xref: /openbmc/linux/net/ipv6/ip6_gre.c (revision f7d84fa7)
1 /*
2  *	GRE over IPv6 protocol decoder.
3  *
4  *	Authors: Dmitry Kozlov (xeb@mail.ru)
5  *
6  *	This program is free software; you can redistribute it and/or
7  *	modify it under the terms of the GNU General Public License
8  *	as published by the Free Software Foundation; either version
9  *	2 of the License, or (at your option) any later version.
10  *
11  */
12 
13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14 
15 #include <linux/capability.h>
16 #include <linux/module.h>
17 #include <linux/types.h>
18 #include <linux/kernel.h>
19 #include <linux/slab.h>
20 #include <linux/uaccess.h>
21 #include <linux/skbuff.h>
22 #include <linux/netdevice.h>
23 #include <linux/in.h>
24 #include <linux/tcp.h>
25 #include <linux/udp.h>
26 #include <linux/if_arp.h>
27 #include <linux/init.h>
28 #include <linux/in6.h>
29 #include <linux/inetdevice.h>
30 #include <linux/igmp.h>
31 #include <linux/netfilter_ipv4.h>
32 #include <linux/etherdevice.h>
33 #include <linux/if_ether.h>
34 #include <linux/hash.h>
35 #include <linux/if_tunnel.h>
36 #include <linux/ip6_tunnel.h>
37 
38 #include <net/sock.h>
39 #include <net/ip.h>
40 #include <net/ip_tunnels.h>
41 #include <net/icmp.h>
42 #include <net/protocol.h>
43 #include <net/addrconf.h>
44 #include <net/arp.h>
45 #include <net/checksum.h>
46 #include <net/dsfield.h>
47 #include <net/inet_ecn.h>
48 #include <net/xfrm.h>
49 #include <net/net_namespace.h>
50 #include <net/netns/generic.h>
51 #include <net/rtnetlink.h>
52 
53 #include <net/ipv6.h>
54 #include <net/ip6_fib.h>
55 #include <net/ip6_route.h>
56 #include <net/ip6_tunnel.h>
57 #include <net/gre.h>
58 
59 
60 static bool log_ecn_error = true;
61 module_param(log_ecn_error, bool, 0644);
62 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
63 
64 #define IP6_GRE_HASH_SIZE_SHIFT  5
65 #define IP6_GRE_HASH_SIZE (1 << IP6_GRE_HASH_SIZE_SHIFT)
66 
67 static unsigned int ip6gre_net_id __read_mostly;
68 struct ip6gre_net {
69 	struct ip6_tnl __rcu *tunnels[4][IP6_GRE_HASH_SIZE];
70 
71 	struct net_device *fb_tunnel_dev;
72 };
73 
74 static struct rtnl_link_ops ip6gre_link_ops __read_mostly;
75 static struct rtnl_link_ops ip6gre_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 
81 /* Tunnel hash table */
82 
83 /*
84    4 hash tables:
85 
86    3: (remote,local)
87    2: (remote,*)
88    1: (*,local)
89    0: (*,*)
90 
91    We require exact key match i.e. if a key is present in packet
92    it will match only tunnel with the same key; if it is not present,
93    it will match only keyless tunnel.
94 
95    All keysless packets, if not matched configured keyless tunnels
96    will match fallback tunnel.
97  */
98 
99 #define HASH_KEY(key) (((__force u32)key^((__force u32)key>>4))&(IP6_GRE_HASH_SIZE - 1))
100 static u32 HASH_ADDR(const struct in6_addr *addr)
101 {
102 	u32 hash = ipv6_addr_hash(addr);
103 
104 	return hash_32(hash, IP6_GRE_HASH_SIZE_SHIFT);
105 }
106 
107 #define tunnels_r_l	tunnels[3]
108 #define tunnels_r	tunnels[2]
109 #define tunnels_l	tunnels[1]
110 #define tunnels_wc	tunnels[0]
111 
112 /* Given src, dst and key, find appropriate for input tunnel. */
113 
114 static struct ip6_tnl *ip6gre_tunnel_lookup(struct net_device *dev,
115 		const struct in6_addr *remote, const struct in6_addr *local,
116 		__be32 key, __be16 gre_proto)
117 {
118 	struct net *net = dev_net(dev);
119 	int link = dev->ifindex;
120 	unsigned int h0 = HASH_ADDR(remote);
121 	unsigned int h1 = HASH_KEY(key);
122 	struct ip6_tnl *t, *cand = NULL;
123 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
124 	int dev_type = (gre_proto == htons(ETH_P_TEB)) ?
125 		       ARPHRD_ETHER : ARPHRD_IP6GRE;
126 	int score, cand_score = 4;
127 
128 	for_each_ip_tunnel_rcu(t, ign->tunnels_r_l[h0 ^ h1]) {
129 		if (!ipv6_addr_equal(local, &t->parms.laddr) ||
130 		    !ipv6_addr_equal(remote, &t->parms.raddr) ||
131 		    key != t->parms.i_key ||
132 		    !(t->dev->flags & IFF_UP))
133 			continue;
134 
135 		if (t->dev->type != ARPHRD_IP6GRE &&
136 		    t->dev->type != dev_type)
137 			continue;
138 
139 		score = 0;
140 		if (t->parms.link != link)
141 			score |= 1;
142 		if (t->dev->type != dev_type)
143 			score |= 2;
144 		if (score == 0)
145 			return t;
146 
147 		if (score < cand_score) {
148 			cand = t;
149 			cand_score = score;
150 		}
151 	}
152 
153 	for_each_ip_tunnel_rcu(t, ign->tunnels_r[h0 ^ h1]) {
154 		if (!ipv6_addr_equal(remote, &t->parms.raddr) ||
155 		    key != t->parms.i_key ||
156 		    !(t->dev->flags & IFF_UP))
157 			continue;
158 
159 		if (t->dev->type != ARPHRD_IP6GRE &&
160 		    t->dev->type != dev_type)
161 			continue;
162 
163 		score = 0;
164 		if (t->parms.link != link)
165 			score |= 1;
166 		if (t->dev->type != dev_type)
167 			score |= 2;
168 		if (score == 0)
169 			return t;
170 
171 		if (score < cand_score) {
172 			cand = t;
173 			cand_score = score;
174 		}
175 	}
176 
177 	for_each_ip_tunnel_rcu(t, ign->tunnels_l[h1]) {
178 		if ((!ipv6_addr_equal(local, &t->parms.laddr) &&
179 			  (!ipv6_addr_equal(local, &t->parms.raddr) ||
180 				 !ipv6_addr_is_multicast(local))) ||
181 		    key != t->parms.i_key ||
182 		    !(t->dev->flags & IFF_UP))
183 			continue;
184 
185 		if (t->dev->type != ARPHRD_IP6GRE &&
186 		    t->dev->type != dev_type)
187 			continue;
188 
189 		score = 0;
190 		if (t->parms.link != link)
191 			score |= 1;
192 		if (t->dev->type != dev_type)
193 			score |= 2;
194 		if (score == 0)
195 			return t;
196 
197 		if (score < cand_score) {
198 			cand = t;
199 			cand_score = score;
200 		}
201 	}
202 
203 	for_each_ip_tunnel_rcu(t, ign->tunnels_wc[h1]) {
204 		if (t->parms.i_key != key ||
205 		    !(t->dev->flags & IFF_UP))
206 			continue;
207 
208 		if (t->dev->type != ARPHRD_IP6GRE &&
209 		    t->dev->type != dev_type)
210 			continue;
211 
212 		score = 0;
213 		if (t->parms.link != link)
214 			score |= 1;
215 		if (t->dev->type != dev_type)
216 			score |= 2;
217 		if (score == 0)
218 			return t;
219 
220 		if (score < cand_score) {
221 			cand = t;
222 			cand_score = score;
223 		}
224 	}
225 
226 	if (cand)
227 		return cand;
228 
229 	dev = ign->fb_tunnel_dev;
230 	if (dev->flags & IFF_UP)
231 		return netdev_priv(dev);
232 
233 	return NULL;
234 }
235 
236 static struct ip6_tnl __rcu **__ip6gre_bucket(struct ip6gre_net *ign,
237 		const struct __ip6_tnl_parm *p)
238 {
239 	const struct in6_addr *remote = &p->raddr;
240 	const struct in6_addr *local = &p->laddr;
241 	unsigned int h = HASH_KEY(p->i_key);
242 	int prio = 0;
243 
244 	if (!ipv6_addr_any(local))
245 		prio |= 1;
246 	if (!ipv6_addr_any(remote) && !ipv6_addr_is_multicast(remote)) {
247 		prio |= 2;
248 		h ^= HASH_ADDR(remote);
249 	}
250 
251 	return &ign->tunnels[prio][h];
252 }
253 
254 static inline struct ip6_tnl __rcu **ip6gre_bucket(struct ip6gre_net *ign,
255 		const struct ip6_tnl *t)
256 {
257 	return __ip6gre_bucket(ign, &t->parms);
258 }
259 
260 static void ip6gre_tunnel_link(struct ip6gre_net *ign, struct ip6_tnl *t)
261 {
262 	struct ip6_tnl __rcu **tp = ip6gre_bucket(ign, t);
263 
264 	rcu_assign_pointer(t->next, rtnl_dereference(*tp));
265 	rcu_assign_pointer(*tp, t);
266 }
267 
268 static void ip6gre_tunnel_unlink(struct ip6gre_net *ign, struct ip6_tnl *t)
269 {
270 	struct ip6_tnl __rcu **tp;
271 	struct ip6_tnl *iter;
272 
273 	for (tp = ip6gre_bucket(ign, t);
274 	     (iter = rtnl_dereference(*tp)) != NULL;
275 	     tp = &iter->next) {
276 		if (t == iter) {
277 			rcu_assign_pointer(*tp, t->next);
278 			break;
279 		}
280 	}
281 }
282 
283 static struct ip6_tnl *ip6gre_tunnel_find(struct net *net,
284 					   const struct __ip6_tnl_parm *parms,
285 					   int type)
286 {
287 	const struct in6_addr *remote = &parms->raddr;
288 	const struct in6_addr *local = &parms->laddr;
289 	__be32 key = parms->i_key;
290 	int link = parms->link;
291 	struct ip6_tnl *t;
292 	struct ip6_tnl __rcu **tp;
293 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
294 
295 	for (tp = __ip6gre_bucket(ign, parms);
296 	     (t = rtnl_dereference(*tp)) != NULL;
297 	     tp = &t->next)
298 		if (ipv6_addr_equal(local, &t->parms.laddr) &&
299 		    ipv6_addr_equal(remote, &t->parms.raddr) &&
300 		    key == t->parms.i_key &&
301 		    link == t->parms.link &&
302 		    type == t->dev->type)
303 			break;
304 
305 	return t;
306 }
307 
308 static struct ip6_tnl *ip6gre_tunnel_locate(struct net *net,
309 		const struct __ip6_tnl_parm *parms, int create)
310 {
311 	struct ip6_tnl *t, *nt;
312 	struct net_device *dev;
313 	char name[IFNAMSIZ];
314 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
315 
316 	t = ip6gre_tunnel_find(net, parms, ARPHRD_IP6GRE);
317 	if (t && create)
318 		return NULL;
319 	if (t || !create)
320 		return t;
321 
322 	if (parms->name[0])
323 		strlcpy(name, parms->name, IFNAMSIZ);
324 	else
325 		strcpy(name, "ip6gre%d");
326 
327 	dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
328 			   ip6gre_tunnel_setup);
329 	if (!dev)
330 		return NULL;
331 
332 	dev_net_set(dev, net);
333 
334 	nt = netdev_priv(dev);
335 	nt->parms = *parms;
336 	dev->rtnl_link_ops = &ip6gre_link_ops;
337 
338 	nt->dev = dev;
339 	nt->net = dev_net(dev);
340 	ip6gre_tnl_link_config(nt, 1);
341 
342 	if (register_netdevice(dev) < 0)
343 		goto failed_free;
344 
345 	/* Can use a lockless transmit, unless we generate output sequences */
346 	if (!(nt->parms.o_flags & TUNNEL_SEQ))
347 		dev->features |= NETIF_F_LLTX;
348 
349 	dev_hold(dev);
350 	ip6gre_tunnel_link(ign, nt);
351 	return nt;
352 
353 failed_free:
354 	free_netdev(dev);
355 	return NULL;
356 }
357 
358 static void ip6gre_tunnel_uninit(struct net_device *dev)
359 {
360 	struct ip6_tnl *t = netdev_priv(dev);
361 	struct ip6gre_net *ign = net_generic(t->net, ip6gre_net_id);
362 
363 	ip6gre_tunnel_unlink(ign, t);
364 	dst_cache_reset(&t->dst_cache);
365 	dev_put(dev);
366 }
367 
368 
369 static void ip6gre_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
370 		       u8 type, u8 code, int offset, __be32 info)
371 {
372 	const struct gre_base_hdr *greh;
373 	const struct ipv6hdr *ipv6h;
374 	int grehlen = sizeof(*greh);
375 	struct ip6_tnl *t;
376 	int key_off = 0;
377 	__be16 flags;
378 	__be32 key;
379 
380 	if (!pskb_may_pull(skb, offset + grehlen))
381 		return;
382 	greh = (const struct gre_base_hdr *)(skb->data + offset);
383 	flags = greh->flags;
384 	if (flags & (GRE_VERSION | GRE_ROUTING))
385 		return;
386 	if (flags & GRE_CSUM)
387 		grehlen += 4;
388 	if (flags & GRE_KEY) {
389 		key_off = grehlen + offset;
390 		grehlen += 4;
391 	}
392 
393 	if (!pskb_may_pull(skb, offset + grehlen))
394 		return;
395 	ipv6h = (const struct ipv6hdr *)skb->data;
396 	greh = (const struct gre_base_hdr *)(skb->data + offset);
397 	key = key_off ? *(__be32 *)(skb->data + key_off) : 0;
398 
399 	t = ip6gre_tunnel_lookup(skb->dev, &ipv6h->daddr, &ipv6h->saddr,
400 				 key, greh->protocol);
401 	if (!t)
402 		return;
403 
404 	switch (type) {
405 		__u32 teli;
406 		struct ipv6_tlv_tnl_enc_lim *tel;
407 		__u32 mtu;
408 	case ICMPV6_DEST_UNREACH:
409 		net_dbg_ratelimited("%s: Path to destination invalid or inactive!\n",
410 				    t->parms.name);
411 		break;
412 	case ICMPV6_TIME_EXCEED:
413 		if (code == ICMPV6_EXC_HOPLIMIT) {
414 			net_dbg_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
415 					    t->parms.name);
416 		}
417 		break;
418 	case ICMPV6_PARAMPROB:
419 		teli = 0;
420 		if (code == ICMPV6_HDR_FIELD)
421 			teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
422 
423 		if (teli && teli == be32_to_cpu(info) - 2) {
424 			tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
425 			if (tel->encap_limit == 0) {
426 				net_dbg_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
427 						    t->parms.name);
428 			}
429 		} else {
430 			net_dbg_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
431 					    t->parms.name);
432 		}
433 		break;
434 	case ICMPV6_PKT_TOOBIG:
435 		mtu = be32_to_cpu(info) - offset;
436 		if (mtu < IPV6_MIN_MTU)
437 			mtu = IPV6_MIN_MTU;
438 		t->dev->mtu = mtu;
439 		break;
440 	}
441 
442 	if (time_before(jiffies, t->err_time + IP6TUNNEL_ERR_TIMEO))
443 		t->err_count++;
444 	else
445 		t->err_count = 1;
446 	t->err_time = jiffies;
447 }
448 
449 static int ip6gre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi)
450 {
451 	const struct ipv6hdr *ipv6h;
452 	struct ip6_tnl *tunnel;
453 
454 	ipv6h = ipv6_hdr(skb);
455 	tunnel = ip6gre_tunnel_lookup(skb->dev,
456 				      &ipv6h->saddr, &ipv6h->daddr, tpi->key,
457 				      tpi->proto);
458 	if (tunnel) {
459 		ip6_tnl_rcv(tunnel, skb, tpi, NULL, false);
460 
461 		return PACKET_RCVD;
462 	}
463 
464 	return PACKET_REJECT;
465 }
466 
467 static int gre_rcv(struct sk_buff *skb)
468 {
469 	struct tnl_ptk_info tpi;
470 	bool csum_err = false;
471 	int hdr_len;
472 
473 	hdr_len = gre_parse_header(skb, &tpi, &csum_err, htons(ETH_P_IPV6), 0);
474 	if (hdr_len < 0)
475 		goto drop;
476 
477 	if (iptunnel_pull_header(skb, hdr_len, tpi.proto, false))
478 		goto drop;
479 
480 	if (ip6gre_rcv(skb, &tpi) == PACKET_RCVD)
481 		return 0;
482 
483 	icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
484 drop:
485 	kfree_skb(skb);
486 	return 0;
487 }
488 
489 static int gre_handle_offloads(struct sk_buff *skb, bool csum)
490 {
491 	return iptunnel_handle_offloads(skb,
492 					csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE);
493 }
494 
495 static netdev_tx_t __gre6_xmit(struct sk_buff *skb,
496 			       struct net_device *dev, __u8 dsfield,
497 			       struct flowi6 *fl6, int encap_limit,
498 			       __u32 *pmtu, __be16 proto)
499 {
500 	struct ip6_tnl *tunnel = netdev_priv(dev);
501 	__be16 protocol = (dev->type == ARPHRD_ETHER) ?
502 			  htons(ETH_P_TEB) : proto;
503 
504 	if (dev->type == ARPHRD_ETHER)
505 		IPCB(skb)->flags = 0;
506 
507 	if (dev->header_ops && dev->type == ARPHRD_IP6GRE)
508 		fl6->daddr = ((struct ipv6hdr *)skb->data)->daddr;
509 	else
510 		fl6->daddr = tunnel->parms.raddr;
511 
512 	if (tunnel->parms.o_flags & TUNNEL_SEQ)
513 		tunnel->o_seqno++;
514 
515 	/* Push GRE header. */
516 	gre_build_header(skb, tunnel->tun_hlen, tunnel->parms.o_flags,
517 			 protocol, tunnel->parms.o_key, htonl(tunnel->o_seqno));
518 
519 	return ip6_tnl_xmit(skb, dev, dsfield, fl6, encap_limit, pmtu,
520 			    NEXTHDR_GRE);
521 }
522 
523 static inline int ip6gre_xmit_ipv4(struct sk_buff *skb, struct net_device *dev)
524 {
525 	struct ip6_tnl *t = netdev_priv(dev);
526 	const struct iphdr  *iph = ip_hdr(skb);
527 	int encap_limit = -1;
528 	struct flowi6 fl6;
529 	__u8 dsfield;
530 	__u32 mtu;
531 	int err;
532 
533 	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
534 
535 	if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
536 		encap_limit = t->parms.encap_limit;
537 
538 	memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
539 
540 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
541 		dsfield = ipv4_get_dsfield(iph);
542 	else
543 		dsfield = ip6_tclass(t->parms.flowinfo);
544 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
545 		fl6.flowi6_mark = skb->mark;
546 	else
547 		fl6.flowi6_mark = t->parms.fwmark;
548 
549 	fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
550 
551 	err = gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM));
552 	if (err)
553 		return -1;
554 
555 	err = __gre6_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
556 			  skb->protocol);
557 	if (err != 0) {
558 		/* XXX: send ICMP error even if DF is not set. */
559 		if (err == -EMSGSIZE)
560 			icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
561 				  htonl(mtu));
562 		return -1;
563 	}
564 
565 	return 0;
566 }
567 
568 static inline int ip6gre_xmit_ipv6(struct sk_buff *skb, struct net_device *dev)
569 {
570 	struct ip6_tnl *t = netdev_priv(dev);
571 	struct ipv6hdr *ipv6h = ipv6_hdr(skb);
572 	int encap_limit = -1;
573 	__u16 offset;
574 	struct flowi6 fl6;
575 	__u8 dsfield;
576 	__u32 mtu;
577 	int err;
578 
579 	if (ipv6_addr_equal(&t->parms.raddr, &ipv6h->saddr))
580 		return -1;
581 
582 	offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
583 	/* ip6_tnl_parse_tlv_enc_lim() might have reallocated skb->head */
584 	ipv6h = ipv6_hdr(skb);
585 
586 	if (offset > 0) {
587 		struct ipv6_tlv_tnl_enc_lim *tel;
588 		tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset];
589 		if (tel->encap_limit == 0) {
590 			icmpv6_send(skb, ICMPV6_PARAMPROB,
591 				    ICMPV6_HDR_FIELD, offset + 2);
592 			return -1;
593 		}
594 		encap_limit = tel->encap_limit - 1;
595 	} else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
596 		encap_limit = t->parms.encap_limit;
597 
598 	memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
599 
600 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
601 		dsfield = ipv6_get_dsfield(ipv6h);
602 	else
603 		dsfield = ip6_tclass(t->parms.flowinfo);
604 
605 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
606 		fl6.flowlabel |= ip6_flowlabel(ipv6h);
607 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
608 		fl6.flowi6_mark = skb->mark;
609 	else
610 		fl6.flowi6_mark = t->parms.fwmark;
611 
612 	fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
613 
614 	if (gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM)))
615 		return -1;
616 
617 	err = __gre6_xmit(skb, dev, dsfield, &fl6, encap_limit,
618 			  &mtu, skb->protocol);
619 	if (err != 0) {
620 		if (err == -EMSGSIZE)
621 			icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
622 		return -1;
623 	}
624 
625 	return 0;
626 }
627 
628 /**
629  * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
630  *   @t: the outgoing tunnel device
631  *   @hdr: IPv6 header from the incoming packet
632  *
633  * Description:
634  *   Avoid trivial tunneling loop by checking that tunnel exit-point
635  *   doesn't match source of incoming packet.
636  *
637  * Return:
638  *   1 if conflict,
639  *   0 else
640  **/
641 
642 static inline bool ip6gre_tnl_addr_conflict(const struct ip6_tnl *t,
643 	const struct ipv6hdr *hdr)
644 {
645 	return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
646 }
647 
648 static int ip6gre_xmit_other(struct sk_buff *skb, struct net_device *dev)
649 {
650 	struct ip6_tnl *t = netdev_priv(dev);
651 	int encap_limit = -1;
652 	struct flowi6 fl6;
653 	__u32 mtu;
654 	int err;
655 
656 	if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
657 		encap_limit = t->parms.encap_limit;
658 
659 	memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
660 
661 	err = gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM));
662 	if (err)
663 		return err;
664 
665 	err = __gre6_xmit(skb, dev, 0, &fl6, encap_limit, &mtu, skb->protocol);
666 
667 	return err;
668 }
669 
670 static netdev_tx_t ip6gre_tunnel_xmit(struct sk_buff *skb,
671 	struct net_device *dev)
672 {
673 	struct ip6_tnl *t = netdev_priv(dev);
674 	struct net_device_stats *stats = &t->dev->stats;
675 	int ret;
676 
677 	if (!ip6_tnl_xmit_ctl(t, &t->parms.laddr, &t->parms.raddr))
678 		goto tx_err;
679 
680 	switch (skb->protocol) {
681 	case htons(ETH_P_IP):
682 		ret = ip6gre_xmit_ipv4(skb, dev);
683 		break;
684 	case htons(ETH_P_IPV6):
685 		ret = ip6gre_xmit_ipv6(skb, dev);
686 		break;
687 	default:
688 		ret = ip6gre_xmit_other(skb, dev);
689 		break;
690 	}
691 
692 	if (ret < 0)
693 		goto tx_err;
694 
695 	return NETDEV_TX_OK;
696 
697 tx_err:
698 	stats->tx_errors++;
699 	stats->tx_dropped++;
700 	kfree_skb(skb);
701 	return NETDEV_TX_OK;
702 }
703 
704 static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu)
705 {
706 	struct net_device *dev = t->dev;
707 	struct __ip6_tnl_parm *p = &t->parms;
708 	struct flowi6 *fl6 = &t->fl.u.ip6;
709 	int t_hlen;
710 
711 	if (dev->type != ARPHRD_ETHER) {
712 		memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
713 		memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
714 	}
715 
716 	/* Set up flowi template */
717 	fl6->saddr = p->laddr;
718 	fl6->daddr = p->raddr;
719 	fl6->flowi6_oif = p->link;
720 	fl6->flowlabel = 0;
721 	fl6->flowi6_proto = IPPROTO_GRE;
722 
723 	if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
724 		fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
725 	if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
726 		fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
727 
728 	p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
729 	p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
730 
731 	if (p->flags&IP6_TNL_F_CAP_XMIT &&
732 			p->flags&IP6_TNL_F_CAP_RCV && dev->type != ARPHRD_ETHER)
733 		dev->flags |= IFF_POINTOPOINT;
734 	else
735 		dev->flags &= ~IFF_POINTOPOINT;
736 
737 	t->tun_hlen = gre_calc_hlen(t->parms.o_flags);
738 
739 	t->hlen = t->encap_hlen + t->tun_hlen;
740 
741 	t_hlen = t->hlen + sizeof(struct ipv6hdr);
742 
743 	if (p->flags & IP6_TNL_F_CAP_XMIT) {
744 		int strict = (ipv6_addr_type(&p->raddr) &
745 			      (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
746 
747 		struct rt6_info *rt = rt6_lookup(t->net,
748 						 &p->raddr, &p->laddr,
749 						 p->link, strict);
750 
751 		if (!rt)
752 			return;
753 
754 		if (rt->dst.dev) {
755 			dev->hard_header_len = rt->dst.dev->hard_header_len +
756 					       t_hlen;
757 
758 			if (set_mtu) {
759 				dev->mtu = rt->dst.dev->mtu - t_hlen;
760 				if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
761 					dev->mtu -= 8;
762 				if (dev->type == ARPHRD_ETHER)
763 					dev->mtu -= ETH_HLEN;
764 
765 				if (dev->mtu < IPV6_MIN_MTU)
766 					dev->mtu = IPV6_MIN_MTU;
767 			}
768 		}
769 		ip6_rt_put(rt);
770 	}
771 }
772 
773 static int ip6gre_tnl_change(struct ip6_tnl *t,
774 	const struct __ip6_tnl_parm *p, int set_mtu)
775 {
776 	t->parms.laddr = p->laddr;
777 	t->parms.raddr = p->raddr;
778 	t->parms.flags = p->flags;
779 	t->parms.hop_limit = p->hop_limit;
780 	t->parms.encap_limit = p->encap_limit;
781 	t->parms.flowinfo = p->flowinfo;
782 	t->parms.link = p->link;
783 	t->parms.proto = p->proto;
784 	t->parms.i_key = p->i_key;
785 	t->parms.o_key = p->o_key;
786 	t->parms.i_flags = p->i_flags;
787 	t->parms.o_flags = p->o_flags;
788 	t->parms.fwmark = p->fwmark;
789 	dst_cache_reset(&t->dst_cache);
790 	ip6gre_tnl_link_config(t, set_mtu);
791 	return 0;
792 }
793 
794 static void ip6gre_tnl_parm_from_user(struct __ip6_tnl_parm *p,
795 	const struct ip6_tnl_parm2 *u)
796 {
797 	p->laddr = u->laddr;
798 	p->raddr = u->raddr;
799 	p->flags = u->flags;
800 	p->hop_limit = u->hop_limit;
801 	p->encap_limit = u->encap_limit;
802 	p->flowinfo = u->flowinfo;
803 	p->link = u->link;
804 	p->i_key = u->i_key;
805 	p->o_key = u->o_key;
806 	p->i_flags = gre_flags_to_tnl_flags(u->i_flags);
807 	p->o_flags = gre_flags_to_tnl_flags(u->o_flags);
808 	memcpy(p->name, u->name, sizeof(u->name));
809 }
810 
811 static void ip6gre_tnl_parm_to_user(struct ip6_tnl_parm2 *u,
812 	const struct __ip6_tnl_parm *p)
813 {
814 	u->proto = IPPROTO_GRE;
815 	u->laddr = p->laddr;
816 	u->raddr = p->raddr;
817 	u->flags = p->flags;
818 	u->hop_limit = p->hop_limit;
819 	u->encap_limit = p->encap_limit;
820 	u->flowinfo = p->flowinfo;
821 	u->link = p->link;
822 	u->i_key = p->i_key;
823 	u->o_key = p->o_key;
824 	u->i_flags = gre_tnl_flags_to_gre_flags(p->i_flags);
825 	u->o_flags = gre_tnl_flags_to_gre_flags(p->o_flags);
826 	memcpy(u->name, p->name, sizeof(u->name));
827 }
828 
829 static int ip6gre_tunnel_ioctl(struct net_device *dev,
830 	struct ifreq *ifr, int cmd)
831 {
832 	int err = 0;
833 	struct ip6_tnl_parm2 p;
834 	struct __ip6_tnl_parm p1;
835 	struct ip6_tnl *t = netdev_priv(dev);
836 	struct net *net = t->net;
837 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
838 
839 	memset(&p1, 0, sizeof(p1));
840 
841 	switch (cmd) {
842 	case SIOCGETTUNNEL:
843 		if (dev == ign->fb_tunnel_dev) {
844 			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
845 				err = -EFAULT;
846 				break;
847 			}
848 			ip6gre_tnl_parm_from_user(&p1, &p);
849 			t = ip6gre_tunnel_locate(net, &p1, 0);
850 			if (!t)
851 				t = netdev_priv(dev);
852 		}
853 		memset(&p, 0, sizeof(p));
854 		ip6gre_tnl_parm_to_user(&p, &t->parms);
855 		if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
856 			err = -EFAULT;
857 		break;
858 
859 	case SIOCADDTUNNEL:
860 	case SIOCCHGTUNNEL:
861 		err = -EPERM;
862 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
863 			goto done;
864 
865 		err = -EFAULT;
866 		if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
867 			goto done;
868 
869 		err = -EINVAL;
870 		if ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING))
871 			goto done;
872 
873 		if (!(p.i_flags&GRE_KEY))
874 			p.i_key = 0;
875 		if (!(p.o_flags&GRE_KEY))
876 			p.o_key = 0;
877 
878 		ip6gre_tnl_parm_from_user(&p1, &p);
879 		t = ip6gre_tunnel_locate(net, &p1, cmd == SIOCADDTUNNEL);
880 
881 		if (dev != ign->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
882 			if (t) {
883 				if (t->dev != dev) {
884 					err = -EEXIST;
885 					break;
886 				}
887 			} else {
888 				t = netdev_priv(dev);
889 
890 				ip6gre_tunnel_unlink(ign, t);
891 				synchronize_net();
892 				ip6gre_tnl_change(t, &p1, 1);
893 				ip6gre_tunnel_link(ign, t);
894 				netdev_state_change(dev);
895 			}
896 		}
897 
898 		if (t) {
899 			err = 0;
900 
901 			memset(&p, 0, sizeof(p));
902 			ip6gre_tnl_parm_to_user(&p, &t->parms);
903 			if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
904 				err = -EFAULT;
905 		} else
906 			err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
907 		break;
908 
909 	case SIOCDELTUNNEL:
910 		err = -EPERM;
911 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
912 			goto done;
913 
914 		if (dev == ign->fb_tunnel_dev) {
915 			err = -EFAULT;
916 			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
917 				goto done;
918 			err = -ENOENT;
919 			ip6gre_tnl_parm_from_user(&p1, &p);
920 			t = ip6gre_tunnel_locate(net, &p1, 0);
921 			if (!t)
922 				goto done;
923 			err = -EPERM;
924 			if (t == netdev_priv(ign->fb_tunnel_dev))
925 				goto done;
926 			dev = t->dev;
927 		}
928 		unregister_netdevice(dev);
929 		err = 0;
930 		break;
931 
932 	default:
933 		err = -EINVAL;
934 	}
935 
936 done:
937 	return err;
938 }
939 
940 static int ip6gre_header(struct sk_buff *skb, struct net_device *dev,
941 			unsigned short type,
942 			const void *daddr, const void *saddr, unsigned int len)
943 {
944 	struct ip6_tnl *t = netdev_priv(dev);
945 	struct ipv6hdr *ipv6h = (struct ipv6hdr *)skb_push(skb, t->hlen);
946 	__be16 *p = (__be16 *)(ipv6h+1);
947 
948 	ip6_flow_hdr(ipv6h, 0,
949 		     ip6_make_flowlabel(dev_net(dev), skb,
950 					t->fl.u.ip6.flowlabel, true,
951 					&t->fl.u.ip6));
952 	ipv6h->hop_limit = t->parms.hop_limit;
953 	ipv6h->nexthdr = NEXTHDR_GRE;
954 	ipv6h->saddr = t->parms.laddr;
955 	ipv6h->daddr = t->parms.raddr;
956 
957 	p[0]		= t->parms.o_flags;
958 	p[1]		= htons(type);
959 
960 	/*
961 	 *	Set the source hardware address.
962 	 */
963 
964 	if (saddr)
965 		memcpy(&ipv6h->saddr, saddr, sizeof(struct in6_addr));
966 	if (daddr)
967 		memcpy(&ipv6h->daddr, daddr, sizeof(struct in6_addr));
968 	if (!ipv6_addr_any(&ipv6h->daddr))
969 		return t->hlen;
970 
971 	return -t->hlen;
972 }
973 
974 static const struct header_ops ip6gre_header_ops = {
975 	.create	= ip6gre_header,
976 };
977 
978 static const struct net_device_ops ip6gre_netdev_ops = {
979 	.ndo_init		= ip6gre_tunnel_init,
980 	.ndo_uninit		= ip6gre_tunnel_uninit,
981 	.ndo_start_xmit		= ip6gre_tunnel_xmit,
982 	.ndo_do_ioctl		= ip6gre_tunnel_ioctl,
983 	.ndo_change_mtu		= ip6_tnl_change_mtu,
984 	.ndo_get_stats64	= ip_tunnel_get_stats64,
985 	.ndo_get_iflink		= ip6_tnl_get_iflink,
986 };
987 
988 static void ip6gre_dev_free(struct net_device *dev)
989 {
990 	struct ip6_tnl *t = netdev_priv(dev);
991 
992 	dst_cache_destroy(&t->dst_cache);
993 	free_percpu(dev->tstats);
994 }
995 
996 static void ip6gre_tunnel_setup(struct net_device *dev)
997 {
998 	dev->netdev_ops = &ip6gre_netdev_ops;
999 	dev->needs_free_netdev = true;
1000 	dev->priv_destructor = ip6gre_dev_free;
1001 
1002 	dev->type = ARPHRD_IP6GRE;
1003 
1004 	dev->flags |= IFF_NOARP;
1005 	dev->addr_len = sizeof(struct in6_addr);
1006 	netif_keep_dst(dev);
1007 	/* This perm addr will be used as interface identifier by IPv6 */
1008 	dev->addr_assign_type = NET_ADDR_RANDOM;
1009 	eth_random_addr(dev->perm_addr);
1010 }
1011 
1012 static int ip6gre_tunnel_init_common(struct net_device *dev)
1013 {
1014 	struct ip6_tnl *tunnel;
1015 	int ret;
1016 	int t_hlen;
1017 
1018 	tunnel = netdev_priv(dev);
1019 
1020 	tunnel->dev = dev;
1021 	tunnel->net = dev_net(dev);
1022 	strcpy(tunnel->parms.name, dev->name);
1023 
1024 	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1025 	if (!dev->tstats)
1026 		return -ENOMEM;
1027 
1028 	ret = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL);
1029 	if (ret) {
1030 		free_percpu(dev->tstats);
1031 		dev->tstats = NULL;
1032 		return ret;
1033 	}
1034 
1035 	tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags);
1036 	tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen;
1037 	t_hlen = tunnel->hlen + sizeof(struct ipv6hdr);
1038 
1039 	dev->hard_header_len = LL_MAX_HEADER + t_hlen;
1040 	dev->mtu = ETH_DATA_LEN - t_hlen;
1041 	if (dev->type == ARPHRD_ETHER)
1042 		dev->mtu -= ETH_HLEN;
1043 	if (!(tunnel->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1044 		dev->mtu -= 8;
1045 
1046 	return 0;
1047 }
1048 
1049 static int ip6gre_tunnel_init(struct net_device *dev)
1050 {
1051 	struct ip6_tnl *tunnel;
1052 	int ret;
1053 
1054 	ret = ip6gre_tunnel_init_common(dev);
1055 	if (ret)
1056 		return ret;
1057 
1058 	tunnel = netdev_priv(dev);
1059 
1060 	memcpy(dev->dev_addr, &tunnel->parms.laddr, sizeof(struct in6_addr));
1061 	memcpy(dev->broadcast, &tunnel->parms.raddr, sizeof(struct in6_addr));
1062 
1063 	if (ipv6_addr_any(&tunnel->parms.raddr))
1064 		dev->header_ops = &ip6gre_header_ops;
1065 
1066 	return 0;
1067 }
1068 
1069 static void ip6gre_fb_tunnel_init(struct net_device *dev)
1070 {
1071 	struct ip6_tnl *tunnel = netdev_priv(dev);
1072 
1073 	tunnel->dev = dev;
1074 	tunnel->net = dev_net(dev);
1075 	strcpy(tunnel->parms.name, dev->name);
1076 
1077 	tunnel->hlen		= sizeof(struct ipv6hdr) + 4;
1078 
1079 	dev_hold(dev);
1080 }
1081 
1082 
1083 static struct inet6_protocol ip6gre_protocol __read_mostly = {
1084 	.handler     = gre_rcv,
1085 	.err_handler = ip6gre_err,
1086 	.flags       = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1087 };
1088 
1089 static void ip6gre_destroy_tunnels(struct net *net, struct list_head *head)
1090 {
1091 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1092 	struct net_device *dev, *aux;
1093 	int prio;
1094 
1095 	for_each_netdev_safe(net, dev, aux)
1096 		if (dev->rtnl_link_ops == &ip6gre_link_ops ||
1097 		    dev->rtnl_link_ops == &ip6gre_tap_ops)
1098 			unregister_netdevice_queue(dev, head);
1099 
1100 	for (prio = 0; prio < 4; prio++) {
1101 		int h;
1102 		for (h = 0; h < IP6_GRE_HASH_SIZE; h++) {
1103 			struct ip6_tnl *t;
1104 
1105 			t = rtnl_dereference(ign->tunnels[prio][h]);
1106 
1107 			while (t) {
1108 				/* If dev is in the same netns, it has already
1109 				 * been added to the list by the previous loop.
1110 				 */
1111 				if (!net_eq(dev_net(t->dev), net))
1112 					unregister_netdevice_queue(t->dev,
1113 								   head);
1114 				t = rtnl_dereference(t->next);
1115 			}
1116 		}
1117 	}
1118 }
1119 
1120 static int __net_init ip6gre_init_net(struct net *net)
1121 {
1122 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1123 	int err;
1124 
1125 	ign->fb_tunnel_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6gre0",
1126 					  NET_NAME_UNKNOWN,
1127 					  ip6gre_tunnel_setup);
1128 	if (!ign->fb_tunnel_dev) {
1129 		err = -ENOMEM;
1130 		goto err_alloc_dev;
1131 	}
1132 	dev_net_set(ign->fb_tunnel_dev, net);
1133 	/* FB netdevice is special: we have one, and only one per netns.
1134 	 * Allowing to move it to another netns is clearly unsafe.
1135 	 */
1136 	ign->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
1137 
1138 
1139 	ip6gre_fb_tunnel_init(ign->fb_tunnel_dev);
1140 	ign->fb_tunnel_dev->rtnl_link_ops = &ip6gre_link_ops;
1141 
1142 	err = register_netdev(ign->fb_tunnel_dev);
1143 	if (err)
1144 		goto err_reg_dev;
1145 
1146 	rcu_assign_pointer(ign->tunnels_wc[0],
1147 			   netdev_priv(ign->fb_tunnel_dev));
1148 	return 0;
1149 
1150 err_reg_dev:
1151 	free_netdev(ign->fb_tunnel_dev);
1152 err_alloc_dev:
1153 	return err;
1154 }
1155 
1156 static void __net_exit ip6gre_exit_net(struct net *net)
1157 {
1158 	LIST_HEAD(list);
1159 
1160 	rtnl_lock();
1161 	ip6gre_destroy_tunnels(net, &list);
1162 	unregister_netdevice_many(&list);
1163 	rtnl_unlock();
1164 }
1165 
1166 static struct pernet_operations ip6gre_net_ops = {
1167 	.init = ip6gre_init_net,
1168 	.exit = ip6gre_exit_net,
1169 	.id   = &ip6gre_net_id,
1170 	.size = sizeof(struct ip6gre_net),
1171 };
1172 
1173 static int ip6gre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[])
1174 {
1175 	__be16 flags;
1176 
1177 	if (!data)
1178 		return 0;
1179 
1180 	flags = 0;
1181 	if (data[IFLA_GRE_IFLAGS])
1182 		flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1183 	if (data[IFLA_GRE_OFLAGS])
1184 		flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1185 	if (flags & (GRE_VERSION|GRE_ROUTING))
1186 		return -EINVAL;
1187 
1188 	return 0;
1189 }
1190 
1191 static int ip6gre_tap_validate(struct nlattr *tb[], struct nlattr *data[])
1192 {
1193 	struct in6_addr daddr;
1194 
1195 	if (tb[IFLA_ADDRESS]) {
1196 		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1197 			return -EINVAL;
1198 		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1199 			return -EADDRNOTAVAIL;
1200 	}
1201 
1202 	if (!data)
1203 		goto out;
1204 
1205 	if (data[IFLA_GRE_REMOTE]) {
1206 		daddr = nla_get_in6_addr(data[IFLA_GRE_REMOTE]);
1207 		if (ipv6_addr_any(&daddr))
1208 			return -EINVAL;
1209 	}
1210 
1211 out:
1212 	return ip6gre_tunnel_validate(tb, data);
1213 }
1214 
1215 
1216 static void ip6gre_netlink_parms(struct nlattr *data[],
1217 				struct __ip6_tnl_parm *parms)
1218 {
1219 	memset(parms, 0, sizeof(*parms));
1220 
1221 	if (!data)
1222 		return;
1223 
1224 	if (data[IFLA_GRE_LINK])
1225 		parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
1226 
1227 	if (data[IFLA_GRE_IFLAGS])
1228 		parms->i_flags = gre_flags_to_tnl_flags(
1229 				nla_get_be16(data[IFLA_GRE_IFLAGS]));
1230 
1231 	if (data[IFLA_GRE_OFLAGS])
1232 		parms->o_flags = gre_flags_to_tnl_flags(
1233 				nla_get_be16(data[IFLA_GRE_OFLAGS]));
1234 
1235 	if (data[IFLA_GRE_IKEY])
1236 		parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
1237 
1238 	if (data[IFLA_GRE_OKEY])
1239 		parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
1240 
1241 	if (data[IFLA_GRE_LOCAL])
1242 		parms->laddr = nla_get_in6_addr(data[IFLA_GRE_LOCAL]);
1243 
1244 	if (data[IFLA_GRE_REMOTE])
1245 		parms->raddr = nla_get_in6_addr(data[IFLA_GRE_REMOTE]);
1246 
1247 	if (data[IFLA_GRE_TTL])
1248 		parms->hop_limit = nla_get_u8(data[IFLA_GRE_TTL]);
1249 
1250 	if (data[IFLA_GRE_ENCAP_LIMIT])
1251 		parms->encap_limit = nla_get_u8(data[IFLA_GRE_ENCAP_LIMIT]);
1252 
1253 	if (data[IFLA_GRE_FLOWINFO])
1254 		parms->flowinfo = nla_get_be32(data[IFLA_GRE_FLOWINFO]);
1255 
1256 	if (data[IFLA_GRE_FLAGS])
1257 		parms->flags = nla_get_u32(data[IFLA_GRE_FLAGS]);
1258 
1259 	if (data[IFLA_GRE_FWMARK])
1260 		parms->fwmark = nla_get_u32(data[IFLA_GRE_FWMARK]);
1261 }
1262 
1263 static int ip6gre_tap_init(struct net_device *dev)
1264 {
1265 	struct ip6_tnl *tunnel;
1266 	int ret;
1267 
1268 	ret = ip6gre_tunnel_init_common(dev);
1269 	if (ret)
1270 		return ret;
1271 
1272 	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1273 
1274 	tunnel = netdev_priv(dev);
1275 
1276 	ip6gre_tnl_link_config(tunnel, 1);
1277 
1278 	return 0;
1279 }
1280 
1281 static const struct net_device_ops ip6gre_tap_netdev_ops = {
1282 	.ndo_init = ip6gre_tap_init,
1283 	.ndo_uninit = ip6gre_tunnel_uninit,
1284 	.ndo_start_xmit = ip6gre_tunnel_xmit,
1285 	.ndo_set_mac_address = eth_mac_addr,
1286 	.ndo_validate_addr = eth_validate_addr,
1287 	.ndo_change_mtu = ip6_tnl_change_mtu,
1288 	.ndo_get_stats64 = ip_tunnel_get_stats64,
1289 	.ndo_get_iflink = ip6_tnl_get_iflink,
1290 };
1291 
1292 #define GRE6_FEATURES (NETIF_F_SG |		\
1293 		       NETIF_F_FRAGLIST |	\
1294 		       NETIF_F_HIGHDMA |		\
1295 		       NETIF_F_HW_CSUM)
1296 
1297 static void ip6gre_tap_setup(struct net_device *dev)
1298 {
1299 
1300 	ether_setup(dev);
1301 
1302 	dev->netdev_ops = &ip6gre_tap_netdev_ops;
1303 	dev->needs_free_netdev = true;
1304 	dev->priv_destructor = ip6gre_dev_free;
1305 
1306 	dev->features |= NETIF_F_NETNS_LOCAL;
1307 	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1308 	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1309 }
1310 
1311 static bool ip6gre_netlink_encap_parms(struct nlattr *data[],
1312 				       struct ip_tunnel_encap *ipencap)
1313 {
1314 	bool ret = false;
1315 
1316 	memset(ipencap, 0, sizeof(*ipencap));
1317 
1318 	if (!data)
1319 		return ret;
1320 
1321 	if (data[IFLA_GRE_ENCAP_TYPE]) {
1322 		ret = true;
1323 		ipencap->type = nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]);
1324 	}
1325 
1326 	if (data[IFLA_GRE_ENCAP_FLAGS]) {
1327 		ret = true;
1328 		ipencap->flags = nla_get_u16(data[IFLA_GRE_ENCAP_FLAGS]);
1329 	}
1330 
1331 	if (data[IFLA_GRE_ENCAP_SPORT]) {
1332 		ret = true;
1333 		ipencap->sport = nla_get_be16(data[IFLA_GRE_ENCAP_SPORT]);
1334 	}
1335 
1336 	if (data[IFLA_GRE_ENCAP_DPORT]) {
1337 		ret = true;
1338 		ipencap->dport = nla_get_be16(data[IFLA_GRE_ENCAP_DPORT]);
1339 	}
1340 
1341 	return ret;
1342 }
1343 
1344 static int ip6gre_newlink(struct net *src_net, struct net_device *dev,
1345 	struct nlattr *tb[], struct nlattr *data[])
1346 {
1347 	struct ip6_tnl *nt;
1348 	struct net *net = dev_net(dev);
1349 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1350 	struct ip_tunnel_encap ipencap;
1351 	int err;
1352 
1353 	nt = netdev_priv(dev);
1354 
1355 	if (ip6gre_netlink_encap_parms(data, &ipencap)) {
1356 		int err = ip6_tnl_encap_setup(nt, &ipencap);
1357 
1358 		if (err < 0)
1359 			return err;
1360 	}
1361 
1362 	ip6gre_netlink_parms(data, &nt->parms);
1363 
1364 	if (ip6gre_tunnel_find(net, &nt->parms, dev->type))
1365 		return -EEXIST;
1366 
1367 	if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
1368 		eth_hw_addr_random(dev);
1369 
1370 	nt->dev = dev;
1371 	nt->net = dev_net(dev);
1372 	ip6gre_tnl_link_config(nt, !tb[IFLA_MTU]);
1373 
1374 	dev->features		|= GRE6_FEATURES;
1375 	dev->hw_features	|= GRE6_FEATURES;
1376 
1377 	if (!(nt->parms.o_flags & TUNNEL_SEQ)) {
1378 		/* TCP offload with GRE SEQ is not supported, nor
1379 		 * can we support 2 levels of outer headers requiring
1380 		 * an update.
1381 		 */
1382 		if (!(nt->parms.o_flags & TUNNEL_CSUM) ||
1383 		    (nt->encap.type == TUNNEL_ENCAP_NONE)) {
1384 			dev->features    |= NETIF_F_GSO_SOFTWARE;
1385 			dev->hw_features |= NETIF_F_GSO_SOFTWARE;
1386 		}
1387 
1388 		/* Can use a lockless transmit, unless we generate
1389 		 * output sequences
1390 		 */
1391 		dev->features |= NETIF_F_LLTX;
1392 	}
1393 
1394 	err = register_netdevice(dev);
1395 	if (err)
1396 		goto out;
1397 
1398 	dev_hold(dev);
1399 	ip6gre_tunnel_link(ign, nt);
1400 
1401 out:
1402 	return err;
1403 }
1404 
1405 static int ip6gre_changelink(struct net_device *dev, struct nlattr *tb[],
1406 			    struct nlattr *data[])
1407 {
1408 	struct ip6_tnl *t, *nt = netdev_priv(dev);
1409 	struct net *net = nt->net;
1410 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1411 	struct __ip6_tnl_parm p;
1412 	struct ip_tunnel_encap ipencap;
1413 
1414 	if (dev == ign->fb_tunnel_dev)
1415 		return -EINVAL;
1416 
1417 	if (ip6gre_netlink_encap_parms(data, &ipencap)) {
1418 		int err = ip6_tnl_encap_setup(nt, &ipencap);
1419 
1420 		if (err < 0)
1421 			return err;
1422 	}
1423 
1424 	ip6gre_netlink_parms(data, &p);
1425 
1426 	t = ip6gre_tunnel_locate(net, &p, 0);
1427 
1428 	if (t) {
1429 		if (t->dev != dev)
1430 			return -EEXIST;
1431 	} else {
1432 		t = nt;
1433 	}
1434 
1435 	ip6gre_tunnel_unlink(ign, t);
1436 	ip6gre_tnl_change(t, &p, !tb[IFLA_MTU]);
1437 	ip6gre_tunnel_link(ign, t);
1438 	return 0;
1439 }
1440 
1441 static void ip6gre_dellink(struct net_device *dev, struct list_head *head)
1442 {
1443 	struct net *net = dev_net(dev);
1444 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1445 
1446 	if (dev != ign->fb_tunnel_dev)
1447 		unregister_netdevice_queue(dev, head);
1448 }
1449 
1450 static size_t ip6gre_get_size(const struct net_device *dev)
1451 {
1452 	return
1453 		/* IFLA_GRE_LINK */
1454 		nla_total_size(4) +
1455 		/* IFLA_GRE_IFLAGS */
1456 		nla_total_size(2) +
1457 		/* IFLA_GRE_OFLAGS */
1458 		nla_total_size(2) +
1459 		/* IFLA_GRE_IKEY */
1460 		nla_total_size(4) +
1461 		/* IFLA_GRE_OKEY */
1462 		nla_total_size(4) +
1463 		/* IFLA_GRE_LOCAL */
1464 		nla_total_size(sizeof(struct in6_addr)) +
1465 		/* IFLA_GRE_REMOTE */
1466 		nla_total_size(sizeof(struct in6_addr)) +
1467 		/* IFLA_GRE_TTL */
1468 		nla_total_size(1) +
1469 		/* IFLA_GRE_ENCAP_LIMIT */
1470 		nla_total_size(1) +
1471 		/* IFLA_GRE_FLOWINFO */
1472 		nla_total_size(4) +
1473 		/* IFLA_GRE_FLAGS */
1474 		nla_total_size(4) +
1475 		/* IFLA_GRE_ENCAP_TYPE */
1476 		nla_total_size(2) +
1477 		/* IFLA_GRE_ENCAP_FLAGS */
1478 		nla_total_size(2) +
1479 		/* IFLA_GRE_ENCAP_SPORT */
1480 		nla_total_size(2) +
1481 		/* IFLA_GRE_ENCAP_DPORT */
1482 		nla_total_size(2) +
1483 		/* IFLA_GRE_FWMARK */
1484 		nla_total_size(4) +
1485 		0;
1486 }
1487 
1488 static int ip6gre_fill_info(struct sk_buff *skb, const struct net_device *dev)
1489 {
1490 	struct ip6_tnl *t = netdev_priv(dev);
1491 	struct __ip6_tnl_parm *p = &t->parms;
1492 
1493 	if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
1494 	    nla_put_be16(skb, IFLA_GRE_IFLAGS,
1495 			 gre_tnl_flags_to_gre_flags(p->i_flags)) ||
1496 	    nla_put_be16(skb, IFLA_GRE_OFLAGS,
1497 			 gre_tnl_flags_to_gre_flags(p->o_flags)) ||
1498 	    nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
1499 	    nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
1500 	    nla_put_in6_addr(skb, IFLA_GRE_LOCAL, &p->laddr) ||
1501 	    nla_put_in6_addr(skb, IFLA_GRE_REMOTE, &p->raddr) ||
1502 	    nla_put_u8(skb, IFLA_GRE_TTL, p->hop_limit) ||
1503 	    nla_put_u8(skb, IFLA_GRE_ENCAP_LIMIT, p->encap_limit) ||
1504 	    nla_put_be32(skb, IFLA_GRE_FLOWINFO, p->flowinfo) ||
1505 	    nla_put_u32(skb, IFLA_GRE_FLAGS, p->flags) ||
1506 	    nla_put_u32(skb, IFLA_GRE_FWMARK, p->fwmark))
1507 		goto nla_put_failure;
1508 
1509 	if (nla_put_u16(skb, IFLA_GRE_ENCAP_TYPE,
1510 			t->encap.type) ||
1511 	    nla_put_be16(skb, IFLA_GRE_ENCAP_SPORT,
1512 			 t->encap.sport) ||
1513 	    nla_put_be16(skb, IFLA_GRE_ENCAP_DPORT,
1514 			 t->encap.dport) ||
1515 	    nla_put_u16(skb, IFLA_GRE_ENCAP_FLAGS,
1516 			t->encap.flags))
1517 		goto nla_put_failure;
1518 
1519 	return 0;
1520 
1521 nla_put_failure:
1522 	return -EMSGSIZE;
1523 }
1524 
1525 static const struct nla_policy ip6gre_policy[IFLA_GRE_MAX + 1] = {
1526 	[IFLA_GRE_LINK]        = { .type = NLA_U32 },
1527 	[IFLA_GRE_IFLAGS]      = { .type = NLA_U16 },
1528 	[IFLA_GRE_OFLAGS]      = { .type = NLA_U16 },
1529 	[IFLA_GRE_IKEY]        = { .type = NLA_U32 },
1530 	[IFLA_GRE_OKEY]        = { .type = NLA_U32 },
1531 	[IFLA_GRE_LOCAL]       = { .len = FIELD_SIZEOF(struct ipv6hdr, saddr) },
1532 	[IFLA_GRE_REMOTE]      = { .len = FIELD_SIZEOF(struct ipv6hdr, daddr) },
1533 	[IFLA_GRE_TTL]         = { .type = NLA_U8 },
1534 	[IFLA_GRE_ENCAP_LIMIT] = { .type = NLA_U8 },
1535 	[IFLA_GRE_FLOWINFO]    = { .type = NLA_U32 },
1536 	[IFLA_GRE_FLAGS]       = { .type = NLA_U32 },
1537 	[IFLA_GRE_ENCAP_TYPE]   = { .type = NLA_U16 },
1538 	[IFLA_GRE_ENCAP_FLAGS]  = { .type = NLA_U16 },
1539 	[IFLA_GRE_ENCAP_SPORT]  = { .type = NLA_U16 },
1540 	[IFLA_GRE_ENCAP_DPORT]  = { .type = NLA_U16 },
1541 	[IFLA_GRE_FWMARK]       = { .type = NLA_U32 },
1542 };
1543 
1544 static struct rtnl_link_ops ip6gre_link_ops __read_mostly = {
1545 	.kind		= "ip6gre",
1546 	.maxtype	= IFLA_GRE_MAX,
1547 	.policy		= ip6gre_policy,
1548 	.priv_size	= sizeof(struct ip6_tnl),
1549 	.setup		= ip6gre_tunnel_setup,
1550 	.validate	= ip6gre_tunnel_validate,
1551 	.newlink	= ip6gre_newlink,
1552 	.changelink	= ip6gre_changelink,
1553 	.dellink	= ip6gre_dellink,
1554 	.get_size	= ip6gre_get_size,
1555 	.fill_info	= ip6gre_fill_info,
1556 	.get_link_net	= ip6_tnl_get_link_net,
1557 };
1558 
1559 static struct rtnl_link_ops ip6gre_tap_ops __read_mostly = {
1560 	.kind		= "ip6gretap",
1561 	.maxtype	= IFLA_GRE_MAX,
1562 	.policy		= ip6gre_policy,
1563 	.priv_size	= sizeof(struct ip6_tnl),
1564 	.setup		= ip6gre_tap_setup,
1565 	.validate	= ip6gre_tap_validate,
1566 	.newlink	= ip6gre_newlink,
1567 	.changelink	= ip6gre_changelink,
1568 	.get_size	= ip6gre_get_size,
1569 	.fill_info	= ip6gre_fill_info,
1570 	.get_link_net	= ip6_tnl_get_link_net,
1571 };
1572 
1573 /*
1574  *	And now the modules code and kernel interface.
1575  */
1576 
1577 static int __init ip6gre_init(void)
1578 {
1579 	int err;
1580 
1581 	pr_info("GRE over IPv6 tunneling driver\n");
1582 
1583 	err = register_pernet_device(&ip6gre_net_ops);
1584 	if (err < 0)
1585 		return err;
1586 
1587 	err = inet6_add_protocol(&ip6gre_protocol, IPPROTO_GRE);
1588 	if (err < 0) {
1589 		pr_info("%s: can't add protocol\n", __func__);
1590 		goto add_proto_failed;
1591 	}
1592 
1593 	err = rtnl_link_register(&ip6gre_link_ops);
1594 	if (err < 0)
1595 		goto rtnl_link_failed;
1596 
1597 	err = rtnl_link_register(&ip6gre_tap_ops);
1598 	if (err < 0)
1599 		goto tap_ops_failed;
1600 
1601 out:
1602 	return err;
1603 
1604 tap_ops_failed:
1605 	rtnl_link_unregister(&ip6gre_link_ops);
1606 rtnl_link_failed:
1607 	inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
1608 add_proto_failed:
1609 	unregister_pernet_device(&ip6gre_net_ops);
1610 	goto out;
1611 }
1612 
1613 static void __exit ip6gre_fini(void)
1614 {
1615 	rtnl_link_unregister(&ip6gre_tap_ops);
1616 	rtnl_link_unregister(&ip6gre_link_ops);
1617 	inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
1618 	unregister_pernet_device(&ip6gre_net_ops);
1619 }
1620 
1621 module_init(ip6gre_init);
1622 module_exit(ip6gre_fini);
1623 MODULE_LICENSE("GPL");
1624 MODULE_AUTHOR("D. Kozlov (xeb@mail.ru)");
1625 MODULE_DESCRIPTION("GRE over IPv6 tunneling device");
1626 MODULE_ALIAS_RTNL_LINK("ip6gre");
1627 MODULE_ALIAS_RTNL_LINK("ip6gretap");
1628 MODULE_ALIAS_NETDEV("ip6gre0");
1629