xref: /linux/net/ipv6/ip6_gre.c (revision 3f41368fbfe1b3d5922d317fe1a0a0cab6846802)
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 		strscpy(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 	ip6gre_tunnel_link(ign, nt);
386 	return nt;
387 
388 failed_free:
389 	free_netdev(dev);
390 	return NULL;
391 }
392 
393 static void ip6erspan_tunnel_uninit(struct net_device *dev)
394 {
395 	struct ip6_tnl *t = netdev_priv(dev);
396 	struct ip6gre_net *ign = net_generic(t->net, ip6gre_net_id);
397 
398 	ip6erspan_tunnel_unlink_md(ign, t);
399 	ip6gre_tunnel_unlink(ign, t);
400 	dst_cache_reset(&t->dst_cache);
401 	netdev_put(dev, &t->dev_tracker);
402 }
403 
404 static void ip6gre_tunnel_uninit(struct net_device *dev)
405 {
406 	struct ip6_tnl *t = netdev_priv(dev);
407 	struct ip6gre_net *ign = net_generic(t->net, ip6gre_net_id);
408 
409 	ip6gre_tunnel_unlink_md(ign, t);
410 	ip6gre_tunnel_unlink(ign, t);
411 	if (ign->fb_tunnel_dev == dev)
412 		WRITE_ONCE(ign->fb_tunnel_dev, NULL);
413 	dst_cache_reset(&t->dst_cache);
414 	netdev_put(dev, &t->dev_tracker);
415 }
416 
417 
418 static int ip6gre_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
419 		       u8 type, u8 code, int offset, __be32 info)
420 {
421 	struct net *net = dev_net(skb->dev);
422 	const struct ipv6hdr *ipv6h;
423 	struct tnl_ptk_info tpi;
424 	struct ip6_tnl *t;
425 
426 	if (gre_parse_header(skb, &tpi, NULL, htons(ETH_P_IPV6),
427 			     offset) < 0)
428 		return -EINVAL;
429 
430 	ipv6h = (const struct ipv6hdr *)skb->data;
431 	t = ip6gre_tunnel_lookup(skb->dev, &ipv6h->daddr, &ipv6h->saddr,
432 				 tpi.key, tpi.proto);
433 	if (!t)
434 		return -ENOENT;
435 
436 	switch (type) {
437 	case ICMPV6_DEST_UNREACH:
438 		net_dbg_ratelimited("%s: Path to destination invalid or inactive!\n",
439 				    t->parms.name);
440 		if (code != ICMPV6_PORT_UNREACH)
441 			break;
442 		return 0;
443 	case ICMPV6_TIME_EXCEED:
444 		if (code == ICMPV6_EXC_HOPLIMIT) {
445 			net_dbg_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
446 					    t->parms.name);
447 			break;
448 		}
449 		return 0;
450 	case ICMPV6_PARAMPROB: {
451 		struct ipv6_tlv_tnl_enc_lim *tel;
452 		__u32 teli;
453 
454 		teli = 0;
455 		if (code == ICMPV6_HDR_FIELD)
456 			teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
457 
458 		if (teli && teli == be32_to_cpu(info) - 2) {
459 			tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
460 			if (tel->encap_limit == 0) {
461 				net_dbg_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
462 						    t->parms.name);
463 			}
464 		} else {
465 			net_dbg_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
466 					    t->parms.name);
467 		}
468 		return 0;
469 	}
470 	case ICMPV6_PKT_TOOBIG:
471 		ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL));
472 		return 0;
473 	case NDISC_REDIRECT:
474 		ip6_redirect(skb, net, skb->dev->ifindex, 0,
475 			     sock_net_uid(net, NULL));
476 		return 0;
477 	}
478 
479 	if (time_before(jiffies, t->err_time + IP6TUNNEL_ERR_TIMEO))
480 		t->err_count++;
481 	else
482 		t->err_count = 1;
483 	t->err_time = jiffies;
484 
485 	return 0;
486 }
487 
488 static int ip6gre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi)
489 {
490 	const struct ipv6hdr *ipv6h;
491 	struct ip6_tnl *tunnel;
492 
493 	ipv6h = ipv6_hdr(skb);
494 	tunnel = ip6gre_tunnel_lookup(skb->dev,
495 				      &ipv6h->saddr, &ipv6h->daddr, tpi->key,
496 				      tpi->proto);
497 	if (tunnel) {
498 		if (tunnel->parms.collect_md) {
499 			IP_TUNNEL_DECLARE_FLAGS(flags);
500 			struct metadata_dst *tun_dst;
501 			__be64 tun_id;
502 
503 			ip_tunnel_flags_copy(flags, tpi->flags);
504 			tun_id = key32_to_tunnel_id(tpi->key);
505 
506 			tun_dst = ipv6_tun_rx_dst(skb, flags, tun_id, 0);
507 			if (!tun_dst)
508 				return PACKET_REJECT;
509 
510 			ip6_tnl_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error);
511 		} else {
512 			ip6_tnl_rcv(tunnel, skb, tpi, NULL, log_ecn_error);
513 		}
514 
515 		return PACKET_RCVD;
516 	}
517 
518 	return PACKET_REJECT;
519 }
520 
521 static int ip6erspan_rcv(struct sk_buff *skb,
522 			 struct tnl_ptk_info *tpi,
523 			 int gre_hdr_len)
524 {
525 	struct erspan_base_hdr *ershdr;
526 	const struct ipv6hdr *ipv6h;
527 	struct erspan_md2 *md2;
528 	struct ip6_tnl *tunnel;
529 	u8 ver;
530 
531 	if (unlikely(!pskb_may_pull(skb, sizeof(*ershdr))))
532 		return PACKET_REJECT;
533 
534 	ipv6h = ipv6_hdr(skb);
535 	ershdr = (struct erspan_base_hdr *)skb->data;
536 	ver = ershdr->ver;
537 
538 	tunnel = ip6gre_tunnel_lookup(skb->dev,
539 				      &ipv6h->saddr, &ipv6h->daddr, tpi->key,
540 				      tpi->proto);
541 	if (tunnel) {
542 		int len = erspan_hdr_len(ver);
543 
544 		if (unlikely(!pskb_may_pull(skb, len)))
545 			return PACKET_REJECT;
546 
547 		if (__iptunnel_pull_header(skb, len,
548 					   htons(ETH_P_TEB),
549 					   false, false) < 0)
550 			return PACKET_REJECT;
551 
552 		if (tunnel->parms.collect_md) {
553 			struct erspan_metadata *pkt_md, *md;
554 			IP_TUNNEL_DECLARE_FLAGS(flags);
555 			struct metadata_dst *tun_dst;
556 			struct ip_tunnel_info *info;
557 			unsigned char *gh;
558 			__be64 tun_id;
559 
560 			__set_bit(IP_TUNNEL_KEY_BIT, tpi->flags);
561 			ip_tunnel_flags_copy(flags, tpi->flags);
562 			tun_id = key32_to_tunnel_id(tpi->key);
563 
564 			tun_dst = ipv6_tun_rx_dst(skb, flags, tun_id,
565 						  sizeof(*md));
566 			if (!tun_dst)
567 				return PACKET_REJECT;
568 
569 			/* skb can be uncloned in __iptunnel_pull_header, so
570 			 * old pkt_md is no longer valid and we need to reset
571 			 * it
572 			 */
573 			gh = skb_network_header(skb) +
574 			     skb_network_header_len(skb);
575 			pkt_md = (struct erspan_metadata *)(gh + gre_hdr_len +
576 							    sizeof(*ershdr));
577 			info = &tun_dst->u.tun_info;
578 			md = ip_tunnel_info_opts(info);
579 			md->version = ver;
580 			md2 = &md->u.md2;
581 			memcpy(md2, pkt_md, ver == 1 ? ERSPAN_V1_MDSIZE :
582 						       ERSPAN_V2_MDSIZE);
583 			__set_bit(IP_TUNNEL_ERSPAN_OPT_BIT,
584 				  info->key.tun_flags);
585 			info->options_len = sizeof(*md);
586 
587 			ip6_tnl_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error);
588 
589 		} else {
590 			ip6_tnl_rcv(tunnel, skb, tpi, NULL, log_ecn_error);
591 		}
592 
593 		return PACKET_RCVD;
594 	}
595 
596 	return PACKET_REJECT;
597 }
598 
599 static int gre_rcv(struct sk_buff *skb)
600 {
601 	struct tnl_ptk_info tpi;
602 	bool csum_err = false;
603 	int hdr_len;
604 
605 	hdr_len = gre_parse_header(skb, &tpi, &csum_err, htons(ETH_P_IPV6), 0);
606 	if (hdr_len < 0)
607 		goto drop;
608 
609 	if (iptunnel_pull_header(skb, hdr_len, tpi.proto, false))
610 		goto drop;
611 
612 	if (unlikely(tpi.proto == htons(ETH_P_ERSPAN) ||
613 		     tpi.proto == htons(ETH_P_ERSPAN2))) {
614 		if (ip6erspan_rcv(skb, &tpi, hdr_len) == PACKET_RCVD)
615 			return 0;
616 		goto out;
617 	}
618 
619 	if (ip6gre_rcv(skb, &tpi) == PACKET_RCVD)
620 		return 0;
621 
622 out:
623 	icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
624 drop:
625 	kfree_skb(skb);
626 	return 0;
627 }
628 
629 static int gre_handle_offloads(struct sk_buff *skb, bool csum)
630 {
631 	return iptunnel_handle_offloads(skb,
632 					csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE);
633 }
634 
635 static void prepare_ip6gre_xmit_ipv4(struct sk_buff *skb,
636 				     struct net_device *dev,
637 				     struct flowi6 *fl6, __u8 *dsfield,
638 				     int *encap_limit)
639 {
640 	const struct iphdr *iph = ip_hdr(skb);
641 	struct ip6_tnl *t = netdev_priv(dev);
642 
643 	if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
644 		*encap_limit = t->parms.encap_limit;
645 
646 	memcpy(fl6, &t->fl.u.ip6, sizeof(*fl6));
647 
648 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
649 		*dsfield = ipv4_get_dsfield(iph);
650 	else
651 		*dsfield = ip6_tclass(t->parms.flowinfo);
652 
653 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
654 		fl6->flowi6_mark = skb->mark;
655 	else
656 		fl6->flowi6_mark = t->parms.fwmark;
657 
658 	fl6->flowi6_uid = sock_net_uid(dev_net(dev), NULL);
659 }
660 
661 static int prepare_ip6gre_xmit_ipv6(struct sk_buff *skb,
662 				    struct net_device *dev,
663 				    struct flowi6 *fl6, __u8 *dsfield,
664 				    int *encap_limit)
665 {
666 	struct ipv6hdr *ipv6h;
667 	struct ip6_tnl *t = netdev_priv(dev);
668 	__u16 offset;
669 
670 	offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
671 	/* ip6_tnl_parse_tlv_enc_lim() might have reallocated skb->head */
672 	ipv6h = ipv6_hdr(skb);
673 
674 	if (offset > 0) {
675 		struct ipv6_tlv_tnl_enc_lim *tel;
676 
677 		tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset];
678 		if (tel->encap_limit == 0) {
679 			icmpv6_ndo_send(skb, ICMPV6_PARAMPROB,
680 					ICMPV6_HDR_FIELD, offset + 2);
681 			return -1;
682 		}
683 		*encap_limit = tel->encap_limit - 1;
684 	} else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) {
685 		*encap_limit = t->parms.encap_limit;
686 	}
687 
688 	memcpy(fl6, &t->fl.u.ip6, sizeof(*fl6));
689 
690 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
691 		*dsfield = ipv6_get_dsfield(ipv6h);
692 	else
693 		*dsfield = ip6_tclass(t->parms.flowinfo);
694 
695 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
696 		fl6->flowlabel |= ip6_flowlabel(ipv6h);
697 
698 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
699 		fl6->flowi6_mark = skb->mark;
700 	else
701 		fl6->flowi6_mark = t->parms.fwmark;
702 
703 	fl6->flowi6_uid = sock_net_uid(dev_net(dev), NULL);
704 
705 	return 0;
706 }
707 
708 static int prepare_ip6gre_xmit_other(struct sk_buff *skb,
709 				     struct net_device *dev,
710 				     struct flowi6 *fl6, __u8 *dsfield,
711 				     int *encap_limit)
712 {
713 	struct ip6_tnl *t = netdev_priv(dev);
714 
715 	if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
716 		*encap_limit = t->parms.encap_limit;
717 
718 	memcpy(fl6, &t->fl.u.ip6, sizeof(*fl6));
719 
720 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
721 		*dsfield = 0;
722 	else
723 		*dsfield = ip6_tclass(t->parms.flowinfo);
724 
725 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
726 		fl6->flowi6_mark = skb->mark;
727 	else
728 		fl6->flowi6_mark = t->parms.fwmark;
729 
730 	fl6->flowi6_uid = sock_net_uid(dev_net(dev), NULL);
731 
732 	return 0;
733 }
734 
735 static struct ip_tunnel_info *skb_tunnel_info_txcheck(struct sk_buff *skb)
736 {
737 	struct ip_tunnel_info *tun_info;
738 
739 	tun_info = skb_tunnel_info(skb);
740 	if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX)))
741 		return ERR_PTR(-EINVAL);
742 
743 	return tun_info;
744 }
745 
746 static netdev_tx_t __gre6_xmit(struct sk_buff *skb,
747 			       struct net_device *dev, __u8 dsfield,
748 			       struct flowi6 *fl6, int encap_limit,
749 			       __u32 *pmtu, __be16 proto)
750 {
751 	struct ip6_tnl *tunnel = netdev_priv(dev);
752 	IP_TUNNEL_DECLARE_FLAGS(flags);
753 	__be16 protocol;
754 
755 	if (dev->type == ARPHRD_ETHER)
756 		IPCB(skb)->flags = 0;
757 
758 	if (dev->header_ops && dev->type == ARPHRD_IP6GRE)
759 		fl6->daddr = ((struct ipv6hdr *)skb->data)->daddr;
760 	else
761 		fl6->daddr = tunnel->parms.raddr;
762 
763 	/* Push GRE header. */
764 	protocol = (dev->type == ARPHRD_ETHER) ? htons(ETH_P_TEB) : proto;
765 
766 	if (tunnel->parms.collect_md) {
767 		struct ip_tunnel_info *tun_info;
768 		const struct ip_tunnel_key *key;
769 		int tun_hlen;
770 
771 		tun_info = skb_tunnel_info_txcheck(skb);
772 		if (IS_ERR(tun_info) ||
773 		    unlikely(ip_tunnel_info_af(tun_info) != AF_INET6))
774 			return -EINVAL;
775 
776 		key = &tun_info->key;
777 		memset(fl6, 0, sizeof(*fl6));
778 		fl6->flowi6_proto = IPPROTO_GRE;
779 		fl6->daddr = key->u.ipv6.dst;
780 		fl6->flowlabel = key->label;
781 		fl6->flowi6_uid = sock_net_uid(dev_net(dev), NULL);
782 		fl6->fl6_gre_key = tunnel_id_to_key32(key->tun_id);
783 
784 		dsfield = key->tos;
785 		ip_tunnel_flags_zero(flags);
786 		__set_bit(IP_TUNNEL_CSUM_BIT, flags);
787 		__set_bit(IP_TUNNEL_KEY_BIT, flags);
788 		__set_bit(IP_TUNNEL_SEQ_BIT, flags);
789 		ip_tunnel_flags_and(flags, flags, key->tun_flags);
790 		tun_hlen = gre_calc_hlen(flags);
791 
792 		if (skb_cow_head(skb, dev->needed_headroom ?: tun_hlen + tunnel->encap_hlen))
793 			return -ENOMEM;
794 
795 		gre_build_header(skb, tun_hlen,
796 				 flags, protocol,
797 				 tunnel_id_to_key32(tun_info->key.tun_id),
798 				 test_bit(IP_TUNNEL_SEQ_BIT, flags) ?
799 				 htonl(atomic_fetch_inc(&tunnel->o_seqno)) :
800 				 0);
801 
802 	} else {
803 		if (skb_cow_head(skb, dev->needed_headroom ?: tunnel->hlen))
804 			return -ENOMEM;
805 
806 		ip_tunnel_flags_copy(flags, tunnel->parms.o_flags);
807 
808 		gre_build_header(skb, tunnel->tun_hlen, flags,
809 				 protocol, tunnel->parms.o_key,
810 				 test_bit(IP_TUNNEL_SEQ_BIT, flags) ?
811 				 htonl(atomic_fetch_inc(&tunnel->o_seqno)) :
812 				 0);
813 	}
814 
815 	return ip6_tnl_xmit(skb, dev, dsfield, fl6, encap_limit, pmtu,
816 			    NEXTHDR_GRE);
817 }
818 
819 static inline int ip6gre_xmit_ipv4(struct sk_buff *skb, struct net_device *dev)
820 {
821 	struct ip6_tnl *t = netdev_priv(dev);
822 	int encap_limit = -1;
823 	struct flowi6 fl6;
824 	__u8 dsfield = 0;
825 	__u32 mtu;
826 	int err;
827 
828 	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
829 
830 	if (!t->parms.collect_md)
831 		prepare_ip6gre_xmit_ipv4(skb, dev, &fl6,
832 					 &dsfield, &encap_limit);
833 
834 	err = gre_handle_offloads(skb, test_bit(IP_TUNNEL_CSUM_BIT,
835 						t->parms.o_flags));
836 	if (err)
837 		return -1;
838 
839 	err = __gre6_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
840 			  skb->protocol);
841 	if (err != 0) {
842 		/* XXX: send ICMP error even if DF is not set. */
843 		if (err == -EMSGSIZE)
844 			icmp_ndo_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
845 				      htonl(mtu));
846 		return -1;
847 	}
848 
849 	return 0;
850 }
851 
852 static inline int ip6gre_xmit_ipv6(struct sk_buff *skb, struct net_device *dev)
853 {
854 	struct ip6_tnl *t = netdev_priv(dev);
855 	struct ipv6hdr *ipv6h = ipv6_hdr(skb);
856 	int encap_limit = -1;
857 	struct flowi6 fl6;
858 	__u8 dsfield = 0;
859 	__u32 mtu;
860 	int err;
861 
862 	if (ipv6_addr_equal(&t->parms.raddr, &ipv6h->saddr))
863 		return -1;
864 
865 	if (!t->parms.collect_md &&
866 	    prepare_ip6gre_xmit_ipv6(skb, dev, &fl6, &dsfield, &encap_limit))
867 		return -1;
868 
869 	if (gre_handle_offloads(skb, test_bit(IP_TUNNEL_CSUM_BIT,
870 					      t->parms.o_flags)))
871 		return -1;
872 
873 	err = __gre6_xmit(skb, dev, dsfield, &fl6, encap_limit,
874 			  &mtu, skb->protocol);
875 	if (err != 0) {
876 		if (err == -EMSGSIZE)
877 			icmpv6_ndo_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
878 		return -1;
879 	}
880 
881 	return 0;
882 }
883 
884 static int ip6gre_xmit_other(struct sk_buff *skb, struct net_device *dev)
885 {
886 	struct ip6_tnl *t = netdev_priv(dev);
887 	int encap_limit = -1;
888 	struct flowi6 fl6;
889 	__u8 dsfield = 0;
890 	__u32 mtu;
891 	int err;
892 
893 	if (!t->parms.collect_md &&
894 	    prepare_ip6gre_xmit_other(skb, dev, &fl6, &dsfield, &encap_limit))
895 		return -1;
896 
897 	err = gre_handle_offloads(skb, test_bit(IP_TUNNEL_CSUM_BIT,
898 						t->parms.o_flags));
899 	if (err)
900 		return err;
901 	err = __gre6_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu, skb->protocol);
902 
903 	return err;
904 }
905 
906 static netdev_tx_t ip6gre_tunnel_xmit(struct sk_buff *skb,
907 	struct net_device *dev)
908 {
909 	struct ip6_tnl *t = netdev_priv(dev);
910 	__be16 payload_protocol;
911 	int ret;
912 
913 	if (!pskb_inet_may_pull(skb))
914 		goto tx_err;
915 
916 	if (!ip6_tnl_xmit_ctl(t, &t->parms.laddr, &t->parms.raddr))
917 		goto tx_err;
918 
919 	payload_protocol = skb_protocol(skb, true);
920 	switch (payload_protocol) {
921 	case htons(ETH_P_IP):
922 		ret = ip6gre_xmit_ipv4(skb, dev);
923 		break;
924 	case htons(ETH_P_IPV6):
925 		ret = ip6gre_xmit_ipv6(skb, dev);
926 		break;
927 	default:
928 		ret = ip6gre_xmit_other(skb, dev);
929 		break;
930 	}
931 
932 	if (ret < 0)
933 		goto tx_err;
934 
935 	return NETDEV_TX_OK;
936 
937 tx_err:
938 	if (!t->parms.collect_md || !IS_ERR(skb_tunnel_info_txcheck(skb)))
939 		DEV_STATS_INC(dev, tx_errors);
940 	DEV_STATS_INC(dev, tx_dropped);
941 	kfree_skb(skb);
942 	return NETDEV_TX_OK;
943 }
944 
945 static netdev_tx_t ip6erspan_tunnel_xmit(struct sk_buff *skb,
946 					 struct net_device *dev)
947 {
948 	struct ip_tunnel_info *tun_info = NULL;
949 	struct ip6_tnl *t = netdev_priv(dev);
950 	struct dst_entry *dst = skb_dst(skb);
951 	IP_TUNNEL_DECLARE_FLAGS(flags) = { };
952 	bool truncate = false;
953 	int encap_limit = -1;
954 	__u8 dsfield = false;
955 	struct flowi6 fl6;
956 	int err = -EINVAL;
957 	__be16 proto;
958 	__u32 mtu;
959 	int nhoff;
960 
961 	if (!pskb_inet_may_pull(skb))
962 		goto tx_err;
963 
964 	if (!ip6_tnl_xmit_ctl(t, &t->parms.laddr, &t->parms.raddr))
965 		goto tx_err;
966 
967 	if (gre_handle_offloads(skb, false))
968 		goto tx_err;
969 
970 	if (skb->len > dev->mtu + dev->hard_header_len) {
971 		if (pskb_trim(skb, dev->mtu + dev->hard_header_len))
972 			goto tx_err;
973 		truncate = true;
974 	}
975 
976 	nhoff = skb_network_offset(skb);
977 	if (skb->protocol == htons(ETH_P_IP) &&
978 	    (ntohs(ip_hdr(skb)->tot_len) > skb->len - nhoff))
979 		truncate = true;
980 
981 	if (skb->protocol == htons(ETH_P_IPV6)) {
982 		int thoff;
983 
984 		if (skb_transport_header_was_set(skb))
985 			thoff = skb_transport_offset(skb);
986 		else
987 			thoff = nhoff + sizeof(struct ipv6hdr);
988 		if (ntohs(ipv6_hdr(skb)->payload_len) > skb->len - thoff)
989 			truncate = true;
990 	}
991 
992 	if (skb_cow_head(skb, dev->needed_headroom ?: t->hlen))
993 		goto tx_err;
994 
995 	__clear_bit(IP_TUNNEL_KEY_BIT, t->parms.o_flags);
996 	IPCB(skb)->flags = 0;
997 
998 	/* For collect_md mode, derive fl6 from the tunnel key,
999 	 * for native mode, call prepare_ip6gre_xmit_{ipv4,ipv6}.
1000 	 */
1001 	if (t->parms.collect_md) {
1002 		const struct ip_tunnel_key *key;
1003 		struct erspan_metadata *md;
1004 		__be32 tun_id;
1005 
1006 		tun_info = skb_tunnel_info_txcheck(skb);
1007 		if (IS_ERR(tun_info) ||
1008 		    unlikely(ip_tunnel_info_af(tun_info) != AF_INET6))
1009 			goto tx_err;
1010 
1011 		key = &tun_info->key;
1012 		memset(&fl6, 0, sizeof(fl6));
1013 		fl6.flowi6_proto = IPPROTO_GRE;
1014 		fl6.daddr = key->u.ipv6.dst;
1015 		fl6.flowlabel = key->label;
1016 		fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
1017 		fl6.fl6_gre_key = tunnel_id_to_key32(key->tun_id);
1018 
1019 		dsfield = key->tos;
1020 		if (!test_bit(IP_TUNNEL_ERSPAN_OPT_BIT,
1021 			      tun_info->key.tun_flags))
1022 			goto tx_err;
1023 		if (tun_info->options_len < sizeof(*md))
1024 			goto tx_err;
1025 		md = ip_tunnel_info_opts(tun_info);
1026 
1027 		tun_id = tunnel_id_to_key32(key->tun_id);
1028 		if (md->version == 1) {
1029 			erspan_build_header(skb,
1030 					    ntohl(tun_id),
1031 					    ntohl(md->u.index), truncate,
1032 					    false);
1033 			proto = htons(ETH_P_ERSPAN);
1034 		} else if (md->version == 2) {
1035 			erspan_build_header_v2(skb,
1036 					       ntohl(tun_id),
1037 					       md->u.md2.dir,
1038 					       get_hwid(&md->u.md2),
1039 					       truncate, false);
1040 			proto = htons(ETH_P_ERSPAN2);
1041 		} else {
1042 			goto tx_err;
1043 		}
1044 	} else {
1045 		switch (skb->protocol) {
1046 		case htons(ETH_P_IP):
1047 			memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1048 			prepare_ip6gre_xmit_ipv4(skb, dev, &fl6,
1049 						 &dsfield, &encap_limit);
1050 			break;
1051 		case htons(ETH_P_IPV6):
1052 			if (ipv6_addr_equal(&t->parms.raddr, &ipv6_hdr(skb)->saddr))
1053 				goto tx_err;
1054 			if (prepare_ip6gre_xmit_ipv6(skb, dev, &fl6,
1055 						     &dsfield, &encap_limit))
1056 				goto tx_err;
1057 			break;
1058 		default:
1059 			memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
1060 			break;
1061 		}
1062 
1063 		if (t->parms.erspan_ver == 1) {
1064 			erspan_build_header(skb, ntohl(t->parms.o_key),
1065 					    t->parms.index,
1066 					    truncate, false);
1067 			proto = htons(ETH_P_ERSPAN);
1068 		} else if (t->parms.erspan_ver == 2) {
1069 			erspan_build_header_v2(skb, ntohl(t->parms.o_key),
1070 					       t->parms.dir,
1071 					       t->parms.hwid,
1072 					       truncate, false);
1073 			proto = htons(ETH_P_ERSPAN2);
1074 		} else {
1075 			goto tx_err;
1076 		}
1077 
1078 		fl6.daddr = t->parms.raddr;
1079 	}
1080 
1081 	/* Push GRE header. */
1082 	__set_bit(IP_TUNNEL_SEQ_BIT, flags);
1083 	gre_build_header(skb, 8, flags, proto, 0,
1084 			 htonl(atomic_fetch_inc(&t->o_seqno)));
1085 
1086 	/* TooBig packet may have updated dst->dev's mtu */
1087 	if (!t->parms.collect_md && dst && dst_mtu(dst) > dst->dev->mtu)
1088 		dst->ops->update_pmtu(dst, NULL, skb, dst->dev->mtu, false);
1089 
1090 	err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
1091 			   NEXTHDR_GRE);
1092 	if (err != 0) {
1093 		/* XXX: send ICMP error even if DF is not set. */
1094 		if (err == -EMSGSIZE) {
1095 			if (skb->protocol == htons(ETH_P_IP))
1096 				icmp_ndo_send(skb, ICMP_DEST_UNREACH,
1097 					      ICMP_FRAG_NEEDED, htonl(mtu));
1098 			else
1099 				icmpv6_ndo_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
1100 		}
1101 
1102 		goto tx_err;
1103 	}
1104 	return NETDEV_TX_OK;
1105 
1106 tx_err:
1107 	if (!IS_ERR(tun_info))
1108 		DEV_STATS_INC(dev, tx_errors);
1109 	DEV_STATS_INC(dev, tx_dropped);
1110 	kfree_skb(skb);
1111 	return NETDEV_TX_OK;
1112 }
1113 
1114 static void ip6gre_tnl_link_config_common(struct ip6_tnl *t)
1115 {
1116 	struct net_device *dev = t->dev;
1117 	struct __ip6_tnl_parm *p = &t->parms;
1118 	struct flowi6 *fl6 = &t->fl.u.ip6;
1119 
1120 	if (dev->type != ARPHRD_ETHER) {
1121 		__dev_addr_set(dev, &p->laddr, sizeof(struct in6_addr));
1122 		memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
1123 	}
1124 
1125 	/* Set up flowi template */
1126 	fl6->saddr = p->laddr;
1127 	fl6->daddr = p->raddr;
1128 	fl6->flowi6_oif = p->link;
1129 	fl6->flowlabel = 0;
1130 	fl6->flowi6_proto = IPPROTO_GRE;
1131 	fl6->fl6_gre_key = t->parms.o_key;
1132 
1133 	if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
1134 		fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
1135 	if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
1136 		fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
1137 
1138 	p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
1139 	p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
1140 
1141 	if (p->flags&IP6_TNL_F_CAP_XMIT &&
1142 			p->flags&IP6_TNL_F_CAP_RCV && dev->type != ARPHRD_ETHER)
1143 		dev->flags |= IFF_POINTOPOINT;
1144 	else
1145 		dev->flags &= ~IFF_POINTOPOINT;
1146 }
1147 
1148 static void ip6gre_tnl_link_config_route(struct ip6_tnl *t, int set_mtu,
1149 					 int t_hlen)
1150 {
1151 	const struct __ip6_tnl_parm *p = &t->parms;
1152 	struct net_device *dev = t->dev;
1153 
1154 	if (p->flags & IP6_TNL_F_CAP_XMIT) {
1155 		int strict = (ipv6_addr_type(&p->raddr) &
1156 			      (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
1157 
1158 		struct rt6_info *rt = rt6_lookup(t->net,
1159 						 &p->raddr, &p->laddr,
1160 						 p->link, NULL, strict);
1161 
1162 		if (!rt)
1163 			return;
1164 
1165 		if (rt->dst.dev) {
1166 			unsigned short dst_len = rt->dst.dev->hard_header_len +
1167 						 t_hlen;
1168 
1169 			if (t->dev->header_ops)
1170 				dev->hard_header_len = dst_len;
1171 			else
1172 				dev->needed_headroom = dst_len;
1173 
1174 			if (set_mtu) {
1175 				int mtu = rt->dst.dev->mtu - t_hlen;
1176 
1177 				if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1178 					mtu -= 8;
1179 				if (dev->type == ARPHRD_ETHER)
1180 					mtu -= ETH_HLEN;
1181 
1182 				if (mtu < IPV6_MIN_MTU)
1183 					mtu = IPV6_MIN_MTU;
1184 				WRITE_ONCE(dev->mtu, mtu);
1185 			}
1186 		}
1187 		ip6_rt_put(rt);
1188 	}
1189 }
1190 
1191 static int ip6gre_calc_hlen(struct ip6_tnl *tunnel)
1192 {
1193 	int t_hlen;
1194 
1195 	tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags);
1196 	tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen;
1197 
1198 	t_hlen = tunnel->hlen + sizeof(struct ipv6hdr);
1199 
1200 	if (tunnel->dev->header_ops)
1201 		tunnel->dev->hard_header_len = LL_MAX_HEADER + t_hlen;
1202 	else
1203 		tunnel->dev->needed_headroom = LL_MAX_HEADER + t_hlen;
1204 
1205 	return t_hlen;
1206 }
1207 
1208 static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu)
1209 {
1210 	ip6gre_tnl_link_config_common(t);
1211 	ip6gre_tnl_link_config_route(t, set_mtu, ip6gre_calc_hlen(t));
1212 }
1213 
1214 static void ip6gre_tnl_copy_tnl_parm(struct ip6_tnl *t,
1215 				     const struct __ip6_tnl_parm *p)
1216 {
1217 	t->parms.laddr = p->laddr;
1218 	t->parms.raddr = p->raddr;
1219 	t->parms.flags = p->flags;
1220 	t->parms.hop_limit = p->hop_limit;
1221 	t->parms.encap_limit = p->encap_limit;
1222 	t->parms.flowinfo = p->flowinfo;
1223 	t->parms.link = p->link;
1224 	t->parms.proto = p->proto;
1225 	t->parms.i_key = p->i_key;
1226 	t->parms.o_key = p->o_key;
1227 	ip_tunnel_flags_copy(t->parms.i_flags, p->i_flags);
1228 	ip_tunnel_flags_copy(t->parms.o_flags, p->o_flags);
1229 	t->parms.fwmark = p->fwmark;
1230 	t->parms.erspan_ver = p->erspan_ver;
1231 	t->parms.index = p->index;
1232 	t->parms.dir = p->dir;
1233 	t->parms.hwid = p->hwid;
1234 	dst_cache_reset(&t->dst_cache);
1235 }
1236 
1237 static int ip6gre_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p,
1238 			     int set_mtu)
1239 {
1240 	ip6gre_tnl_copy_tnl_parm(t, p);
1241 	ip6gre_tnl_link_config(t, set_mtu);
1242 	return 0;
1243 }
1244 
1245 static void ip6gre_tnl_parm_from_user(struct __ip6_tnl_parm *p,
1246 	const struct ip6_tnl_parm2 *u)
1247 {
1248 	p->laddr = u->laddr;
1249 	p->raddr = u->raddr;
1250 	p->flags = u->flags;
1251 	p->hop_limit = u->hop_limit;
1252 	p->encap_limit = u->encap_limit;
1253 	p->flowinfo = u->flowinfo;
1254 	p->link = u->link;
1255 	p->i_key = u->i_key;
1256 	p->o_key = u->o_key;
1257 	gre_flags_to_tnl_flags(p->i_flags, u->i_flags);
1258 	gre_flags_to_tnl_flags(p->o_flags, u->o_flags);
1259 	memcpy(p->name, u->name, sizeof(u->name));
1260 }
1261 
1262 static void ip6gre_tnl_parm_to_user(struct ip6_tnl_parm2 *u,
1263 	const struct __ip6_tnl_parm *p)
1264 {
1265 	u->proto = IPPROTO_GRE;
1266 	u->laddr = p->laddr;
1267 	u->raddr = p->raddr;
1268 	u->flags = p->flags;
1269 	u->hop_limit = p->hop_limit;
1270 	u->encap_limit = p->encap_limit;
1271 	u->flowinfo = p->flowinfo;
1272 	u->link = p->link;
1273 	u->i_key = p->i_key;
1274 	u->o_key = p->o_key;
1275 	u->i_flags = gre_tnl_flags_to_gre_flags(p->i_flags);
1276 	u->o_flags = gre_tnl_flags_to_gre_flags(p->o_flags);
1277 	memcpy(u->name, p->name, sizeof(u->name));
1278 }
1279 
1280 static int ip6gre_tunnel_siocdevprivate(struct net_device *dev,
1281 					struct ifreq *ifr, void __user *data,
1282 					int cmd)
1283 {
1284 	int err = 0;
1285 	struct ip6_tnl_parm2 p;
1286 	struct __ip6_tnl_parm p1;
1287 	struct ip6_tnl *t = netdev_priv(dev);
1288 	struct net *net = t->net;
1289 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1290 
1291 	memset(&p1, 0, sizeof(p1));
1292 
1293 	switch (cmd) {
1294 	case SIOCGETTUNNEL:
1295 		if (dev == ign->fb_tunnel_dev) {
1296 			if (copy_from_user(&p, data, sizeof(p))) {
1297 				err = -EFAULT;
1298 				break;
1299 			}
1300 			ip6gre_tnl_parm_from_user(&p1, &p);
1301 			t = ip6gre_tunnel_locate(net, &p1, 0);
1302 			if (!t)
1303 				t = netdev_priv(dev);
1304 		}
1305 		memset(&p, 0, sizeof(p));
1306 		ip6gre_tnl_parm_to_user(&p, &t->parms);
1307 		if (copy_to_user(data, &p, sizeof(p)))
1308 			err = -EFAULT;
1309 		break;
1310 
1311 	case SIOCADDTUNNEL:
1312 	case SIOCCHGTUNNEL:
1313 		err = -EPERM;
1314 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1315 			goto done;
1316 
1317 		err = -EFAULT;
1318 		if (copy_from_user(&p, data, sizeof(p)))
1319 			goto done;
1320 
1321 		err = -EINVAL;
1322 		if ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING))
1323 			goto done;
1324 
1325 		if (!(p.i_flags&GRE_KEY))
1326 			p.i_key = 0;
1327 		if (!(p.o_flags&GRE_KEY))
1328 			p.o_key = 0;
1329 
1330 		ip6gre_tnl_parm_from_user(&p1, &p);
1331 		t = ip6gre_tunnel_locate(net, &p1, cmd == SIOCADDTUNNEL);
1332 
1333 		if (dev != ign->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
1334 			if (t) {
1335 				if (t->dev != dev) {
1336 					err = -EEXIST;
1337 					break;
1338 				}
1339 			} else {
1340 				t = netdev_priv(dev);
1341 
1342 				ip6gre_tunnel_unlink(ign, t);
1343 				synchronize_net();
1344 				ip6gre_tnl_change(t, &p1, 1);
1345 				ip6gre_tunnel_link(ign, t);
1346 				netdev_state_change(dev);
1347 			}
1348 		}
1349 
1350 		if (t) {
1351 			err = 0;
1352 
1353 			memset(&p, 0, sizeof(p));
1354 			ip6gre_tnl_parm_to_user(&p, &t->parms);
1355 			if (copy_to_user(data, &p, sizeof(p)))
1356 				err = -EFAULT;
1357 		} else
1358 			err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1359 		break;
1360 
1361 	case SIOCDELTUNNEL:
1362 		err = -EPERM;
1363 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1364 			goto done;
1365 
1366 		if (dev == ign->fb_tunnel_dev) {
1367 			err = -EFAULT;
1368 			if (copy_from_user(&p, data, sizeof(p)))
1369 				goto done;
1370 			err = -ENOENT;
1371 			ip6gre_tnl_parm_from_user(&p1, &p);
1372 			t = ip6gre_tunnel_locate(net, &p1, 0);
1373 			if (!t)
1374 				goto done;
1375 			err = -EPERM;
1376 			if (t == netdev_priv(ign->fb_tunnel_dev))
1377 				goto done;
1378 			dev = t->dev;
1379 		}
1380 		unregister_netdevice(dev);
1381 		err = 0;
1382 		break;
1383 
1384 	default:
1385 		err = -EINVAL;
1386 	}
1387 
1388 done:
1389 	return err;
1390 }
1391 
1392 static int ip6gre_header(struct sk_buff *skb, struct net_device *dev,
1393 			 unsigned short type, const void *daddr,
1394 			 const void *saddr, unsigned int len)
1395 {
1396 	struct ip6_tnl *t = netdev_priv(dev);
1397 	struct ipv6hdr *ipv6h;
1398 	__be16 *p;
1399 
1400 	ipv6h = skb_push(skb, t->hlen + sizeof(*ipv6h));
1401 	ip6_flow_hdr(ipv6h, 0, ip6_make_flowlabel(dev_net(dev), skb,
1402 						  t->fl.u.ip6.flowlabel,
1403 						  true, &t->fl.u.ip6));
1404 	ipv6h->hop_limit = t->parms.hop_limit;
1405 	ipv6h->nexthdr = NEXTHDR_GRE;
1406 	ipv6h->saddr = t->parms.laddr;
1407 	ipv6h->daddr = t->parms.raddr;
1408 
1409 	p = (__be16 *)(ipv6h + 1);
1410 	p[0] = ip_tunnel_flags_to_be16(t->parms.o_flags);
1411 	p[1] = htons(type);
1412 
1413 	/*
1414 	 *	Set the source hardware address.
1415 	 */
1416 
1417 	if (saddr)
1418 		memcpy(&ipv6h->saddr, saddr, sizeof(struct in6_addr));
1419 	if (daddr)
1420 		memcpy(&ipv6h->daddr, daddr, sizeof(struct in6_addr));
1421 	if (!ipv6_addr_any(&ipv6h->daddr))
1422 		return t->hlen;
1423 
1424 	return -t->hlen;
1425 }
1426 
1427 static const struct header_ops ip6gre_header_ops = {
1428 	.create	= ip6gre_header,
1429 };
1430 
1431 static const struct net_device_ops ip6gre_netdev_ops = {
1432 	.ndo_init		= ip6gre_tunnel_init,
1433 	.ndo_uninit		= ip6gre_tunnel_uninit,
1434 	.ndo_start_xmit		= ip6gre_tunnel_xmit,
1435 	.ndo_siocdevprivate	= ip6gre_tunnel_siocdevprivate,
1436 	.ndo_change_mtu		= ip6_tnl_change_mtu,
1437 	.ndo_get_iflink		= ip6_tnl_get_iflink,
1438 };
1439 
1440 static void ip6gre_dev_free(struct net_device *dev)
1441 {
1442 	struct ip6_tnl *t = netdev_priv(dev);
1443 
1444 	gro_cells_destroy(&t->gro_cells);
1445 	dst_cache_destroy(&t->dst_cache);
1446 }
1447 
1448 static void ip6gre_tunnel_setup(struct net_device *dev)
1449 {
1450 	dev->netdev_ops = &ip6gre_netdev_ops;
1451 	dev->needs_free_netdev = true;
1452 	dev->priv_destructor = ip6gre_dev_free;
1453 
1454 	dev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS;
1455 	dev->type = ARPHRD_IP6GRE;
1456 
1457 	dev->flags |= IFF_NOARP;
1458 	dev->addr_len = sizeof(struct in6_addr);
1459 	netif_keep_dst(dev);
1460 	/* This perm addr will be used as interface identifier by IPv6 */
1461 	dev->addr_assign_type = NET_ADDR_RANDOM;
1462 	eth_random_addr(dev->perm_addr);
1463 }
1464 
1465 #define GRE6_FEATURES (NETIF_F_SG |		\
1466 		       NETIF_F_FRAGLIST |	\
1467 		       NETIF_F_HIGHDMA |	\
1468 		       NETIF_F_HW_CSUM)
1469 
1470 static void ip6gre_tnl_init_features(struct net_device *dev)
1471 {
1472 	struct ip6_tnl *nt = netdev_priv(dev);
1473 
1474 	dev->features		|= GRE6_FEATURES | NETIF_F_LLTX;
1475 	dev->hw_features	|= GRE6_FEATURES;
1476 
1477 	/* TCP offload with GRE SEQ is not supported, nor can we support 2
1478 	 * levels of outer headers requiring an update.
1479 	 */
1480 	if (test_bit(IP_TUNNEL_SEQ_BIT, nt->parms.o_flags))
1481 		return;
1482 	if (test_bit(IP_TUNNEL_CSUM_BIT, nt->parms.o_flags) &&
1483 	    nt->encap.type != TUNNEL_ENCAP_NONE)
1484 		return;
1485 
1486 	dev->features |= NETIF_F_GSO_SOFTWARE;
1487 	dev->hw_features |= NETIF_F_GSO_SOFTWARE;
1488 }
1489 
1490 static int ip6gre_tunnel_init_common(struct net_device *dev)
1491 {
1492 	struct ip6_tnl *tunnel;
1493 	int ret;
1494 	int t_hlen;
1495 
1496 	tunnel = netdev_priv(dev);
1497 
1498 	tunnel->dev = dev;
1499 	tunnel->net = dev_net(dev);
1500 	strcpy(tunnel->parms.name, dev->name);
1501 
1502 	ret = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL);
1503 	if (ret)
1504 		return ret;
1505 
1506 	ret = gro_cells_init(&tunnel->gro_cells, dev);
1507 	if (ret)
1508 		goto cleanup_dst_cache_init;
1509 
1510 	t_hlen = ip6gre_calc_hlen(tunnel);
1511 	dev->mtu = ETH_DATA_LEN - t_hlen;
1512 	if (dev->type == ARPHRD_ETHER)
1513 		dev->mtu -= ETH_HLEN;
1514 	if (!(tunnel->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1515 		dev->mtu -= 8;
1516 
1517 	if (tunnel->parms.collect_md) {
1518 		netif_keep_dst(dev);
1519 	}
1520 	ip6gre_tnl_init_features(dev);
1521 
1522 	netdev_hold(dev, &tunnel->dev_tracker, GFP_KERNEL);
1523 	netdev_lockdep_set_classes(dev);
1524 	return 0;
1525 
1526 cleanup_dst_cache_init:
1527 	dst_cache_destroy(&tunnel->dst_cache);
1528 	return ret;
1529 }
1530 
1531 static int ip6gre_tunnel_init(struct net_device *dev)
1532 {
1533 	struct ip6_tnl *tunnel;
1534 	int ret;
1535 
1536 	ret = ip6gre_tunnel_init_common(dev);
1537 	if (ret)
1538 		return ret;
1539 
1540 	tunnel = netdev_priv(dev);
1541 
1542 	if (tunnel->parms.collect_md)
1543 		return 0;
1544 
1545 	__dev_addr_set(dev, &tunnel->parms.laddr, sizeof(struct in6_addr));
1546 	memcpy(dev->broadcast, &tunnel->parms.raddr, sizeof(struct in6_addr));
1547 
1548 	if (ipv6_addr_any(&tunnel->parms.raddr))
1549 		dev->header_ops = &ip6gre_header_ops;
1550 
1551 	return 0;
1552 }
1553 
1554 static void ip6gre_fb_tunnel_init(struct net_device *dev)
1555 {
1556 	struct ip6_tnl *tunnel = netdev_priv(dev);
1557 
1558 	tunnel->dev = dev;
1559 	tunnel->net = dev_net(dev);
1560 	strcpy(tunnel->parms.name, dev->name);
1561 
1562 	tunnel->hlen		= sizeof(struct ipv6hdr) + 4;
1563 }
1564 
1565 static struct inet6_protocol ip6gre_protocol __read_mostly = {
1566 	.handler     = gre_rcv,
1567 	.err_handler = ip6gre_err,
1568 	.flags       = INET6_PROTO_FINAL,
1569 };
1570 
1571 static void ip6gre_destroy_tunnels(struct net *net, struct list_head *head)
1572 {
1573 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1574 	struct net_device *dev, *aux;
1575 	int prio;
1576 
1577 	for_each_netdev_safe(net, dev, aux)
1578 		if (dev->rtnl_link_ops == &ip6gre_link_ops ||
1579 		    dev->rtnl_link_ops == &ip6gre_tap_ops ||
1580 		    dev->rtnl_link_ops == &ip6erspan_tap_ops)
1581 			unregister_netdevice_queue(dev, head);
1582 
1583 	for (prio = 0; prio < 4; prio++) {
1584 		int h;
1585 		for (h = 0; h < IP6_GRE_HASH_SIZE; h++) {
1586 			struct ip6_tnl *t;
1587 
1588 			t = rtnl_dereference(ign->tunnels[prio][h]);
1589 
1590 			while (t) {
1591 				/* If dev is in the same netns, it has already
1592 				 * been added to the list by the previous loop.
1593 				 */
1594 				if (!net_eq(dev_net(t->dev), net))
1595 					unregister_netdevice_queue(t->dev,
1596 								   head);
1597 				t = rtnl_dereference(t->next);
1598 			}
1599 		}
1600 	}
1601 }
1602 
1603 static int __net_init ip6gre_init_net(struct net *net)
1604 {
1605 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1606 	struct net_device *ndev;
1607 	int err;
1608 
1609 	if (!net_has_fallback_tunnels(net))
1610 		return 0;
1611 	ndev = alloc_netdev(sizeof(struct ip6_tnl), "ip6gre0",
1612 			    NET_NAME_UNKNOWN, ip6gre_tunnel_setup);
1613 	if (!ndev) {
1614 		err = -ENOMEM;
1615 		goto err_alloc_dev;
1616 	}
1617 	ign->fb_tunnel_dev = ndev;
1618 	dev_net_set(ign->fb_tunnel_dev, net);
1619 	/* FB netdevice is special: we have one, and only one per netns.
1620 	 * Allowing to move it to another netns is clearly unsafe.
1621 	 */
1622 	ign->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
1623 
1624 
1625 	ip6gre_fb_tunnel_init(ign->fb_tunnel_dev);
1626 	ign->fb_tunnel_dev->rtnl_link_ops = &ip6gre_link_ops;
1627 
1628 	err = register_netdev(ign->fb_tunnel_dev);
1629 	if (err)
1630 		goto err_reg_dev;
1631 
1632 	rcu_assign_pointer(ign->tunnels_wc[0],
1633 			   netdev_priv(ign->fb_tunnel_dev));
1634 	return 0;
1635 
1636 err_reg_dev:
1637 	free_netdev(ndev);
1638 err_alloc_dev:
1639 	return err;
1640 }
1641 
1642 static void __net_exit ip6gre_exit_batch_rtnl(struct list_head *net_list,
1643 					      struct list_head *dev_to_kill)
1644 {
1645 	struct net *net;
1646 
1647 	ASSERT_RTNL();
1648 	list_for_each_entry(net, net_list, exit_list)
1649 		ip6gre_destroy_tunnels(net, dev_to_kill);
1650 }
1651 
1652 static struct pernet_operations ip6gre_net_ops = {
1653 	.init = ip6gre_init_net,
1654 	.exit_batch_rtnl = ip6gre_exit_batch_rtnl,
1655 	.id   = &ip6gre_net_id,
1656 	.size = sizeof(struct ip6gre_net),
1657 };
1658 
1659 static int ip6gre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[],
1660 				  struct netlink_ext_ack *extack)
1661 {
1662 	__be16 flags;
1663 
1664 	if (!data)
1665 		return 0;
1666 
1667 	flags = 0;
1668 	if (data[IFLA_GRE_IFLAGS])
1669 		flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1670 	if (data[IFLA_GRE_OFLAGS])
1671 		flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1672 	if (flags & (GRE_VERSION|GRE_ROUTING))
1673 		return -EINVAL;
1674 
1675 	return 0;
1676 }
1677 
1678 static int ip6gre_tap_validate(struct nlattr *tb[], struct nlattr *data[],
1679 			       struct netlink_ext_ack *extack)
1680 {
1681 	struct in6_addr daddr;
1682 
1683 	if (tb[IFLA_ADDRESS]) {
1684 		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1685 			return -EINVAL;
1686 		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1687 			return -EADDRNOTAVAIL;
1688 	}
1689 
1690 	if (!data)
1691 		goto out;
1692 
1693 	if (data[IFLA_GRE_REMOTE]) {
1694 		daddr = nla_get_in6_addr(data[IFLA_GRE_REMOTE]);
1695 		if (ipv6_addr_any(&daddr))
1696 			return -EINVAL;
1697 	}
1698 
1699 out:
1700 	return ip6gre_tunnel_validate(tb, data, extack);
1701 }
1702 
1703 static int ip6erspan_tap_validate(struct nlattr *tb[], struct nlattr *data[],
1704 				  struct netlink_ext_ack *extack)
1705 {
1706 	__be16 flags = 0;
1707 	int ret, ver = 0;
1708 
1709 	if (!data)
1710 		return 0;
1711 
1712 	ret = ip6gre_tap_validate(tb, data, extack);
1713 	if (ret)
1714 		return ret;
1715 
1716 	/* ERSPAN should only have GRE sequence and key flag */
1717 	if (data[IFLA_GRE_OFLAGS])
1718 		flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1719 	if (data[IFLA_GRE_IFLAGS])
1720 		flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1721 	if (!data[IFLA_GRE_COLLECT_METADATA] &&
1722 	    flags != (GRE_SEQ | GRE_KEY))
1723 		return -EINVAL;
1724 
1725 	/* ERSPAN Session ID only has 10-bit. Since we reuse
1726 	 * 32-bit key field as ID, check it's range.
1727 	 */
1728 	if (data[IFLA_GRE_IKEY] &&
1729 	    (ntohl(nla_get_be32(data[IFLA_GRE_IKEY])) & ~ID_MASK))
1730 		return -EINVAL;
1731 
1732 	if (data[IFLA_GRE_OKEY] &&
1733 	    (ntohl(nla_get_be32(data[IFLA_GRE_OKEY])) & ~ID_MASK))
1734 		return -EINVAL;
1735 
1736 	if (data[IFLA_GRE_ERSPAN_VER]) {
1737 		ver = nla_get_u8(data[IFLA_GRE_ERSPAN_VER]);
1738 		if (ver != 1 && ver != 2)
1739 			return -EINVAL;
1740 	}
1741 
1742 	if (ver == 1) {
1743 		if (data[IFLA_GRE_ERSPAN_INDEX]) {
1744 			u32 index = nla_get_u32(data[IFLA_GRE_ERSPAN_INDEX]);
1745 
1746 			if (index & ~INDEX_MASK)
1747 				return -EINVAL;
1748 		}
1749 	} else if (ver == 2) {
1750 		if (data[IFLA_GRE_ERSPAN_DIR]) {
1751 			u16 dir = nla_get_u8(data[IFLA_GRE_ERSPAN_DIR]);
1752 
1753 			if (dir & ~(DIR_MASK >> DIR_OFFSET))
1754 				return -EINVAL;
1755 		}
1756 
1757 		if (data[IFLA_GRE_ERSPAN_HWID]) {
1758 			u16 hwid = nla_get_u16(data[IFLA_GRE_ERSPAN_HWID]);
1759 
1760 			if (hwid & ~(HWID_MASK >> HWID_OFFSET))
1761 				return -EINVAL;
1762 		}
1763 	}
1764 
1765 	return 0;
1766 }
1767 
1768 static void ip6erspan_set_version(struct nlattr *data[],
1769 				  struct __ip6_tnl_parm *parms)
1770 {
1771 	if (!data)
1772 		return;
1773 
1774 	parms->erspan_ver = 1;
1775 	if (data[IFLA_GRE_ERSPAN_VER])
1776 		parms->erspan_ver = nla_get_u8(data[IFLA_GRE_ERSPAN_VER]);
1777 
1778 	if (parms->erspan_ver == 1) {
1779 		if (data[IFLA_GRE_ERSPAN_INDEX])
1780 			parms->index = nla_get_u32(data[IFLA_GRE_ERSPAN_INDEX]);
1781 	} else if (parms->erspan_ver == 2) {
1782 		if (data[IFLA_GRE_ERSPAN_DIR])
1783 			parms->dir = nla_get_u8(data[IFLA_GRE_ERSPAN_DIR]);
1784 		if (data[IFLA_GRE_ERSPAN_HWID])
1785 			parms->hwid = nla_get_u16(data[IFLA_GRE_ERSPAN_HWID]);
1786 	}
1787 }
1788 
1789 static void ip6gre_netlink_parms(struct nlattr *data[],
1790 				struct __ip6_tnl_parm *parms)
1791 {
1792 	memset(parms, 0, sizeof(*parms));
1793 
1794 	if (!data)
1795 		return;
1796 
1797 	if (data[IFLA_GRE_LINK])
1798 		parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
1799 
1800 	if (data[IFLA_GRE_IFLAGS])
1801 		gre_flags_to_tnl_flags(parms->i_flags,
1802 				       nla_get_be16(data[IFLA_GRE_IFLAGS]));
1803 
1804 	if (data[IFLA_GRE_OFLAGS])
1805 		gre_flags_to_tnl_flags(parms->o_flags,
1806 				       nla_get_be16(data[IFLA_GRE_OFLAGS]));
1807 
1808 	if (data[IFLA_GRE_IKEY])
1809 		parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
1810 
1811 	if (data[IFLA_GRE_OKEY])
1812 		parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
1813 
1814 	if (data[IFLA_GRE_LOCAL])
1815 		parms->laddr = nla_get_in6_addr(data[IFLA_GRE_LOCAL]);
1816 
1817 	if (data[IFLA_GRE_REMOTE])
1818 		parms->raddr = nla_get_in6_addr(data[IFLA_GRE_REMOTE]);
1819 
1820 	if (data[IFLA_GRE_TTL])
1821 		parms->hop_limit = nla_get_u8(data[IFLA_GRE_TTL]);
1822 
1823 	if (data[IFLA_GRE_ENCAP_LIMIT])
1824 		parms->encap_limit = nla_get_u8(data[IFLA_GRE_ENCAP_LIMIT]);
1825 
1826 	if (data[IFLA_GRE_FLOWINFO])
1827 		parms->flowinfo = nla_get_be32(data[IFLA_GRE_FLOWINFO]);
1828 
1829 	if (data[IFLA_GRE_FLAGS])
1830 		parms->flags = nla_get_u32(data[IFLA_GRE_FLAGS]);
1831 
1832 	if (data[IFLA_GRE_FWMARK])
1833 		parms->fwmark = nla_get_u32(data[IFLA_GRE_FWMARK]);
1834 
1835 	if (data[IFLA_GRE_COLLECT_METADATA])
1836 		parms->collect_md = true;
1837 }
1838 
1839 static int ip6gre_tap_init(struct net_device *dev)
1840 {
1841 	int ret;
1842 
1843 	ret = ip6gre_tunnel_init_common(dev);
1844 	if (ret)
1845 		return ret;
1846 
1847 	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1848 
1849 	return 0;
1850 }
1851 
1852 static const struct net_device_ops ip6gre_tap_netdev_ops = {
1853 	.ndo_init = ip6gre_tap_init,
1854 	.ndo_uninit = ip6gre_tunnel_uninit,
1855 	.ndo_start_xmit = ip6gre_tunnel_xmit,
1856 	.ndo_set_mac_address = eth_mac_addr,
1857 	.ndo_validate_addr = eth_validate_addr,
1858 	.ndo_change_mtu = ip6_tnl_change_mtu,
1859 	.ndo_get_iflink = ip6_tnl_get_iflink,
1860 };
1861 
1862 static int ip6erspan_calc_hlen(struct ip6_tnl *tunnel)
1863 {
1864 	int t_hlen;
1865 
1866 	tunnel->tun_hlen = 8;
1867 	tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen +
1868 		       erspan_hdr_len(tunnel->parms.erspan_ver);
1869 
1870 	t_hlen = tunnel->hlen + sizeof(struct ipv6hdr);
1871 	tunnel->dev->needed_headroom = LL_MAX_HEADER + t_hlen;
1872 	return t_hlen;
1873 }
1874 
1875 static int ip6erspan_tap_init(struct net_device *dev)
1876 {
1877 	struct ip6_tnl *tunnel;
1878 	int t_hlen;
1879 	int ret;
1880 
1881 	tunnel = netdev_priv(dev);
1882 
1883 	tunnel->dev = dev;
1884 	tunnel->net = dev_net(dev);
1885 	strcpy(tunnel->parms.name, dev->name);
1886 
1887 	ret = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL);
1888 	if (ret)
1889 		return ret;
1890 
1891 	ret = gro_cells_init(&tunnel->gro_cells, dev);
1892 	if (ret)
1893 		goto cleanup_dst_cache_init;
1894 
1895 	t_hlen = ip6erspan_calc_hlen(tunnel);
1896 	dev->mtu = ETH_DATA_LEN - t_hlen;
1897 	if (dev->type == ARPHRD_ETHER)
1898 		dev->mtu -= ETH_HLEN;
1899 	if (!(tunnel->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1900 		dev->mtu -= 8;
1901 
1902 	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1903 	ip6erspan_tnl_link_config(tunnel, 1);
1904 
1905 	netdev_hold(dev, &tunnel->dev_tracker, GFP_KERNEL);
1906 	netdev_lockdep_set_classes(dev);
1907 	return 0;
1908 
1909 cleanup_dst_cache_init:
1910 	dst_cache_destroy(&tunnel->dst_cache);
1911 	return ret;
1912 }
1913 
1914 static const struct net_device_ops ip6erspan_netdev_ops = {
1915 	.ndo_init =		ip6erspan_tap_init,
1916 	.ndo_uninit =		ip6erspan_tunnel_uninit,
1917 	.ndo_start_xmit =	ip6erspan_tunnel_xmit,
1918 	.ndo_set_mac_address =	eth_mac_addr,
1919 	.ndo_validate_addr =	eth_validate_addr,
1920 	.ndo_change_mtu =	ip6_tnl_change_mtu,
1921 	.ndo_get_iflink =	ip6_tnl_get_iflink,
1922 };
1923 
1924 static void ip6gre_tap_setup(struct net_device *dev)
1925 {
1926 
1927 	ether_setup(dev);
1928 
1929 	dev->max_mtu = 0;
1930 	dev->netdev_ops = &ip6gre_tap_netdev_ops;
1931 	dev->needs_free_netdev = true;
1932 	dev->priv_destructor = ip6gre_dev_free;
1933 
1934 	dev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS;
1935 	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1936 	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1937 	netif_keep_dst(dev);
1938 }
1939 
1940 static bool ip6gre_netlink_encap_parms(struct nlattr *data[],
1941 				       struct ip_tunnel_encap *ipencap)
1942 {
1943 	bool ret = false;
1944 
1945 	memset(ipencap, 0, sizeof(*ipencap));
1946 
1947 	if (!data)
1948 		return ret;
1949 
1950 	if (data[IFLA_GRE_ENCAP_TYPE]) {
1951 		ret = true;
1952 		ipencap->type = nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]);
1953 	}
1954 
1955 	if (data[IFLA_GRE_ENCAP_FLAGS]) {
1956 		ret = true;
1957 		ipencap->flags = nla_get_u16(data[IFLA_GRE_ENCAP_FLAGS]);
1958 	}
1959 
1960 	if (data[IFLA_GRE_ENCAP_SPORT]) {
1961 		ret = true;
1962 		ipencap->sport = nla_get_be16(data[IFLA_GRE_ENCAP_SPORT]);
1963 	}
1964 
1965 	if (data[IFLA_GRE_ENCAP_DPORT]) {
1966 		ret = true;
1967 		ipencap->dport = nla_get_be16(data[IFLA_GRE_ENCAP_DPORT]);
1968 	}
1969 
1970 	return ret;
1971 }
1972 
1973 static int ip6gre_newlink_common(struct net *src_net, struct net_device *dev,
1974 				 struct nlattr *tb[], struct nlattr *data[],
1975 				 struct netlink_ext_ack *extack)
1976 {
1977 	struct ip6_tnl *nt;
1978 	struct ip_tunnel_encap ipencap;
1979 	int err;
1980 
1981 	nt = netdev_priv(dev);
1982 
1983 	if (ip6gre_netlink_encap_parms(data, &ipencap)) {
1984 		int err = ip6_tnl_encap_setup(nt, &ipencap);
1985 
1986 		if (err < 0)
1987 			return err;
1988 	}
1989 
1990 	if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
1991 		eth_hw_addr_random(dev);
1992 
1993 	nt->dev = dev;
1994 	nt->net = dev_net(dev);
1995 
1996 	err = register_netdevice(dev);
1997 	if (err)
1998 		goto out;
1999 
2000 	if (tb[IFLA_MTU])
2001 		ip6_tnl_change_mtu(dev, nla_get_u32(tb[IFLA_MTU]));
2002 
2003 out:
2004 	return err;
2005 }
2006 
2007 static int ip6gre_newlink(struct net *src_net, struct net_device *dev,
2008 			  struct nlattr *tb[], struct nlattr *data[],
2009 			  struct netlink_ext_ack *extack)
2010 {
2011 	struct ip6_tnl *nt = netdev_priv(dev);
2012 	struct net *net = dev_net(dev);
2013 	struct ip6gre_net *ign;
2014 	int err;
2015 
2016 	ip6gre_netlink_parms(data, &nt->parms);
2017 	ign = net_generic(net, ip6gre_net_id);
2018 
2019 	if (nt->parms.collect_md) {
2020 		if (rtnl_dereference(ign->collect_md_tun))
2021 			return -EEXIST;
2022 	} else {
2023 		if (ip6gre_tunnel_find(net, &nt->parms, dev->type))
2024 			return -EEXIST;
2025 	}
2026 
2027 	err = ip6gre_newlink_common(src_net, dev, tb, data, extack);
2028 	if (!err) {
2029 		ip6gre_tnl_link_config(nt, !tb[IFLA_MTU]);
2030 		ip6gre_tunnel_link_md(ign, nt);
2031 		ip6gre_tunnel_link(net_generic(net, ip6gre_net_id), nt);
2032 	}
2033 	return err;
2034 }
2035 
2036 static struct ip6_tnl *
2037 ip6gre_changelink_common(struct net_device *dev, struct nlattr *tb[],
2038 			 struct nlattr *data[], struct __ip6_tnl_parm *p_p,
2039 			 struct netlink_ext_ack *extack)
2040 {
2041 	struct ip6_tnl *t, *nt = netdev_priv(dev);
2042 	struct net *net = nt->net;
2043 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
2044 	struct ip_tunnel_encap ipencap;
2045 
2046 	if (dev == ign->fb_tunnel_dev)
2047 		return ERR_PTR(-EINVAL);
2048 
2049 	if (ip6gre_netlink_encap_parms(data, &ipencap)) {
2050 		int err = ip6_tnl_encap_setup(nt, &ipencap);
2051 
2052 		if (err < 0)
2053 			return ERR_PTR(err);
2054 	}
2055 
2056 	ip6gre_netlink_parms(data, p_p);
2057 
2058 	t = ip6gre_tunnel_locate(net, p_p, 0);
2059 
2060 	if (t) {
2061 		if (t->dev != dev)
2062 			return ERR_PTR(-EEXIST);
2063 	} else {
2064 		t = nt;
2065 	}
2066 
2067 	return t;
2068 }
2069 
2070 static int ip6gre_changelink(struct net_device *dev, struct nlattr *tb[],
2071 			     struct nlattr *data[],
2072 			     struct netlink_ext_ack *extack)
2073 {
2074 	struct ip6_tnl *t = netdev_priv(dev);
2075 	struct ip6gre_net *ign = net_generic(t->net, ip6gre_net_id);
2076 	struct __ip6_tnl_parm p;
2077 
2078 	t = ip6gre_changelink_common(dev, tb, data, &p, extack);
2079 	if (IS_ERR(t))
2080 		return PTR_ERR(t);
2081 
2082 	ip6gre_tunnel_unlink_md(ign, t);
2083 	ip6gre_tunnel_unlink(ign, t);
2084 	ip6gre_tnl_change(t, &p, !tb[IFLA_MTU]);
2085 	ip6gre_tunnel_link_md(ign, t);
2086 	ip6gre_tunnel_link(ign, t);
2087 	return 0;
2088 }
2089 
2090 static void ip6gre_dellink(struct net_device *dev, struct list_head *head)
2091 {
2092 	struct net *net = dev_net(dev);
2093 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
2094 
2095 	if (dev != ign->fb_tunnel_dev)
2096 		unregister_netdevice_queue(dev, head);
2097 }
2098 
2099 static size_t ip6gre_get_size(const struct net_device *dev)
2100 {
2101 	return
2102 		/* IFLA_GRE_LINK */
2103 		nla_total_size(4) +
2104 		/* IFLA_GRE_IFLAGS */
2105 		nla_total_size(2) +
2106 		/* IFLA_GRE_OFLAGS */
2107 		nla_total_size(2) +
2108 		/* IFLA_GRE_IKEY */
2109 		nla_total_size(4) +
2110 		/* IFLA_GRE_OKEY */
2111 		nla_total_size(4) +
2112 		/* IFLA_GRE_LOCAL */
2113 		nla_total_size(sizeof(struct in6_addr)) +
2114 		/* IFLA_GRE_REMOTE */
2115 		nla_total_size(sizeof(struct in6_addr)) +
2116 		/* IFLA_GRE_TTL */
2117 		nla_total_size(1) +
2118 		/* IFLA_GRE_ENCAP_LIMIT */
2119 		nla_total_size(1) +
2120 		/* IFLA_GRE_FLOWINFO */
2121 		nla_total_size(4) +
2122 		/* IFLA_GRE_FLAGS */
2123 		nla_total_size(4) +
2124 		/* IFLA_GRE_ENCAP_TYPE */
2125 		nla_total_size(2) +
2126 		/* IFLA_GRE_ENCAP_FLAGS */
2127 		nla_total_size(2) +
2128 		/* IFLA_GRE_ENCAP_SPORT */
2129 		nla_total_size(2) +
2130 		/* IFLA_GRE_ENCAP_DPORT */
2131 		nla_total_size(2) +
2132 		/* IFLA_GRE_COLLECT_METADATA */
2133 		nla_total_size(0) +
2134 		/* IFLA_GRE_FWMARK */
2135 		nla_total_size(4) +
2136 		/* IFLA_GRE_ERSPAN_INDEX */
2137 		nla_total_size(4) +
2138 		0;
2139 }
2140 
2141 static int ip6gre_fill_info(struct sk_buff *skb, const struct net_device *dev)
2142 {
2143 	struct ip6_tnl *t = netdev_priv(dev);
2144 	struct __ip6_tnl_parm *p = &t->parms;
2145 	IP_TUNNEL_DECLARE_FLAGS(o_flags);
2146 
2147 	ip_tunnel_flags_copy(o_flags, p->o_flags);
2148 
2149 	if (p->erspan_ver == 1 || p->erspan_ver == 2) {
2150 		if (!p->collect_md)
2151 			__set_bit(IP_TUNNEL_KEY_BIT, o_flags);
2152 
2153 		if (nla_put_u8(skb, IFLA_GRE_ERSPAN_VER, p->erspan_ver))
2154 			goto nla_put_failure;
2155 
2156 		if (p->erspan_ver == 1) {
2157 			if (nla_put_u32(skb, IFLA_GRE_ERSPAN_INDEX, p->index))
2158 				goto nla_put_failure;
2159 		} else {
2160 			if (nla_put_u8(skb, IFLA_GRE_ERSPAN_DIR, p->dir))
2161 				goto nla_put_failure;
2162 			if (nla_put_u16(skb, IFLA_GRE_ERSPAN_HWID, p->hwid))
2163 				goto nla_put_failure;
2164 		}
2165 	}
2166 
2167 	if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
2168 	    nla_put_be16(skb, IFLA_GRE_IFLAGS,
2169 			 gre_tnl_flags_to_gre_flags(p->i_flags)) ||
2170 	    nla_put_be16(skb, IFLA_GRE_OFLAGS,
2171 			 gre_tnl_flags_to_gre_flags(o_flags)) ||
2172 	    nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
2173 	    nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
2174 	    nla_put_in6_addr(skb, IFLA_GRE_LOCAL, &p->laddr) ||
2175 	    nla_put_in6_addr(skb, IFLA_GRE_REMOTE, &p->raddr) ||
2176 	    nla_put_u8(skb, IFLA_GRE_TTL, p->hop_limit) ||
2177 	    nla_put_u8(skb, IFLA_GRE_ENCAP_LIMIT, p->encap_limit) ||
2178 	    nla_put_be32(skb, IFLA_GRE_FLOWINFO, p->flowinfo) ||
2179 	    nla_put_u32(skb, IFLA_GRE_FLAGS, p->flags) ||
2180 	    nla_put_u32(skb, IFLA_GRE_FWMARK, p->fwmark))
2181 		goto nla_put_failure;
2182 
2183 	if (nla_put_u16(skb, IFLA_GRE_ENCAP_TYPE,
2184 			t->encap.type) ||
2185 	    nla_put_be16(skb, IFLA_GRE_ENCAP_SPORT,
2186 			 t->encap.sport) ||
2187 	    nla_put_be16(skb, IFLA_GRE_ENCAP_DPORT,
2188 			 t->encap.dport) ||
2189 	    nla_put_u16(skb, IFLA_GRE_ENCAP_FLAGS,
2190 			t->encap.flags))
2191 		goto nla_put_failure;
2192 
2193 	if (p->collect_md) {
2194 		if (nla_put_flag(skb, IFLA_GRE_COLLECT_METADATA))
2195 			goto nla_put_failure;
2196 	}
2197 
2198 	return 0;
2199 
2200 nla_put_failure:
2201 	return -EMSGSIZE;
2202 }
2203 
2204 static const struct nla_policy ip6gre_policy[IFLA_GRE_MAX + 1] = {
2205 	[IFLA_GRE_LINK]        = { .type = NLA_U32 },
2206 	[IFLA_GRE_IFLAGS]      = { .type = NLA_U16 },
2207 	[IFLA_GRE_OFLAGS]      = { .type = NLA_U16 },
2208 	[IFLA_GRE_IKEY]        = { .type = NLA_U32 },
2209 	[IFLA_GRE_OKEY]        = { .type = NLA_U32 },
2210 	[IFLA_GRE_LOCAL]       = { .len = sizeof_field(struct ipv6hdr, saddr) },
2211 	[IFLA_GRE_REMOTE]      = { .len = sizeof_field(struct ipv6hdr, daddr) },
2212 	[IFLA_GRE_TTL]         = { .type = NLA_U8 },
2213 	[IFLA_GRE_ENCAP_LIMIT] = { .type = NLA_U8 },
2214 	[IFLA_GRE_FLOWINFO]    = { .type = NLA_U32 },
2215 	[IFLA_GRE_FLAGS]       = { .type = NLA_U32 },
2216 	[IFLA_GRE_ENCAP_TYPE]   = { .type = NLA_U16 },
2217 	[IFLA_GRE_ENCAP_FLAGS]  = { .type = NLA_U16 },
2218 	[IFLA_GRE_ENCAP_SPORT]  = { .type = NLA_U16 },
2219 	[IFLA_GRE_ENCAP_DPORT]  = { .type = NLA_U16 },
2220 	[IFLA_GRE_COLLECT_METADATA] = { .type = NLA_FLAG },
2221 	[IFLA_GRE_FWMARK]       = { .type = NLA_U32 },
2222 	[IFLA_GRE_ERSPAN_INDEX] = { .type = NLA_U32 },
2223 	[IFLA_GRE_ERSPAN_VER]	= { .type = NLA_U8 },
2224 	[IFLA_GRE_ERSPAN_DIR]	= { .type = NLA_U8 },
2225 	[IFLA_GRE_ERSPAN_HWID]	= { .type = NLA_U16 },
2226 };
2227 
2228 static void ip6erspan_tap_setup(struct net_device *dev)
2229 {
2230 	ether_setup(dev);
2231 
2232 	dev->max_mtu = 0;
2233 	dev->netdev_ops = &ip6erspan_netdev_ops;
2234 	dev->needs_free_netdev = true;
2235 	dev->priv_destructor = ip6gre_dev_free;
2236 
2237 	dev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS;
2238 	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
2239 	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
2240 	netif_keep_dst(dev);
2241 }
2242 
2243 static int ip6erspan_newlink(struct net *src_net, struct net_device *dev,
2244 			     struct nlattr *tb[], struct nlattr *data[],
2245 			     struct netlink_ext_ack *extack)
2246 {
2247 	struct ip6_tnl *nt = netdev_priv(dev);
2248 	struct net *net = dev_net(dev);
2249 	struct ip6gre_net *ign;
2250 	int err;
2251 
2252 	ip6gre_netlink_parms(data, &nt->parms);
2253 	ip6erspan_set_version(data, &nt->parms);
2254 	ign = net_generic(net, ip6gre_net_id);
2255 
2256 	if (nt->parms.collect_md) {
2257 		if (rtnl_dereference(ign->collect_md_tun_erspan))
2258 			return -EEXIST;
2259 	} else {
2260 		if (ip6gre_tunnel_find(net, &nt->parms, dev->type))
2261 			return -EEXIST;
2262 	}
2263 
2264 	err = ip6gre_newlink_common(src_net, dev, tb, data, extack);
2265 	if (!err) {
2266 		ip6erspan_tnl_link_config(nt, !tb[IFLA_MTU]);
2267 		ip6erspan_tunnel_link_md(ign, nt);
2268 		ip6gre_tunnel_link(net_generic(net, ip6gre_net_id), nt);
2269 	}
2270 	return err;
2271 }
2272 
2273 static void ip6erspan_tnl_link_config(struct ip6_tnl *t, int set_mtu)
2274 {
2275 	ip6gre_tnl_link_config_common(t);
2276 	ip6gre_tnl_link_config_route(t, set_mtu, ip6erspan_calc_hlen(t));
2277 }
2278 
2279 static int ip6erspan_tnl_change(struct ip6_tnl *t,
2280 				const struct __ip6_tnl_parm *p, int set_mtu)
2281 {
2282 	ip6gre_tnl_copy_tnl_parm(t, p);
2283 	ip6erspan_tnl_link_config(t, set_mtu);
2284 	return 0;
2285 }
2286 
2287 static int ip6erspan_changelink(struct net_device *dev, struct nlattr *tb[],
2288 				struct nlattr *data[],
2289 				struct netlink_ext_ack *extack)
2290 {
2291 	struct ip6gre_net *ign = net_generic(dev_net(dev), ip6gre_net_id);
2292 	struct __ip6_tnl_parm p;
2293 	struct ip6_tnl *t;
2294 
2295 	t = ip6gre_changelink_common(dev, tb, data, &p, extack);
2296 	if (IS_ERR(t))
2297 		return PTR_ERR(t);
2298 
2299 	ip6erspan_set_version(data, &p);
2300 	ip6gre_tunnel_unlink_md(ign, t);
2301 	ip6gre_tunnel_unlink(ign, t);
2302 	ip6erspan_tnl_change(t, &p, !tb[IFLA_MTU]);
2303 	ip6erspan_tunnel_link_md(ign, t);
2304 	ip6gre_tunnel_link(ign, t);
2305 	return 0;
2306 }
2307 
2308 static struct rtnl_link_ops ip6gre_link_ops __read_mostly = {
2309 	.kind		= "ip6gre",
2310 	.maxtype	= IFLA_GRE_MAX,
2311 	.policy		= ip6gre_policy,
2312 	.priv_size	= sizeof(struct ip6_tnl),
2313 	.setup		= ip6gre_tunnel_setup,
2314 	.validate	= ip6gre_tunnel_validate,
2315 	.newlink	= ip6gre_newlink,
2316 	.changelink	= ip6gre_changelink,
2317 	.dellink	= ip6gre_dellink,
2318 	.get_size	= ip6gre_get_size,
2319 	.fill_info	= ip6gre_fill_info,
2320 	.get_link_net	= ip6_tnl_get_link_net,
2321 };
2322 
2323 static struct rtnl_link_ops ip6gre_tap_ops __read_mostly = {
2324 	.kind		= "ip6gretap",
2325 	.maxtype	= IFLA_GRE_MAX,
2326 	.policy		= ip6gre_policy,
2327 	.priv_size	= sizeof(struct ip6_tnl),
2328 	.setup		= ip6gre_tap_setup,
2329 	.validate	= ip6gre_tap_validate,
2330 	.newlink	= ip6gre_newlink,
2331 	.changelink	= ip6gre_changelink,
2332 	.get_size	= ip6gre_get_size,
2333 	.fill_info	= ip6gre_fill_info,
2334 	.get_link_net	= ip6_tnl_get_link_net,
2335 };
2336 
2337 static struct rtnl_link_ops ip6erspan_tap_ops __read_mostly = {
2338 	.kind		= "ip6erspan",
2339 	.maxtype	= IFLA_GRE_MAX,
2340 	.policy		= ip6gre_policy,
2341 	.priv_size	= sizeof(struct ip6_tnl),
2342 	.setup		= ip6erspan_tap_setup,
2343 	.validate	= ip6erspan_tap_validate,
2344 	.newlink	= ip6erspan_newlink,
2345 	.changelink	= ip6erspan_changelink,
2346 	.get_size	= ip6gre_get_size,
2347 	.fill_info	= ip6gre_fill_info,
2348 	.get_link_net	= ip6_tnl_get_link_net,
2349 };
2350 
2351 /*
2352  *	And now the modules code and kernel interface.
2353  */
2354 
2355 static int __init ip6gre_init(void)
2356 {
2357 	int err;
2358 
2359 	pr_info("GRE over IPv6 tunneling driver\n");
2360 
2361 	err = register_pernet_device(&ip6gre_net_ops);
2362 	if (err < 0)
2363 		return err;
2364 
2365 	err = inet6_add_protocol(&ip6gre_protocol, IPPROTO_GRE);
2366 	if (err < 0) {
2367 		pr_info("%s: can't add protocol\n", __func__);
2368 		goto add_proto_failed;
2369 	}
2370 
2371 	err = rtnl_link_register(&ip6gre_link_ops);
2372 	if (err < 0)
2373 		goto rtnl_link_failed;
2374 
2375 	err = rtnl_link_register(&ip6gre_tap_ops);
2376 	if (err < 0)
2377 		goto tap_ops_failed;
2378 
2379 	err = rtnl_link_register(&ip6erspan_tap_ops);
2380 	if (err < 0)
2381 		goto erspan_link_failed;
2382 
2383 out:
2384 	return err;
2385 
2386 erspan_link_failed:
2387 	rtnl_link_unregister(&ip6gre_tap_ops);
2388 tap_ops_failed:
2389 	rtnl_link_unregister(&ip6gre_link_ops);
2390 rtnl_link_failed:
2391 	inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
2392 add_proto_failed:
2393 	unregister_pernet_device(&ip6gre_net_ops);
2394 	goto out;
2395 }
2396 
2397 static void __exit ip6gre_fini(void)
2398 {
2399 	rtnl_link_unregister(&ip6gre_tap_ops);
2400 	rtnl_link_unregister(&ip6gre_link_ops);
2401 	rtnl_link_unregister(&ip6erspan_tap_ops);
2402 	inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
2403 	unregister_pernet_device(&ip6gre_net_ops);
2404 }
2405 
2406 module_init(ip6gre_init);
2407 module_exit(ip6gre_fini);
2408 MODULE_LICENSE("GPL");
2409 MODULE_AUTHOR("D. Kozlov <xeb@mail.ru>");
2410 MODULE_DESCRIPTION("GRE over IPv6 tunneling device");
2411 MODULE_ALIAS_RTNL_LINK("ip6gre");
2412 MODULE_ALIAS_RTNL_LINK("ip6gretap");
2413 MODULE_ALIAS_RTNL_LINK("ip6erspan");
2414 MODULE_ALIAS_NETDEV("ip6gre0");
2415