xref: /openbmc/linux/net/ipv6/ip6_gre.c (revision 6dfcd296)
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 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 ipv6hdr *ipv6h = (const struct ipv6hdr *)skb->data;
373 	__be16 *p = (__be16 *)(skb->data + offset);
374 	int grehlen = offset + 4;
375 	struct ip6_tnl *t;
376 	__be16 flags;
377 
378 	flags = p[0];
379 	if (flags&(GRE_CSUM|GRE_KEY|GRE_SEQ|GRE_ROUTING|GRE_VERSION)) {
380 		if (flags&(GRE_VERSION|GRE_ROUTING))
381 			return;
382 		if (flags&GRE_KEY) {
383 			grehlen += 4;
384 			if (flags&GRE_CSUM)
385 				grehlen += 4;
386 		}
387 	}
388 
389 	/* If only 8 bytes returned, keyed message will be dropped here */
390 	if (!pskb_may_pull(skb, grehlen))
391 		return;
392 	ipv6h = (const struct ipv6hdr *)skb->data;
393 	p = (__be16 *)(skb->data + offset);
394 
395 	t = ip6gre_tunnel_lookup(skb->dev, &ipv6h->daddr, &ipv6h->saddr,
396 				flags & GRE_KEY ?
397 				*(((__be32 *)p) + (grehlen / 4) - 1) : 0,
398 				p[1]);
399 	if (!t)
400 		return;
401 
402 	switch (type) {
403 		__u32 teli;
404 		struct ipv6_tlv_tnl_enc_lim *tel;
405 		__u32 mtu;
406 	case ICMPV6_DEST_UNREACH:
407 		net_dbg_ratelimited("%s: Path to destination invalid or inactive!\n",
408 				    t->parms.name);
409 		break;
410 	case ICMPV6_TIME_EXCEED:
411 		if (code == ICMPV6_EXC_HOPLIMIT) {
412 			net_dbg_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
413 					    t->parms.name);
414 		}
415 		break;
416 	case ICMPV6_PARAMPROB:
417 		teli = 0;
418 		if (code == ICMPV6_HDR_FIELD)
419 			teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
420 
421 		if (teli && teli == be32_to_cpu(info) - 2) {
422 			tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
423 			if (tel->encap_limit == 0) {
424 				net_dbg_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
425 						    t->parms.name);
426 			}
427 		} else {
428 			net_dbg_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
429 					    t->parms.name);
430 		}
431 		break;
432 	case ICMPV6_PKT_TOOBIG:
433 		mtu = be32_to_cpu(info) - offset;
434 		if (mtu < IPV6_MIN_MTU)
435 			mtu = IPV6_MIN_MTU;
436 		t->dev->mtu = mtu;
437 		break;
438 	}
439 
440 	if (time_before(jiffies, t->err_time + IP6TUNNEL_ERR_TIMEO))
441 		t->err_count++;
442 	else
443 		t->err_count = 1;
444 	t->err_time = jiffies;
445 }
446 
447 static int ip6gre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi)
448 {
449 	const struct ipv6hdr *ipv6h;
450 	struct ip6_tnl *tunnel;
451 
452 	ipv6h = ipv6_hdr(skb);
453 	tunnel = ip6gre_tunnel_lookup(skb->dev,
454 				      &ipv6h->saddr, &ipv6h->daddr, tpi->key,
455 				      tpi->proto);
456 	if (tunnel) {
457 		ip6_tnl_rcv(tunnel, skb, tpi, NULL, false);
458 
459 		return PACKET_RCVD;
460 	}
461 
462 	return PACKET_REJECT;
463 }
464 
465 static int gre_rcv(struct sk_buff *skb)
466 {
467 	struct tnl_ptk_info tpi;
468 	bool csum_err = false;
469 	int hdr_len;
470 
471 	hdr_len = gre_parse_header(skb, &tpi, &csum_err, htons(ETH_P_IPV6), 0);
472 	if (hdr_len < 0)
473 		goto drop;
474 
475 	if (iptunnel_pull_header(skb, hdr_len, tpi.proto, false))
476 		goto drop;
477 
478 	if (ip6gre_rcv(skb, &tpi) == PACKET_RCVD)
479 		return 0;
480 
481 	icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
482 drop:
483 	kfree_skb(skb);
484 	return 0;
485 }
486 
487 struct ipv6_tel_txoption {
488 	struct ipv6_txoptions ops;
489 	__u8 dst_opt[8];
490 };
491 
492 static int gre_handle_offloads(struct sk_buff *skb, bool csum)
493 {
494 	return iptunnel_handle_offloads(skb,
495 					csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE);
496 }
497 
498 static netdev_tx_t __gre6_xmit(struct sk_buff *skb,
499 			       struct net_device *dev, __u8 dsfield,
500 			       struct flowi6 *fl6, int encap_limit,
501 			       __u32 *pmtu, __be16 proto)
502 {
503 	struct ip6_tnl *tunnel = netdev_priv(dev);
504 	__be16 protocol = (dev->type == ARPHRD_ETHER) ?
505 			  htons(ETH_P_TEB) : proto;
506 
507 	if (dev->type == ARPHRD_ETHER)
508 		IPCB(skb)->flags = 0;
509 
510 	if (dev->header_ops && dev->type == ARPHRD_IP6GRE)
511 		fl6->daddr = ((struct ipv6hdr *)skb->data)->daddr;
512 	else
513 		fl6->daddr = tunnel->parms.raddr;
514 
515 	if (tunnel->parms.o_flags & TUNNEL_SEQ)
516 		tunnel->o_seqno++;
517 
518 	/* Push GRE header. */
519 	gre_build_header(skb, tunnel->tun_hlen, tunnel->parms.o_flags,
520 			 protocol, tunnel->parms.o_key, htonl(tunnel->o_seqno));
521 
522 	return ip6_tnl_xmit(skb, dev, dsfield, fl6, encap_limit, pmtu,
523 			    NEXTHDR_GRE);
524 }
525 
526 static inline int ip6gre_xmit_ipv4(struct sk_buff *skb, struct net_device *dev)
527 {
528 	struct ip6_tnl *t = netdev_priv(dev);
529 	const struct iphdr  *iph = ip_hdr(skb);
530 	int encap_limit = -1;
531 	struct flowi6 fl6;
532 	__u8 dsfield;
533 	__u32 mtu;
534 	int err;
535 
536 	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
537 
538 	if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
539 		encap_limit = t->parms.encap_limit;
540 
541 	memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
542 
543 	dsfield = ipv4_get_dsfield(iph);
544 
545 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
546 		fl6.flowlabel |= htonl((__u32)iph->tos << IPV6_TCLASS_SHIFT)
547 					  & IPV6_TCLASS_MASK;
548 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
549 		fl6.flowi6_mark = skb->mark;
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 	if (offset > 0) {
584 		struct ipv6_tlv_tnl_enc_lim *tel;
585 		tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset];
586 		if (tel->encap_limit == 0) {
587 			icmpv6_send(skb, ICMPV6_PARAMPROB,
588 				    ICMPV6_HDR_FIELD, offset + 2);
589 			return -1;
590 		}
591 		encap_limit = tel->encap_limit - 1;
592 	} else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
593 		encap_limit = t->parms.encap_limit;
594 
595 	memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
596 
597 	dsfield = ipv6_get_dsfield(ipv6h);
598 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
599 		fl6.flowlabel |= (*(__be32 *) ipv6h & IPV6_TCLASS_MASK);
600 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
601 		fl6.flowlabel |= ip6_flowlabel(ipv6h);
602 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
603 		fl6.flowi6_mark = skb->mark;
604 
605 	if (gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM)))
606 		return -1;
607 
608 	err = __gre6_xmit(skb, dev, dsfield, &fl6, encap_limit,
609 			  &mtu, skb->protocol);
610 	if (err != 0) {
611 		if (err == -EMSGSIZE)
612 			icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
613 		return -1;
614 	}
615 
616 	return 0;
617 }
618 
619 /**
620  * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
621  *   @t: the outgoing tunnel device
622  *   @hdr: IPv6 header from the incoming packet
623  *
624  * Description:
625  *   Avoid trivial tunneling loop by checking that tunnel exit-point
626  *   doesn't match source of incoming packet.
627  *
628  * Return:
629  *   1 if conflict,
630  *   0 else
631  **/
632 
633 static inline bool ip6gre_tnl_addr_conflict(const struct ip6_tnl *t,
634 	const struct ipv6hdr *hdr)
635 {
636 	return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
637 }
638 
639 static int ip6gre_xmit_other(struct sk_buff *skb, struct net_device *dev)
640 {
641 	struct ip6_tnl *t = netdev_priv(dev);
642 	int encap_limit = -1;
643 	struct flowi6 fl6;
644 	__u32 mtu;
645 	int err;
646 
647 	if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
648 		encap_limit = t->parms.encap_limit;
649 
650 	memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
651 
652 	err = gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM));
653 	if (err)
654 		return err;
655 
656 	err = __gre6_xmit(skb, dev, 0, &fl6, encap_limit, &mtu, skb->protocol);
657 
658 	return err;
659 }
660 
661 static netdev_tx_t ip6gre_tunnel_xmit(struct sk_buff *skb,
662 	struct net_device *dev)
663 {
664 	struct ip6_tnl *t = netdev_priv(dev);
665 	struct net_device_stats *stats = &t->dev->stats;
666 	int ret;
667 
668 	if (!ip6_tnl_xmit_ctl(t, &t->parms.laddr, &t->parms.raddr))
669 		goto tx_err;
670 
671 	switch (skb->protocol) {
672 	case htons(ETH_P_IP):
673 		ret = ip6gre_xmit_ipv4(skb, dev);
674 		break;
675 	case htons(ETH_P_IPV6):
676 		ret = ip6gre_xmit_ipv6(skb, dev);
677 		break;
678 	default:
679 		ret = ip6gre_xmit_other(skb, dev);
680 		break;
681 	}
682 
683 	if (ret < 0)
684 		goto tx_err;
685 
686 	return NETDEV_TX_OK;
687 
688 tx_err:
689 	stats->tx_errors++;
690 	stats->tx_dropped++;
691 	kfree_skb(skb);
692 	return NETDEV_TX_OK;
693 }
694 
695 static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu)
696 {
697 	struct net_device *dev = t->dev;
698 	struct __ip6_tnl_parm *p = &t->parms;
699 	struct flowi6 *fl6 = &t->fl.u.ip6;
700 	int t_hlen;
701 
702 	if (dev->type != ARPHRD_ETHER) {
703 		memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
704 		memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
705 	}
706 
707 	/* Set up flowi template */
708 	fl6->saddr = p->laddr;
709 	fl6->daddr = p->raddr;
710 	fl6->flowi6_oif = p->link;
711 	fl6->flowlabel = 0;
712 	fl6->flowi6_proto = IPPROTO_GRE;
713 
714 	if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
715 		fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
716 	if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
717 		fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
718 
719 	p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
720 	p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
721 
722 	if (p->flags&IP6_TNL_F_CAP_XMIT &&
723 			p->flags&IP6_TNL_F_CAP_RCV && dev->type != ARPHRD_ETHER)
724 		dev->flags |= IFF_POINTOPOINT;
725 	else
726 		dev->flags &= ~IFF_POINTOPOINT;
727 
728 	t->tun_hlen = gre_calc_hlen(t->parms.o_flags);
729 
730 	t->hlen = t->encap_hlen + t->tun_hlen;
731 
732 	t_hlen = t->hlen + sizeof(struct ipv6hdr);
733 
734 	if (p->flags & IP6_TNL_F_CAP_XMIT) {
735 		int strict = (ipv6_addr_type(&p->raddr) &
736 			      (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
737 
738 		struct rt6_info *rt = rt6_lookup(t->net,
739 						 &p->raddr, &p->laddr,
740 						 p->link, strict);
741 
742 		if (!rt)
743 			return;
744 
745 		if (rt->dst.dev) {
746 			dev->hard_header_len = rt->dst.dev->hard_header_len +
747 					       t_hlen;
748 
749 			if (set_mtu) {
750 				dev->mtu = rt->dst.dev->mtu - t_hlen;
751 				if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
752 					dev->mtu -= 8;
753 				if (dev->type == ARPHRD_ETHER)
754 					dev->mtu -= ETH_HLEN;
755 
756 				if (dev->mtu < IPV6_MIN_MTU)
757 					dev->mtu = IPV6_MIN_MTU;
758 			}
759 		}
760 		ip6_rt_put(rt);
761 	}
762 }
763 
764 static int ip6gre_tnl_change(struct ip6_tnl *t,
765 	const struct __ip6_tnl_parm *p, int set_mtu)
766 {
767 	t->parms.laddr = p->laddr;
768 	t->parms.raddr = p->raddr;
769 	t->parms.flags = p->flags;
770 	t->parms.hop_limit = p->hop_limit;
771 	t->parms.encap_limit = p->encap_limit;
772 	t->parms.flowinfo = p->flowinfo;
773 	t->parms.link = p->link;
774 	t->parms.proto = p->proto;
775 	t->parms.i_key = p->i_key;
776 	t->parms.o_key = p->o_key;
777 	t->parms.i_flags = p->i_flags;
778 	t->parms.o_flags = p->o_flags;
779 	dst_cache_reset(&t->dst_cache);
780 	ip6gre_tnl_link_config(t, set_mtu);
781 	return 0;
782 }
783 
784 static void ip6gre_tnl_parm_from_user(struct __ip6_tnl_parm *p,
785 	const struct ip6_tnl_parm2 *u)
786 {
787 	p->laddr = u->laddr;
788 	p->raddr = u->raddr;
789 	p->flags = u->flags;
790 	p->hop_limit = u->hop_limit;
791 	p->encap_limit = u->encap_limit;
792 	p->flowinfo = u->flowinfo;
793 	p->link = u->link;
794 	p->i_key = u->i_key;
795 	p->o_key = u->o_key;
796 	p->i_flags = gre_flags_to_tnl_flags(u->i_flags);
797 	p->o_flags = gre_flags_to_tnl_flags(u->o_flags);
798 	memcpy(p->name, u->name, sizeof(u->name));
799 }
800 
801 static void ip6gre_tnl_parm_to_user(struct ip6_tnl_parm2 *u,
802 	const struct __ip6_tnl_parm *p)
803 {
804 	u->proto = IPPROTO_GRE;
805 	u->laddr = p->laddr;
806 	u->raddr = p->raddr;
807 	u->flags = p->flags;
808 	u->hop_limit = p->hop_limit;
809 	u->encap_limit = p->encap_limit;
810 	u->flowinfo = p->flowinfo;
811 	u->link = p->link;
812 	u->i_key = p->i_key;
813 	u->o_key = p->o_key;
814 	u->i_flags = gre_tnl_flags_to_gre_flags(p->i_flags);
815 	u->o_flags = gre_tnl_flags_to_gre_flags(p->o_flags);
816 	memcpy(u->name, p->name, sizeof(u->name));
817 }
818 
819 static int ip6gre_tunnel_ioctl(struct net_device *dev,
820 	struct ifreq *ifr, int cmd)
821 {
822 	int err = 0;
823 	struct ip6_tnl_parm2 p;
824 	struct __ip6_tnl_parm p1;
825 	struct ip6_tnl *t = netdev_priv(dev);
826 	struct net *net = t->net;
827 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
828 
829 	memset(&p1, 0, sizeof(p1));
830 
831 	switch (cmd) {
832 	case SIOCGETTUNNEL:
833 		if (dev == ign->fb_tunnel_dev) {
834 			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
835 				err = -EFAULT;
836 				break;
837 			}
838 			ip6gre_tnl_parm_from_user(&p1, &p);
839 			t = ip6gre_tunnel_locate(net, &p1, 0);
840 			if (!t)
841 				t = netdev_priv(dev);
842 		}
843 		memset(&p, 0, sizeof(p));
844 		ip6gre_tnl_parm_to_user(&p, &t->parms);
845 		if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
846 			err = -EFAULT;
847 		break;
848 
849 	case SIOCADDTUNNEL:
850 	case SIOCCHGTUNNEL:
851 		err = -EPERM;
852 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
853 			goto done;
854 
855 		err = -EFAULT;
856 		if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
857 			goto done;
858 
859 		err = -EINVAL;
860 		if ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING))
861 			goto done;
862 
863 		if (!(p.i_flags&GRE_KEY))
864 			p.i_key = 0;
865 		if (!(p.o_flags&GRE_KEY))
866 			p.o_key = 0;
867 
868 		ip6gre_tnl_parm_from_user(&p1, &p);
869 		t = ip6gre_tunnel_locate(net, &p1, cmd == SIOCADDTUNNEL);
870 
871 		if (dev != ign->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
872 			if (t) {
873 				if (t->dev != dev) {
874 					err = -EEXIST;
875 					break;
876 				}
877 			} else {
878 				t = netdev_priv(dev);
879 
880 				ip6gre_tunnel_unlink(ign, t);
881 				synchronize_net();
882 				ip6gre_tnl_change(t, &p1, 1);
883 				ip6gre_tunnel_link(ign, t);
884 				netdev_state_change(dev);
885 			}
886 		}
887 
888 		if (t) {
889 			err = 0;
890 
891 			memset(&p, 0, sizeof(p));
892 			ip6gre_tnl_parm_to_user(&p, &t->parms);
893 			if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
894 				err = -EFAULT;
895 		} else
896 			err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
897 		break;
898 
899 	case SIOCDELTUNNEL:
900 		err = -EPERM;
901 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
902 			goto done;
903 
904 		if (dev == ign->fb_tunnel_dev) {
905 			err = -EFAULT;
906 			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
907 				goto done;
908 			err = -ENOENT;
909 			ip6gre_tnl_parm_from_user(&p1, &p);
910 			t = ip6gre_tunnel_locate(net, &p1, 0);
911 			if (!t)
912 				goto done;
913 			err = -EPERM;
914 			if (t == netdev_priv(ign->fb_tunnel_dev))
915 				goto done;
916 			dev = t->dev;
917 		}
918 		unregister_netdevice(dev);
919 		err = 0;
920 		break;
921 
922 	default:
923 		err = -EINVAL;
924 	}
925 
926 done:
927 	return err;
928 }
929 
930 static int ip6gre_header(struct sk_buff *skb, struct net_device *dev,
931 			unsigned short type,
932 			const void *daddr, const void *saddr, unsigned int len)
933 {
934 	struct ip6_tnl *t = netdev_priv(dev);
935 	struct ipv6hdr *ipv6h = (struct ipv6hdr *)skb_push(skb, t->hlen);
936 	__be16 *p = (__be16 *)(ipv6h+1);
937 
938 	ip6_flow_hdr(ipv6h, 0,
939 		     ip6_make_flowlabel(dev_net(dev), skb,
940 					t->fl.u.ip6.flowlabel, true,
941 					&t->fl.u.ip6));
942 	ipv6h->hop_limit = t->parms.hop_limit;
943 	ipv6h->nexthdr = NEXTHDR_GRE;
944 	ipv6h->saddr = t->parms.laddr;
945 	ipv6h->daddr = t->parms.raddr;
946 
947 	p[0]		= t->parms.o_flags;
948 	p[1]		= htons(type);
949 
950 	/*
951 	 *	Set the source hardware address.
952 	 */
953 
954 	if (saddr)
955 		memcpy(&ipv6h->saddr, saddr, sizeof(struct in6_addr));
956 	if (daddr)
957 		memcpy(&ipv6h->daddr, daddr, sizeof(struct in6_addr));
958 	if (!ipv6_addr_any(&ipv6h->daddr))
959 		return t->hlen;
960 
961 	return -t->hlen;
962 }
963 
964 static const struct header_ops ip6gre_header_ops = {
965 	.create	= ip6gre_header,
966 };
967 
968 static const struct net_device_ops ip6gre_netdev_ops = {
969 	.ndo_init		= ip6gre_tunnel_init,
970 	.ndo_uninit		= ip6gre_tunnel_uninit,
971 	.ndo_start_xmit		= ip6gre_tunnel_xmit,
972 	.ndo_do_ioctl		= ip6gre_tunnel_ioctl,
973 	.ndo_change_mtu		= ip6_tnl_change_mtu,
974 	.ndo_get_stats64	= ip_tunnel_get_stats64,
975 	.ndo_get_iflink		= ip6_tnl_get_iflink,
976 };
977 
978 static void ip6gre_dev_free(struct net_device *dev)
979 {
980 	struct ip6_tnl *t = netdev_priv(dev);
981 
982 	dst_cache_destroy(&t->dst_cache);
983 	free_percpu(dev->tstats);
984 	free_netdev(dev);
985 }
986 
987 static void ip6gre_tunnel_setup(struct net_device *dev)
988 {
989 	dev->netdev_ops = &ip6gre_netdev_ops;
990 	dev->destructor = ip6gre_dev_free;
991 
992 	dev->type = ARPHRD_IP6GRE;
993 
994 	dev->flags |= IFF_NOARP;
995 	dev->addr_len = sizeof(struct in6_addr);
996 	netif_keep_dst(dev);
997 }
998 
999 static int ip6gre_tunnel_init_common(struct net_device *dev)
1000 {
1001 	struct ip6_tnl *tunnel;
1002 	int ret;
1003 	int t_hlen;
1004 
1005 	tunnel = netdev_priv(dev);
1006 
1007 	tunnel->dev = dev;
1008 	tunnel->net = dev_net(dev);
1009 	strcpy(tunnel->parms.name, dev->name);
1010 
1011 	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1012 	if (!dev->tstats)
1013 		return -ENOMEM;
1014 
1015 	ret = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL);
1016 	if (ret) {
1017 		free_percpu(dev->tstats);
1018 		dev->tstats = NULL;
1019 		return ret;
1020 	}
1021 
1022 	tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags);
1023 	tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen;
1024 	t_hlen = tunnel->hlen + sizeof(struct ipv6hdr);
1025 
1026 	dev->hard_header_len = LL_MAX_HEADER + t_hlen;
1027 	dev->mtu = ETH_DATA_LEN - t_hlen;
1028 	if (dev->type == ARPHRD_ETHER)
1029 		dev->mtu -= ETH_HLEN;
1030 	if (!(tunnel->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1031 		dev->mtu -= 8;
1032 
1033 	return 0;
1034 }
1035 
1036 static int ip6gre_tunnel_init(struct net_device *dev)
1037 {
1038 	struct ip6_tnl *tunnel;
1039 	int ret;
1040 
1041 	ret = ip6gre_tunnel_init_common(dev);
1042 	if (ret)
1043 		return ret;
1044 
1045 	tunnel = netdev_priv(dev);
1046 
1047 	memcpy(dev->dev_addr, &tunnel->parms.laddr, sizeof(struct in6_addr));
1048 	memcpy(dev->broadcast, &tunnel->parms.raddr, sizeof(struct in6_addr));
1049 
1050 	if (ipv6_addr_any(&tunnel->parms.raddr))
1051 		dev->header_ops = &ip6gre_header_ops;
1052 
1053 	return 0;
1054 }
1055 
1056 static void ip6gre_fb_tunnel_init(struct net_device *dev)
1057 {
1058 	struct ip6_tnl *tunnel = netdev_priv(dev);
1059 
1060 	tunnel->dev = dev;
1061 	tunnel->net = dev_net(dev);
1062 	strcpy(tunnel->parms.name, dev->name);
1063 
1064 	tunnel->hlen		= sizeof(struct ipv6hdr) + 4;
1065 
1066 	dev_hold(dev);
1067 }
1068 
1069 
1070 static struct inet6_protocol ip6gre_protocol __read_mostly = {
1071 	.handler     = gre_rcv,
1072 	.err_handler = ip6gre_err,
1073 	.flags       = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1074 };
1075 
1076 static void ip6gre_destroy_tunnels(struct net *net, struct list_head *head)
1077 {
1078 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1079 	struct net_device *dev, *aux;
1080 	int prio;
1081 
1082 	for_each_netdev_safe(net, dev, aux)
1083 		if (dev->rtnl_link_ops == &ip6gre_link_ops ||
1084 		    dev->rtnl_link_ops == &ip6gre_tap_ops)
1085 			unregister_netdevice_queue(dev, head);
1086 
1087 	for (prio = 0; prio < 4; prio++) {
1088 		int h;
1089 		for (h = 0; h < IP6_GRE_HASH_SIZE; h++) {
1090 			struct ip6_tnl *t;
1091 
1092 			t = rtnl_dereference(ign->tunnels[prio][h]);
1093 
1094 			while (t) {
1095 				/* If dev is in the same netns, it has already
1096 				 * been added to the list by the previous loop.
1097 				 */
1098 				if (!net_eq(dev_net(t->dev), net))
1099 					unregister_netdevice_queue(t->dev,
1100 								   head);
1101 				t = rtnl_dereference(t->next);
1102 			}
1103 		}
1104 	}
1105 }
1106 
1107 static int __net_init ip6gre_init_net(struct net *net)
1108 {
1109 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1110 	int err;
1111 
1112 	ign->fb_tunnel_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6gre0",
1113 					  NET_NAME_UNKNOWN,
1114 					  ip6gre_tunnel_setup);
1115 	if (!ign->fb_tunnel_dev) {
1116 		err = -ENOMEM;
1117 		goto err_alloc_dev;
1118 	}
1119 	dev_net_set(ign->fb_tunnel_dev, net);
1120 	/* FB netdevice is special: we have one, and only one per netns.
1121 	 * Allowing to move it to another netns is clearly unsafe.
1122 	 */
1123 	ign->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
1124 
1125 
1126 	ip6gre_fb_tunnel_init(ign->fb_tunnel_dev);
1127 	ign->fb_tunnel_dev->rtnl_link_ops = &ip6gre_link_ops;
1128 
1129 	err = register_netdev(ign->fb_tunnel_dev);
1130 	if (err)
1131 		goto err_reg_dev;
1132 
1133 	rcu_assign_pointer(ign->tunnels_wc[0],
1134 			   netdev_priv(ign->fb_tunnel_dev));
1135 	return 0;
1136 
1137 err_reg_dev:
1138 	ip6gre_dev_free(ign->fb_tunnel_dev);
1139 err_alloc_dev:
1140 	return err;
1141 }
1142 
1143 static void __net_exit ip6gre_exit_net(struct net *net)
1144 {
1145 	LIST_HEAD(list);
1146 
1147 	rtnl_lock();
1148 	ip6gre_destroy_tunnels(net, &list);
1149 	unregister_netdevice_many(&list);
1150 	rtnl_unlock();
1151 }
1152 
1153 static struct pernet_operations ip6gre_net_ops = {
1154 	.init = ip6gre_init_net,
1155 	.exit = ip6gre_exit_net,
1156 	.id   = &ip6gre_net_id,
1157 	.size = sizeof(struct ip6gre_net),
1158 };
1159 
1160 static int ip6gre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[])
1161 {
1162 	__be16 flags;
1163 
1164 	if (!data)
1165 		return 0;
1166 
1167 	flags = 0;
1168 	if (data[IFLA_GRE_IFLAGS])
1169 		flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1170 	if (data[IFLA_GRE_OFLAGS])
1171 		flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1172 	if (flags & (GRE_VERSION|GRE_ROUTING))
1173 		return -EINVAL;
1174 
1175 	return 0;
1176 }
1177 
1178 static int ip6gre_tap_validate(struct nlattr *tb[], struct nlattr *data[])
1179 {
1180 	struct in6_addr daddr;
1181 
1182 	if (tb[IFLA_ADDRESS]) {
1183 		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1184 			return -EINVAL;
1185 		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1186 			return -EADDRNOTAVAIL;
1187 	}
1188 
1189 	if (!data)
1190 		goto out;
1191 
1192 	if (data[IFLA_GRE_REMOTE]) {
1193 		daddr = nla_get_in6_addr(data[IFLA_GRE_REMOTE]);
1194 		if (ipv6_addr_any(&daddr))
1195 			return -EINVAL;
1196 	}
1197 
1198 out:
1199 	return ip6gre_tunnel_validate(tb, data);
1200 }
1201 
1202 
1203 static void ip6gre_netlink_parms(struct nlattr *data[],
1204 				struct __ip6_tnl_parm *parms)
1205 {
1206 	memset(parms, 0, sizeof(*parms));
1207 
1208 	if (!data)
1209 		return;
1210 
1211 	if (data[IFLA_GRE_LINK])
1212 		parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
1213 
1214 	if (data[IFLA_GRE_IFLAGS])
1215 		parms->i_flags = gre_flags_to_tnl_flags(
1216 				nla_get_be16(data[IFLA_GRE_IFLAGS]));
1217 
1218 	if (data[IFLA_GRE_OFLAGS])
1219 		parms->o_flags = gre_flags_to_tnl_flags(
1220 				nla_get_be16(data[IFLA_GRE_OFLAGS]));
1221 
1222 	if (data[IFLA_GRE_IKEY])
1223 		parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
1224 
1225 	if (data[IFLA_GRE_OKEY])
1226 		parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
1227 
1228 	if (data[IFLA_GRE_LOCAL])
1229 		parms->laddr = nla_get_in6_addr(data[IFLA_GRE_LOCAL]);
1230 
1231 	if (data[IFLA_GRE_REMOTE])
1232 		parms->raddr = nla_get_in6_addr(data[IFLA_GRE_REMOTE]);
1233 
1234 	if (data[IFLA_GRE_TTL])
1235 		parms->hop_limit = nla_get_u8(data[IFLA_GRE_TTL]);
1236 
1237 	if (data[IFLA_GRE_ENCAP_LIMIT])
1238 		parms->encap_limit = nla_get_u8(data[IFLA_GRE_ENCAP_LIMIT]);
1239 
1240 	if (data[IFLA_GRE_FLOWINFO])
1241 		parms->flowinfo = nla_get_be32(data[IFLA_GRE_FLOWINFO]);
1242 
1243 	if (data[IFLA_GRE_FLAGS])
1244 		parms->flags = nla_get_u32(data[IFLA_GRE_FLAGS]);
1245 }
1246 
1247 static int ip6gre_tap_init(struct net_device *dev)
1248 {
1249 	struct ip6_tnl *tunnel;
1250 	int ret;
1251 
1252 	ret = ip6gre_tunnel_init_common(dev);
1253 	if (ret)
1254 		return ret;
1255 
1256 	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1257 
1258 	tunnel = netdev_priv(dev);
1259 
1260 	ip6gre_tnl_link_config(tunnel, 1);
1261 
1262 	return 0;
1263 }
1264 
1265 static const struct net_device_ops ip6gre_tap_netdev_ops = {
1266 	.ndo_init = ip6gre_tap_init,
1267 	.ndo_uninit = ip6gre_tunnel_uninit,
1268 	.ndo_start_xmit = ip6gre_tunnel_xmit,
1269 	.ndo_set_mac_address = eth_mac_addr,
1270 	.ndo_validate_addr = eth_validate_addr,
1271 	.ndo_change_mtu = ip6_tnl_change_mtu,
1272 	.ndo_get_stats64 = ip_tunnel_get_stats64,
1273 	.ndo_get_iflink = ip6_tnl_get_iflink,
1274 };
1275 
1276 #define GRE6_FEATURES (NETIF_F_SG |		\
1277 		       NETIF_F_FRAGLIST |	\
1278 		       NETIF_F_HIGHDMA |		\
1279 		       NETIF_F_HW_CSUM)
1280 
1281 static void ip6gre_tap_setup(struct net_device *dev)
1282 {
1283 
1284 	ether_setup(dev);
1285 
1286 	dev->netdev_ops = &ip6gre_tap_netdev_ops;
1287 	dev->destructor = ip6gre_dev_free;
1288 
1289 	dev->features |= NETIF_F_NETNS_LOCAL;
1290 	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1291 	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1292 }
1293 
1294 static bool ip6gre_netlink_encap_parms(struct nlattr *data[],
1295 				       struct ip_tunnel_encap *ipencap)
1296 {
1297 	bool ret = false;
1298 
1299 	memset(ipencap, 0, sizeof(*ipencap));
1300 
1301 	if (!data)
1302 		return ret;
1303 
1304 	if (data[IFLA_GRE_ENCAP_TYPE]) {
1305 		ret = true;
1306 		ipencap->type = nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]);
1307 	}
1308 
1309 	if (data[IFLA_GRE_ENCAP_FLAGS]) {
1310 		ret = true;
1311 		ipencap->flags = nla_get_u16(data[IFLA_GRE_ENCAP_FLAGS]);
1312 	}
1313 
1314 	if (data[IFLA_GRE_ENCAP_SPORT]) {
1315 		ret = true;
1316 		ipencap->sport = nla_get_be16(data[IFLA_GRE_ENCAP_SPORT]);
1317 	}
1318 
1319 	if (data[IFLA_GRE_ENCAP_DPORT]) {
1320 		ret = true;
1321 		ipencap->dport = nla_get_be16(data[IFLA_GRE_ENCAP_DPORT]);
1322 	}
1323 
1324 	return ret;
1325 }
1326 
1327 static int ip6gre_newlink(struct net *src_net, struct net_device *dev,
1328 	struct nlattr *tb[], struct nlattr *data[])
1329 {
1330 	struct ip6_tnl *nt;
1331 	struct net *net = dev_net(dev);
1332 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1333 	struct ip_tunnel_encap ipencap;
1334 	int err;
1335 
1336 	nt = netdev_priv(dev);
1337 
1338 	if (ip6gre_netlink_encap_parms(data, &ipencap)) {
1339 		int err = ip6_tnl_encap_setup(nt, &ipencap);
1340 
1341 		if (err < 0)
1342 			return err;
1343 	}
1344 
1345 	ip6gre_netlink_parms(data, &nt->parms);
1346 
1347 	if (ip6gre_tunnel_find(net, &nt->parms, dev->type))
1348 		return -EEXIST;
1349 
1350 	if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
1351 		eth_hw_addr_random(dev);
1352 
1353 	nt->dev = dev;
1354 	nt->net = dev_net(dev);
1355 	ip6gre_tnl_link_config(nt, !tb[IFLA_MTU]);
1356 
1357 	dev->features		|= GRE6_FEATURES;
1358 	dev->hw_features	|= GRE6_FEATURES;
1359 
1360 	if (!(nt->parms.o_flags & TUNNEL_SEQ)) {
1361 		/* TCP offload with GRE SEQ is not supported, nor
1362 		 * can we support 2 levels of outer headers requiring
1363 		 * an update.
1364 		 */
1365 		if (!(nt->parms.o_flags & TUNNEL_CSUM) ||
1366 		    (nt->encap.type == TUNNEL_ENCAP_NONE)) {
1367 			dev->features    |= NETIF_F_GSO_SOFTWARE;
1368 			dev->hw_features |= NETIF_F_GSO_SOFTWARE;
1369 		}
1370 
1371 		/* Can use a lockless transmit, unless we generate
1372 		 * output sequences
1373 		 */
1374 		dev->features |= NETIF_F_LLTX;
1375 	}
1376 
1377 	err = register_netdevice(dev);
1378 	if (err)
1379 		goto out;
1380 
1381 	dev_hold(dev);
1382 	ip6gre_tunnel_link(ign, nt);
1383 
1384 out:
1385 	return err;
1386 }
1387 
1388 static int ip6gre_changelink(struct net_device *dev, struct nlattr *tb[],
1389 			    struct nlattr *data[])
1390 {
1391 	struct ip6_tnl *t, *nt = netdev_priv(dev);
1392 	struct net *net = nt->net;
1393 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1394 	struct __ip6_tnl_parm p;
1395 	struct ip_tunnel_encap ipencap;
1396 
1397 	if (dev == ign->fb_tunnel_dev)
1398 		return -EINVAL;
1399 
1400 	if (ip6gre_netlink_encap_parms(data, &ipencap)) {
1401 		int err = ip6_tnl_encap_setup(nt, &ipencap);
1402 
1403 		if (err < 0)
1404 			return err;
1405 	}
1406 
1407 	ip6gre_netlink_parms(data, &p);
1408 
1409 	t = ip6gre_tunnel_locate(net, &p, 0);
1410 
1411 	if (t) {
1412 		if (t->dev != dev)
1413 			return -EEXIST;
1414 	} else {
1415 		t = nt;
1416 	}
1417 
1418 	ip6gre_tunnel_unlink(ign, t);
1419 	ip6gre_tnl_change(t, &p, !tb[IFLA_MTU]);
1420 	ip6gre_tunnel_link(ign, t);
1421 	return 0;
1422 }
1423 
1424 static void ip6gre_dellink(struct net_device *dev, struct list_head *head)
1425 {
1426 	struct net *net = dev_net(dev);
1427 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1428 
1429 	if (dev != ign->fb_tunnel_dev)
1430 		unregister_netdevice_queue(dev, head);
1431 }
1432 
1433 static size_t ip6gre_get_size(const struct net_device *dev)
1434 {
1435 	return
1436 		/* IFLA_GRE_LINK */
1437 		nla_total_size(4) +
1438 		/* IFLA_GRE_IFLAGS */
1439 		nla_total_size(2) +
1440 		/* IFLA_GRE_OFLAGS */
1441 		nla_total_size(2) +
1442 		/* IFLA_GRE_IKEY */
1443 		nla_total_size(4) +
1444 		/* IFLA_GRE_OKEY */
1445 		nla_total_size(4) +
1446 		/* IFLA_GRE_LOCAL */
1447 		nla_total_size(sizeof(struct in6_addr)) +
1448 		/* IFLA_GRE_REMOTE */
1449 		nla_total_size(sizeof(struct in6_addr)) +
1450 		/* IFLA_GRE_TTL */
1451 		nla_total_size(1) +
1452 		/* IFLA_GRE_ENCAP_LIMIT */
1453 		nla_total_size(1) +
1454 		/* IFLA_GRE_FLOWINFO */
1455 		nla_total_size(4) +
1456 		/* IFLA_GRE_FLAGS */
1457 		nla_total_size(4) +
1458 		/* IFLA_GRE_ENCAP_TYPE */
1459 		nla_total_size(2) +
1460 		/* IFLA_GRE_ENCAP_FLAGS */
1461 		nla_total_size(2) +
1462 		/* IFLA_GRE_ENCAP_SPORT */
1463 		nla_total_size(2) +
1464 		/* IFLA_GRE_ENCAP_DPORT */
1465 		nla_total_size(2) +
1466 		0;
1467 }
1468 
1469 static int ip6gre_fill_info(struct sk_buff *skb, const struct net_device *dev)
1470 {
1471 	struct ip6_tnl *t = netdev_priv(dev);
1472 	struct __ip6_tnl_parm *p = &t->parms;
1473 
1474 	if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
1475 	    nla_put_be16(skb, IFLA_GRE_IFLAGS,
1476 			 gre_tnl_flags_to_gre_flags(p->i_flags)) ||
1477 	    nla_put_be16(skb, IFLA_GRE_OFLAGS,
1478 			 gre_tnl_flags_to_gre_flags(p->o_flags)) ||
1479 	    nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
1480 	    nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
1481 	    nla_put_in6_addr(skb, IFLA_GRE_LOCAL, &p->laddr) ||
1482 	    nla_put_in6_addr(skb, IFLA_GRE_REMOTE, &p->raddr) ||
1483 	    nla_put_u8(skb, IFLA_GRE_TTL, p->hop_limit) ||
1484 	    nla_put_u8(skb, IFLA_GRE_ENCAP_LIMIT, p->encap_limit) ||
1485 	    nla_put_be32(skb, IFLA_GRE_FLOWINFO, p->flowinfo) ||
1486 	    nla_put_u32(skb, IFLA_GRE_FLAGS, p->flags))
1487 		goto nla_put_failure;
1488 
1489 	if (nla_put_u16(skb, IFLA_GRE_ENCAP_TYPE,
1490 			t->encap.type) ||
1491 	    nla_put_be16(skb, IFLA_GRE_ENCAP_SPORT,
1492 			 t->encap.sport) ||
1493 	    nla_put_be16(skb, IFLA_GRE_ENCAP_DPORT,
1494 			 t->encap.dport) ||
1495 	    nla_put_u16(skb, IFLA_GRE_ENCAP_FLAGS,
1496 			t->encap.flags))
1497 		goto nla_put_failure;
1498 
1499 	return 0;
1500 
1501 nla_put_failure:
1502 	return -EMSGSIZE;
1503 }
1504 
1505 static const struct nla_policy ip6gre_policy[IFLA_GRE_MAX + 1] = {
1506 	[IFLA_GRE_LINK]        = { .type = NLA_U32 },
1507 	[IFLA_GRE_IFLAGS]      = { .type = NLA_U16 },
1508 	[IFLA_GRE_OFLAGS]      = { .type = NLA_U16 },
1509 	[IFLA_GRE_IKEY]        = { .type = NLA_U32 },
1510 	[IFLA_GRE_OKEY]        = { .type = NLA_U32 },
1511 	[IFLA_GRE_LOCAL]       = { .len = FIELD_SIZEOF(struct ipv6hdr, saddr) },
1512 	[IFLA_GRE_REMOTE]      = { .len = FIELD_SIZEOF(struct ipv6hdr, daddr) },
1513 	[IFLA_GRE_TTL]         = { .type = NLA_U8 },
1514 	[IFLA_GRE_ENCAP_LIMIT] = { .type = NLA_U8 },
1515 	[IFLA_GRE_FLOWINFO]    = { .type = NLA_U32 },
1516 	[IFLA_GRE_FLAGS]       = { .type = NLA_U32 },
1517 	[IFLA_GRE_ENCAP_TYPE]   = { .type = NLA_U16 },
1518 	[IFLA_GRE_ENCAP_FLAGS]  = { .type = NLA_U16 },
1519 	[IFLA_GRE_ENCAP_SPORT]  = { .type = NLA_U16 },
1520 	[IFLA_GRE_ENCAP_DPORT]  = { .type = NLA_U16 },
1521 };
1522 
1523 static struct rtnl_link_ops ip6gre_link_ops __read_mostly = {
1524 	.kind		= "ip6gre",
1525 	.maxtype	= IFLA_GRE_MAX,
1526 	.policy		= ip6gre_policy,
1527 	.priv_size	= sizeof(struct ip6_tnl),
1528 	.setup		= ip6gre_tunnel_setup,
1529 	.validate	= ip6gre_tunnel_validate,
1530 	.newlink	= ip6gre_newlink,
1531 	.changelink	= ip6gre_changelink,
1532 	.dellink	= ip6gre_dellink,
1533 	.get_size	= ip6gre_get_size,
1534 	.fill_info	= ip6gre_fill_info,
1535 	.get_link_net	= ip6_tnl_get_link_net,
1536 };
1537 
1538 static struct rtnl_link_ops ip6gre_tap_ops __read_mostly = {
1539 	.kind		= "ip6gretap",
1540 	.maxtype	= IFLA_GRE_MAX,
1541 	.policy		= ip6gre_policy,
1542 	.priv_size	= sizeof(struct ip6_tnl),
1543 	.setup		= ip6gre_tap_setup,
1544 	.validate	= ip6gre_tap_validate,
1545 	.newlink	= ip6gre_newlink,
1546 	.changelink	= ip6gre_changelink,
1547 	.get_size	= ip6gre_get_size,
1548 	.fill_info	= ip6gre_fill_info,
1549 	.get_link_net	= ip6_tnl_get_link_net,
1550 };
1551 
1552 /*
1553  *	And now the modules code and kernel interface.
1554  */
1555 
1556 static int __init ip6gre_init(void)
1557 {
1558 	int err;
1559 
1560 	pr_info("GRE over IPv6 tunneling driver\n");
1561 
1562 	err = register_pernet_device(&ip6gre_net_ops);
1563 	if (err < 0)
1564 		return err;
1565 
1566 	err = inet6_add_protocol(&ip6gre_protocol, IPPROTO_GRE);
1567 	if (err < 0) {
1568 		pr_info("%s: can't add protocol\n", __func__);
1569 		goto add_proto_failed;
1570 	}
1571 
1572 	err = rtnl_link_register(&ip6gre_link_ops);
1573 	if (err < 0)
1574 		goto rtnl_link_failed;
1575 
1576 	err = rtnl_link_register(&ip6gre_tap_ops);
1577 	if (err < 0)
1578 		goto tap_ops_failed;
1579 
1580 out:
1581 	return err;
1582 
1583 tap_ops_failed:
1584 	rtnl_link_unregister(&ip6gre_link_ops);
1585 rtnl_link_failed:
1586 	inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
1587 add_proto_failed:
1588 	unregister_pernet_device(&ip6gre_net_ops);
1589 	goto out;
1590 }
1591 
1592 static void __exit ip6gre_fini(void)
1593 {
1594 	rtnl_link_unregister(&ip6gre_tap_ops);
1595 	rtnl_link_unregister(&ip6gre_link_ops);
1596 	inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
1597 	unregister_pernet_device(&ip6gre_net_ops);
1598 }
1599 
1600 module_init(ip6gre_init);
1601 module_exit(ip6gre_fini);
1602 MODULE_LICENSE("GPL");
1603 MODULE_AUTHOR("D. Kozlov (xeb@mail.ru)");
1604 MODULE_DESCRIPTION("GRE over IPv6 tunneling device");
1605 MODULE_ALIAS_RTNL_LINK("ip6gre");
1606 MODULE_ALIAS_RTNL_LINK("ip6gretap");
1607 MODULE_ALIAS_NETDEV("ip6gre0");
1608