770 }
1771 
1772 static void ip6gre_netlink_parms(struct nlattr *data[],
1773 				struct __ip6_tnl_parm *parms)
1774 {
1775 	memset(parms, 0, sizeof(*parms));
1776 
1777 	if (!data)
1778 		return;
1779 
1780 	if (data[IFLA_GRE_LINK])
1781 		parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
1782 
1783 	if (data[IFLA_GRE_IFLAGS])
1784 		parms->i_flags = gre_flags_to_tnl_flags(
1785 				nla_get_be16(data[IFLA_GRE_IFLAGS]));
1786 
1787 	if (data[IFLA_GRE_OFLAGS])
1788 		parms->o_flags = gre_flags_to_tnl_flags(
1789 				nla_get_be16(data[IFLA_GRE_OFLAGS]));
1790 
1791 	if (data[IFLA_GRE_IKEY])
1792 		parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
1793 
1794 	if (data[IFLA_GRE_OKEY])
1795 		parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
1796 
1797 	if (data[IFLA_GRE_LOCAL])
1798 		parms->laddr = nla_get_in6_addr(data[IFLA_GRE_LOCAL]);
1799 
1800 	if (data[IFLA_GRE_REMOTE])
1801 		parms->raddr = nla_get_in6_addr(data[IFLA_GRE_REMOTE]);
1802 
1803 	if (data[IFLA_GRE_TTL])
1804 		parms->hop_limit = nla_get_u8(data[IFLA_GRE_TTL]);
1805 
1806 	if (data[IFLA_GRE_ENCAP_LIMIT])
1807 		parms->encap_limit = nla_get_u8(data[IFLA_GRE_ENCAP_LIMIT]);
1808 
1809 	if (data[IFLA_GRE_FLOWINFO])
1810 		parms->flowinfo = nla_get_be32(data[IFLA_GRE_FLOWINFO]);
1811 
1812 	if (data[IFLA_GRE_FLAGS])
1813 		parms->flags = nla_get_u32(data[IFLA_GRE_FLAGS]);
1814 
1815 	if (data[IFLA_GRE_FWMARK])
1816 		parms->fwmark = nla_get_u32(data[IFLA_GRE_FWMARK]);
1817 
1818 	if (data[IFLA_GRE_COLLECT_METADATA])
1819 		parms->collect_md = true;
1820 }
1821 
1822 static int ip6gre_tap_init(struct net_device *dev)
1823 {
1824 	int ret;
1825 
1826 	ret = ip6gre_tunnel_init_common(dev);
1827 	if (ret)
1828 		return ret;
1829 
1830 	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1831 
1832 	return 0;
1833 }
1834 
1835 static const struct net_device_ops ip6gre_tap_netdev_ops = {
1836 	.ndo_init = ip6gre_tap_init,
1837 	.ndo_uninit = ip6gre_tunnel_uninit,
1838 	.ndo_start_xmit = ip6gre_tunnel_xmit,
1839 	.ndo_set_mac_address = eth_mac_addr,
1840 	.ndo_validate_addr = eth_validate_addr,
1841 	.ndo_change_mtu = ip6_tnl_change_mtu,
1842 	.ndo_get_stats64 = dev_get_tstats64,
1843 	.ndo_get_iflink = ip6_tnl_get_iflink,
1844 };
1845 
1846 static int ip6erspan_calc_hlen(struct ip6_tnl *tunnel)
1847 {
1848 	int t_hlen;
1849 
1850 	tunnel->tun_hlen = 8;
1851 	tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen +
1852 		       erspan_hdr_len(tunnel->parms.erspan_ver);
1853 
1854 	t_hlen = tunnel->hlen + sizeof(struct ipv6hdr);
1855 	tunnel->dev->needed_headroom = LL_MAX_HEADER + t_hlen;
1856 	return t_hlen;
1857 }
1858 
1859 static int ip6erspan_tap_init(struct net_device *dev)
1860 {
1861 	struct ip6_tnl *tunnel;
1862 	int t_hlen;
1863 	int ret;
1864 
1865 	tunnel = netdev_priv(dev);
1866 
1867 	tunnel->dev = dev;
1868 	tunnel->net = dev_net(dev);
1869 	strcpy(tunnel->parms.name, dev->name);
1870 
1871 	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1872 	if (!dev->tstats)
1873 		return -ENOMEM;
1874 
1875 	ret = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL);
1876 	if (ret)
1877 		goto cleanup_alloc_pcpu_stats;
1878 
1879 	ret = gro_cells_init(&tunnel->gro_cells, dev);
1880 	if (ret)
1881 		goto cleanup_dst_cache_init;
1882 
1883 	t_hlen = ip6erspan_calc_hlen(tunnel);
1884 	dev->mtu = ETH_DATA_LEN - t_hlen;
1885 	if (dev->type == ARPHRD_ETHER)
1886 		dev->mtu -= ETH_HLEN;
1887 	if (!(tunnel->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1888 		dev->mtu -= 8;
1889 
1890 	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1891 	ip6erspan_tnl_link_config(tunnel, 1);
1892 
1893 	dev_hold(dev);
1894 	return 0;
1895 
1896 cleanup_dst_cache_init:
1897 	dst_cache_destroy(&tunnel->dst_cache);
1898 cleanup_alloc_pcpu_stats:
1899 	free_percpu(dev->tstats);
1900 	dev->tstats = NULL;
1901 	return ret;
1902 }
1903 
1904 static const struct net_device_ops ip6erspan_netdev_ops = {
1905 	.ndo_init =		ip6erspan_tap_init,
1906 	.ndo_uninit =		ip6erspan_tunnel_uninit,
1907 	.ndo_start_xmit =	ip6erspan_tunnel_xmit,
1908 	.ndo_set_mac_address =	eth_mac_addr,
1909 	.ndo_validate_addr =	eth_validate_addr,
1910 	.ndo_change_mtu =	ip6_tnl_change_mtu,
1911 	.ndo_get_stats64 =	dev_get_tstats64,
1912 	.ndo_get_iflink =	ip6_tnl_get_iflink,
1913 };
1914 
1915 static void ip6gre_tap_setup(struct net_device *dev)
1916 {
1917 
1918 	ether_setup(dev);
1919 
1920 	dev->max_mtu = 0;
1921 	dev->netdev_ops = &ip6gre_tap_netdev_ops;
1922 	dev->needs_free_netdev = true;
1923 	dev->priv_destructor = ip6gre_dev_free;
1924 
1925 	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1926 	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1927 	netif_keep_dst(dev);
1928 }
1929 
1930 static bool ip6gre_netlink_encap_parms(struct nlattr *data[],
1931 				       struct ip_tunnel_encap *ipencap)
1932 {
1933 	bool ret = false;
1934 
1935 	memset(ipencap, 0, sizeof(*ipencap));
1936 
1937 	if (!data)
1938 		return ret;
1939 
1940 	if (data[IFLA_GRE_ENCAP_TYPE]) {
1941 		ret = true;
1942 		ipencap->type = nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]);
1943 	}
1944 
1945 	if (data[IFLA_GRE_ENCAP_FLAGS]) {
1946 		ret = true;
1947 		ipencap->flags = nla_get_u16(data[IFLA_GRE_ENCAP_FLAGS]);
1948 	}
1949 
1950 	if (data[IFLA_GRE_ENCAP_SPORT]) {
1951 		ret = true;
1952 		ipencap->sport = nla_get_be16(data[IFLA_GRE_ENCAP_SPORT]);
1953 	}
1954 
1955 	if (data[IFLA_GRE_ENCAP_DPORT]) {
1956 		ret = true;
1957 		ipencap->dport = nla_get_be16(data[IFLA_GRE_ENCAP_DPORT]);
1958 	}
1959 
1960 	return ret;
1961 }
1962 
1963 static int ip6gre_newlink_common(struct net *src_net, struct net_device *dev,
1964 				 struct nlattr *tb[], struct nlattr *data[],
1965 				 struct netlink_ext_ack *extack)
1966 {
1967 	struct ip6_tnl *nt;
1968 	struct ip_tunnel_encap ipencap;
1969 	int err;
1970 
1971 	nt = netdev_priv(dev);
1972 
1973 	if (ip6gre_netlink_encap_parms(data, &ipencap)) {
1974 		int err = ip6_tnl_encap_setup(nt, &ipencap);
1975 
1976 		if (err < 0)
1977 			return err;
1978 	}
1979 
1980 	if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
1981 		eth_hw_addr_random(dev);
1982 
1983 	nt->dev = dev;
1984 	nt->net = dev_net(dev);
1985 
1986 	err = register_netdevice(dev);
1987 	if (err)
1988 		goto out;
1989 
1990 	if (tb[IFLA_MTU])
1991 		ip6_tnl_change_mtu(dev, nla_get_u32(tb[IFLA_MTU]));
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