xref: /linux/net/ipv6/ip6_tunnel.c (revision 9410645520e9b820069761f3450ef6661418e279)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *	IPv6 tunneling device
4  *	Linux INET6 implementation
5  *
6  *	Authors:
7  *	Ville Nuorvala		<vnuorval@tcs.hut.fi>
8  *	Yasuyuki Kozakai	<kozakai@linux-ipv6.org>
9  *
10  *      Based on:
11  *      linux/net/ipv6/sit.c and linux/net/ipv4/ipip.c
12  *
13  *      RFC 2473
14  */
15 
16 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
17 
18 #include <linux/module.h>
19 #include <linux/capability.h>
20 #include <linux/errno.h>
21 #include <linux/types.h>
22 #include <linux/sockios.h>
23 #include <linux/icmp.h>
24 #include <linux/if.h>
25 #include <linux/in.h>
26 #include <linux/ip.h>
27 #include <linux/net.h>
28 #include <linux/in6.h>
29 #include <linux/netdevice.h>
30 #include <linux/if_arp.h>
31 #include <linux/icmpv6.h>
32 #include <linux/init.h>
33 #include <linux/route.h>
34 #include <linux/rtnetlink.h>
35 #include <linux/netfilter_ipv6.h>
36 #include <linux/slab.h>
37 #include <linux/hash.h>
38 #include <linux/etherdevice.h>
39 
40 #include <linux/uaccess.h>
41 #include <linux/atomic.h>
42 
43 #include <net/icmp.h>
44 #include <net/ip.h>
45 #include <net/ip_tunnels.h>
46 #include <net/ipv6.h>
47 #include <net/ip6_route.h>
48 #include <net/addrconf.h>
49 #include <net/ip6_tunnel.h>
50 #include <net/xfrm.h>
51 #include <net/dsfield.h>
52 #include <net/inet_ecn.h>
53 #include <net/net_namespace.h>
54 #include <net/netns/generic.h>
55 #include <net/dst_metadata.h>
56 #include <net/inet_dscp.h>
57 
58 MODULE_AUTHOR("Ville Nuorvala");
59 MODULE_DESCRIPTION("IPv6 tunneling device");
60 MODULE_LICENSE("GPL");
61 MODULE_ALIAS_RTNL_LINK("ip6tnl");
62 MODULE_ALIAS_NETDEV("ip6tnl0");
63 
64 #define IP6_TUNNEL_HASH_SIZE_SHIFT  5
65 #define IP6_TUNNEL_HASH_SIZE (1 << IP6_TUNNEL_HASH_SIZE_SHIFT)
66 
67 static bool log_ecn_error = true;
68 module_param(log_ecn_error, bool, 0644);
69 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
70 
HASH(const struct in6_addr * addr1,const struct in6_addr * addr2)71 static u32 HASH(const struct in6_addr *addr1, const struct in6_addr *addr2)
72 {
73 	u32 hash = ipv6_addr_hash(addr1) ^ ipv6_addr_hash(addr2);
74 
75 	return hash_32(hash, IP6_TUNNEL_HASH_SIZE_SHIFT);
76 }
77 
78 static int ip6_tnl_dev_init(struct net_device *dev);
79 static void ip6_tnl_dev_setup(struct net_device *dev);
80 static struct rtnl_link_ops ip6_link_ops __read_mostly;
81 
82 static unsigned int ip6_tnl_net_id __read_mostly;
83 struct ip6_tnl_net {
84 	/* the IPv6 tunnel fallback device */
85 	struct net_device *fb_tnl_dev;
86 	/* lists for storing tunnels in use */
87 	struct ip6_tnl __rcu *tnls_r_l[IP6_TUNNEL_HASH_SIZE];
88 	struct ip6_tnl __rcu *tnls_wc[1];
89 	struct ip6_tnl __rcu **tnls[2];
90 	struct ip6_tnl __rcu *collect_md_tun;
91 };
92 
ip6_tnl_mpls_supported(void)93 static inline int ip6_tnl_mpls_supported(void)
94 {
95 	return IS_ENABLED(CONFIG_MPLS);
96 }
97 
98 #define for_each_ip6_tunnel_rcu(start) \
99 	for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
100 
101 /**
102  * ip6_tnl_lookup - fetch tunnel matching the end-point addresses
103  *   @net: network namespace
104  *   @link: ifindex of underlying interface
105  *   @remote: the address of the tunnel exit-point
106  *   @local: the address of the tunnel entry-point
107  *
108  * Return:
109  *   tunnel matching given end-points if found,
110  *   else fallback tunnel if its device is up,
111  *   else %NULL
112  **/
113 
114 static struct ip6_tnl *
ip6_tnl_lookup(struct net * net,int link,const struct in6_addr * remote,const struct in6_addr * local)115 ip6_tnl_lookup(struct net *net, int link,
116 	       const struct in6_addr *remote, const struct in6_addr *local)
117 {
118 	unsigned int hash = HASH(remote, local);
119 	struct ip6_tnl *t, *cand = NULL;
120 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
121 	struct in6_addr any;
122 
123 	for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
124 		if (!ipv6_addr_equal(local, &t->parms.laddr) ||
125 		    !ipv6_addr_equal(remote, &t->parms.raddr) ||
126 		    !(t->dev->flags & IFF_UP))
127 			continue;
128 
129 		if (link == t->parms.link)
130 			return t;
131 		else
132 			cand = t;
133 	}
134 
135 	memset(&any, 0, sizeof(any));
136 	hash = HASH(&any, local);
137 	for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
138 		if (!ipv6_addr_equal(local, &t->parms.laddr) ||
139 		    !ipv6_addr_any(&t->parms.raddr) ||
140 		    !(t->dev->flags & IFF_UP))
141 			continue;
142 
143 		if (link == t->parms.link)
144 			return t;
145 		else if (!cand)
146 			cand = t;
147 	}
148 
149 	hash = HASH(remote, &any);
150 	for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
151 		if (!ipv6_addr_equal(remote, &t->parms.raddr) ||
152 		    !ipv6_addr_any(&t->parms.laddr) ||
153 		    !(t->dev->flags & IFF_UP))
154 			continue;
155 
156 		if (link == t->parms.link)
157 			return t;
158 		else if (!cand)
159 			cand = t;
160 	}
161 
162 	if (cand)
163 		return cand;
164 
165 	t = rcu_dereference(ip6n->collect_md_tun);
166 	if (t && t->dev->flags & IFF_UP)
167 		return t;
168 
169 	t = rcu_dereference(ip6n->tnls_wc[0]);
170 	if (t && (t->dev->flags & IFF_UP))
171 		return t;
172 
173 	return NULL;
174 }
175 
176 /**
177  * ip6_tnl_bucket - get head of list matching given tunnel parameters
178  *   @ip6n: the private data for ip6_vti in the netns
179  *   @p: parameters containing tunnel end-points
180  *
181  * Description:
182  *   ip6_tnl_bucket() returns the head of the list matching the
183  *   &struct in6_addr entries laddr and raddr in @p.
184  *
185  * Return: head of IPv6 tunnel list
186  **/
187 
188 static struct ip6_tnl __rcu **
ip6_tnl_bucket(struct ip6_tnl_net * ip6n,const struct __ip6_tnl_parm * p)189 ip6_tnl_bucket(struct ip6_tnl_net *ip6n, const struct __ip6_tnl_parm *p)
190 {
191 	const struct in6_addr *remote = &p->raddr;
192 	const struct in6_addr *local = &p->laddr;
193 	unsigned int h = 0;
194 	int prio = 0;
195 
196 	if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) {
197 		prio = 1;
198 		h = HASH(remote, local);
199 	}
200 	return &ip6n->tnls[prio][h];
201 }
202 
203 /**
204  * ip6_tnl_link - add tunnel to hash table
205  *   @ip6n: the private data for ip6_vti in the netns
206  *   @t: tunnel to be added
207  **/
208 
209 static void
ip6_tnl_link(struct ip6_tnl_net * ip6n,struct ip6_tnl * t)210 ip6_tnl_link(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
211 {
212 	struct ip6_tnl __rcu **tp = ip6_tnl_bucket(ip6n, &t->parms);
213 
214 	if (t->parms.collect_md)
215 		rcu_assign_pointer(ip6n->collect_md_tun, t);
216 	rcu_assign_pointer(t->next , rtnl_dereference(*tp));
217 	rcu_assign_pointer(*tp, t);
218 }
219 
220 /**
221  * ip6_tnl_unlink - remove tunnel from hash table
222  *   @ip6n: the private data for ip6_vti in the netns
223  *   @t: tunnel to be removed
224  **/
225 
226 static void
ip6_tnl_unlink(struct ip6_tnl_net * ip6n,struct ip6_tnl * t)227 ip6_tnl_unlink(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
228 {
229 	struct ip6_tnl __rcu **tp;
230 	struct ip6_tnl *iter;
231 
232 	if (t->parms.collect_md)
233 		rcu_assign_pointer(ip6n->collect_md_tun, NULL);
234 
235 	for (tp = ip6_tnl_bucket(ip6n, &t->parms);
236 	     (iter = rtnl_dereference(*tp)) != NULL;
237 	     tp = &iter->next) {
238 		if (t == iter) {
239 			rcu_assign_pointer(*tp, t->next);
240 			break;
241 		}
242 	}
243 }
244 
ip6_dev_free(struct net_device * dev)245 static void ip6_dev_free(struct net_device *dev)
246 {
247 	struct ip6_tnl *t = netdev_priv(dev);
248 
249 	gro_cells_destroy(&t->gro_cells);
250 	dst_cache_destroy(&t->dst_cache);
251 }
252 
ip6_tnl_create2(struct net_device * dev)253 static int ip6_tnl_create2(struct net_device *dev)
254 {
255 	struct ip6_tnl *t = netdev_priv(dev);
256 	struct net *net = dev_net(dev);
257 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
258 	int err;
259 
260 	dev->rtnl_link_ops = &ip6_link_ops;
261 	err = register_netdevice(dev);
262 	if (err < 0)
263 		goto out;
264 
265 	strcpy(t->parms.name, dev->name);
266 
267 	ip6_tnl_link(ip6n, t);
268 	return 0;
269 
270 out:
271 	return err;
272 }
273 
274 /**
275  * ip6_tnl_create - create a new tunnel
276  *   @net: network namespace
277  *   @p: tunnel parameters
278  *
279  * Description:
280  *   Create tunnel matching given parameters.
281  *
282  * Return:
283  *   created tunnel or error pointer
284  **/
285 
ip6_tnl_create(struct net * net,struct __ip6_tnl_parm * p)286 static struct ip6_tnl *ip6_tnl_create(struct net *net, struct __ip6_tnl_parm *p)
287 {
288 	struct net_device *dev;
289 	struct ip6_tnl *t;
290 	char name[IFNAMSIZ];
291 	int err = -E2BIG;
292 
293 	if (p->name[0]) {
294 		if (!dev_valid_name(p->name))
295 			goto failed;
296 		strscpy(name, p->name, IFNAMSIZ);
297 	} else {
298 		sprintf(name, "ip6tnl%%d");
299 	}
300 	err = -ENOMEM;
301 	dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
302 			   ip6_tnl_dev_setup);
303 	if (!dev)
304 		goto failed;
305 
306 	dev_net_set(dev, net);
307 
308 	t = netdev_priv(dev);
309 	t->parms = *p;
310 	t->net = dev_net(dev);
311 	err = ip6_tnl_create2(dev);
312 	if (err < 0)
313 		goto failed_free;
314 
315 	return t;
316 
317 failed_free:
318 	free_netdev(dev);
319 failed:
320 	return ERR_PTR(err);
321 }
322 
323 /**
324  * ip6_tnl_locate - find or create tunnel matching given parameters
325  *   @net: network namespace
326  *   @p: tunnel parameters
327  *   @create: != 0 if allowed to create new tunnel if no match found
328  *
329  * Description:
330  *   ip6_tnl_locate() first tries to locate an existing tunnel
331  *   based on @parms. If this is unsuccessful, but @create is set a new
332  *   tunnel device is created and registered for use.
333  *
334  * Return:
335  *   matching tunnel or error pointer
336  **/
337 
ip6_tnl_locate(struct net * net,struct __ip6_tnl_parm * p,int create)338 static struct ip6_tnl *ip6_tnl_locate(struct net *net,
339 		struct __ip6_tnl_parm *p, int create)
340 {
341 	const struct in6_addr *remote = &p->raddr;
342 	const struct in6_addr *local = &p->laddr;
343 	struct ip6_tnl __rcu **tp;
344 	struct ip6_tnl *t;
345 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
346 
347 	for (tp = ip6_tnl_bucket(ip6n, p);
348 	     (t = rtnl_dereference(*tp)) != NULL;
349 	     tp = &t->next) {
350 		if (ipv6_addr_equal(local, &t->parms.laddr) &&
351 		    ipv6_addr_equal(remote, &t->parms.raddr) &&
352 		    p->link == t->parms.link) {
353 			if (create)
354 				return ERR_PTR(-EEXIST);
355 
356 			return t;
357 		}
358 	}
359 	if (!create)
360 		return ERR_PTR(-ENODEV);
361 	return ip6_tnl_create(net, p);
362 }
363 
364 /**
365  * ip6_tnl_dev_uninit - tunnel device uninitializer
366  *   @dev: the device to be destroyed
367  *
368  * Description:
369  *   ip6_tnl_dev_uninit() removes tunnel from its list
370  **/
371 
372 static void
ip6_tnl_dev_uninit(struct net_device * dev)373 ip6_tnl_dev_uninit(struct net_device *dev)
374 {
375 	struct ip6_tnl *t = netdev_priv(dev);
376 	struct net *net = t->net;
377 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
378 
379 	if (dev == ip6n->fb_tnl_dev)
380 		RCU_INIT_POINTER(ip6n->tnls_wc[0], NULL);
381 	else
382 		ip6_tnl_unlink(ip6n, t);
383 	dst_cache_reset(&t->dst_cache);
384 	netdev_put(dev, &t->dev_tracker);
385 }
386 
387 /**
388  * ip6_tnl_parse_tlv_enc_lim - handle encapsulation limit option
389  *   @skb: received socket buffer
390  *   @raw: the ICMPv6 error message data
391  *
392  * Return:
393  *   0 if none was found,
394  *   else index to encapsulation limit
395  **/
396 
ip6_tnl_parse_tlv_enc_lim(struct sk_buff * skb,__u8 * raw)397 __u16 ip6_tnl_parse_tlv_enc_lim(struct sk_buff *skb, __u8 *raw)
398 {
399 	const struct ipv6hdr *ipv6h = (const struct ipv6hdr *)raw;
400 	unsigned int nhoff = raw - skb->data;
401 	unsigned int off = nhoff + sizeof(*ipv6h);
402 	u8 nexthdr = ipv6h->nexthdr;
403 
404 	while (ipv6_ext_hdr(nexthdr) && nexthdr != NEXTHDR_NONE) {
405 		struct ipv6_opt_hdr *hdr;
406 		u16 optlen;
407 
408 		if (!pskb_may_pull(skb, off + sizeof(*hdr)))
409 			break;
410 
411 		hdr = (struct ipv6_opt_hdr *)(skb->data + off);
412 		if (nexthdr == NEXTHDR_FRAGMENT) {
413 			optlen = 8;
414 		} else if (nexthdr == NEXTHDR_AUTH) {
415 			optlen = ipv6_authlen(hdr);
416 		} else {
417 			optlen = ipv6_optlen(hdr);
418 		}
419 
420 		if (!pskb_may_pull(skb, off + optlen))
421 			break;
422 
423 		hdr = (struct ipv6_opt_hdr *)(skb->data + off);
424 		if (nexthdr == NEXTHDR_FRAGMENT) {
425 			struct frag_hdr *frag_hdr = (struct frag_hdr *)hdr;
426 
427 			if (frag_hdr->frag_off)
428 				break;
429 		}
430 		if (nexthdr == NEXTHDR_DEST) {
431 			u16 i = 2;
432 
433 			while (1) {
434 				struct ipv6_tlv_tnl_enc_lim *tel;
435 
436 				/* No more room for encapsulation limit */
437 				if (i + sizeof(*tel) > optlen)
438 					break;
439 
440 				tel = (struct ipv6_tlv_tnl_enc_lim *)(skb->data + off + i);
441 				/* return index of option if found and valid */
442 				if (tel->type == IPV6_TLV_TNL_ENCAP_LIMIT &&
443 				    tel->length == 1)
444 					return i + off - nhoff;
445 				/* else jump to next option */
446 				if (tel->type)
447 					i += tel->length + 2;
448 				else
449 					i++;
450 			}
451 		}
452 		nexthdr = hdr->nexthdr;
453 		off += optlen;
454 	}
455 	return 0;
456 }
457 EXPORT_SYMBOL(ip6_tnl_parse_tlv_enc_lim);
458 
459 /* ip6_tnl_err() should handle errors in the tunnel according to the
460  * specifications in RFC 2473.
461  */
462 static int
ip6_tnl_err(struct sk_buff * skb,__u8 ipproto,struct inet6_skb_parm * opt,u8 * type,u8 * code,int * msg,__u32 * info,int offset)463 ip6_tnl_err(struct sk_buff *skb, __u8 ipproto, struct inet6_skb_parm *opt,
464 	    u8 *type, u8 *code, int *msg, __u32 *info, int offset)
465 {
466 	const struct ipv6hdr *ipv6h = (const struct ipv6hdr *)skb->data;
467 	struct net *net = dev_net(skb->dev);
468 	u8 rel_type = ICMPV6_DEST_UNREACH;
469 	u8 rel_code = ICMPV6_ADDR_UNREACH;
470 	__u32 rel_info = 0;
471 	struct ip6_tnl *t;
472 	int err = -ENOENT;
473 	int rel_msg = 0;
474 	u8 tproto;
475 	__u16 len;
476 
477 	/* If the packet doesn't contain the original IPv6 header we are
478 	   in trouble since we might need the source address for further
479 	   processing of the error. */
480 
481 	rcu_read_lock();
482 	t = ip6_tnl_lookup(dev_net(skb->dev), skb->dev->ifindex, &ipv6h->daddr, &ipv6h->saddr);
483 	if (!t)
484 		goto out;
485 
486 	tproto = READ_ONCE(t->parms.proto);
487 	if (tproto != ipproto && tproto != 0)
488 		goto out;
489 
490 	err = 0;
491 
492 	switch (*type) {
493 	case ICMPV6_DEST_UNREACH:
494 		net_dbg_ratelimited("%s: Path to destination invalid or inactive!\n",
495 				    t->parms.name);
496 		rel_msg = 1;
497 		break;
498 	case ICMPV6_TIME_EXCEED:
499 		if ((*code) == ICMPV6_EXC_HOPLIMIT) {
500 			net_dbg_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
501 					    t->parms.name);
502 			rel_msg = 1;
503 		}
504 		break;
505 	case ICMPV6_PARAMPROB: {
506 		struct ipv6_tlv_tnl_enc_lim *tel;
507 		__u32 teli;
508 
509 		teli = 0;
510 		if ((*code) == ICMPV6_HDR_FIELD)
511 			teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
512 
513 		if (teli && teli == *info - 2) {
514 			tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
515 			if (tel->encap_limit == 0) {
516 				net_dbg_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
517 						    t->parms.name);
518 				rel_msg = 1;
519 			}
520 		} else {
521 			net_dbg_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
522 					    t->parms.name);
523 		}
524 		break;
525 	}
526 	case ICMPV6_PKT_TOOBIG: {
527 		__u32 mtu;
528 
529 		ip6_update_pmtu(skb, net, htonl(*info), 0, 0,
530 				sock_net_uid(net, NULL));
531 		mtu = *info - offset;
532 		if (mtu < IPV6_MIN_MTU)
533 			mtu = IPV6_MIN_MTU;
534 		len = sizeof(*ipv6h) + ntohs(ipv6h->payload_len);
535 		if (len > mtu) {
536 			rel_type = ICMPV6_PKT_TOOBIG;
537 			rel_code = 0;
538 			rel_info = mtu;
539 			rel_msg = 1;
540 		}
541 		break;
542 	}
543 	case NDISC_REDIRECT:
544 		ip6_redirect(skb, net, skb->dev->ifindex, 0,
545 			     sock_net_uid(net, NULL));
546 		break;
547 	}
548 
549 	*type = rel_type;
550 	*code = rel_code;
551 	*info = rel_info;
552 	*msg = rel_msg;
553 
554 out:
555 	rcu_read_unlock();
556 	return err;
557 }
558 
559 static int
ip4ip6_err(struct sk_buff * skb,struct inet6_skb_parm * opt,u8 type,u8 code,int offset,__be32 info)560 ip4ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
561 	   u8 type, u8 code, int offset, __be32 info)
562 {
563 	__u32 rel_info = ntohl(info);
564 	const struct iphdr *eiph;
565 	struct sk_buff *skb2;
566 	int err, rel_msg = 0;
567 	u8 rel_type = type;
568 	u8 rel_code = code;
569 	struct rtable *rt;
570 	struct flowi4 fl4;
571 
572 	err = ip6_tnl_err(skb, IPPROTO_IPIP, opt, &rel_type, &rel_code,
573 			  &rel_msg, &rel_info, offset);
574 	if (err < 0)
575 		return err;
576 
577 	if (rel_msg == 0)
578 		return 0;
579 
580 	switch (rel_type) {
581 	case ICMPV6_DEST_UNREACH:
582 		if (rel_code != ICMPV6_ADDR_UNREACH)
583 			return 0;
584 		rel_type = ICMP_DEST_UNREACH;
585 		rel_code = ICMP_HOST_UNREACH;
586 		break;
587 	case ICMPV6_PKT_TOOBIG:
588 		if (rel_code != 0)
589 			return 0;
590 		rel_type = ICMP_DEST_UNREACH;
591 		rel_code = ICMP_FRAG_NEEDED;
592 		break;
593 	default:
594 		return 0;
595 	}
596 
597 	if (!pskb_may_pull(skb, offset + sizeof(struct iphdr)))
598 		return 0;
599 
600 	skb2 = skb_clone(skb, GFP_ATOMIC);
601 	if (!skb2)
602 		return 0;
603 
604 	skb_dst_drop(skb2);
605 
606 	skb_pull(skb2, offset);
607 	skb_reset_network_header(skb2);
608 	eiph = ip_hdr(skb2);
609 
610 	/* Try to guess incoming interface */
611 	rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL, eiph->saddr,
612 				   0, 0, 0, IPPROTO_IPIP,
613 				   eiph->tos & INET_DSCP_MASK, 0);
614 	if (IS_ERR(rt))
615 		goto out;
616 
617 	skb2->dev = rt->dst.dev;
618 	ip_rt_put(rt);
619 
620 	/* route "incoming" packet */
621 	if (rt->rt_flags & RTCF_LOCAL) {
622 		rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL,
623 					   eiph->daddr, eiph->saddr, 0, 0,
624 					   IPPROTO_IPIP,
625 					   eiph->tos & INET_DSCP_MASK, 0);
626 		if (IS_ERR(rt) || rt->dst.dev->type != ARPHRD_TUNNEL6) {
627 			if (!IS_ERR(rt))
628 				ip_rt_put(rt);
629 			goto out;
630 		}
631 		skb_dst_set(skb2, &rt->dst);
632 	} else {
633 		if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos,
634 				   skb2->dev) ||
635 		    skb_dst(skb2)->dev->type != ARPHRD_TUNNEL6)
636 			goto out;
637 	}
638 
639 	/* change mtu on this route */
640 	if (rel_type == ICMP_DEST_UNREACH && rel_code == ICMP_FRAG_NEEDED) {
641 		if (rel_info > dst_mtu(skb_dst(skb2)))
642 			goto out;
643 
644 		skb_dst_update_pmtu_no_confirm(skb2, rel_info);
645 	}
646 
647 	icmp_send(skb2, rel_type, rel_code, htonl(rel_info));
648 
649 out:
650 	kfree_skb(skb2);
651 	return 0;
652 }
653 
654 static int
ip6ip6_err(struct sk_buff * skb,struct inet6_skb_parm * opt,u8 type,u8 code,int offset,__be32 info)655 ip6ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
656 	   u8 type, u8 code, int offset, __be32 info)
657 {
658 	__u32 rel_info = ntohl(info);
659 	int err, rel_msg = 0;
660 	u8 rel_type = type;
661 	u8 rel_code = code;
662 
663 	err = ip6_tnl_err(skb, IPPROTO_IPV6, opt, &rel_type, &rel_code,
664 			  &rel_msg, &rel_info, offset);
665 	if (err < 0)
666 		return err;
667 
668 	if (rel_msg && pskb_may_pull(skb, offset + sizeof(struct ipv6hdr))) {
669 		struct rt6_info *rt;
670 		struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
671 
672 		if (!skb2)
673 			return 0;
674 
675 		skb_dst_drop(skb2);
676 		skb_pull(skb2, offset);
677 		skb_reset_network_header(skb2);
678 
679 		/* Try to guess incoming interface */
680 		rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr,
681 				NULL, 0, skb2, 0);
682 
683 		if (rt && rt->dst.dev)
684 			skb2->dev = rt->dst.dev;
685 
686 		icmpv6_send(skb2, rel_type, rel_code, rel_info);
687 
688 		ip6_rt_put(rt);
689 
690 		kfree_skb(skb2);
691 	}
692 
693 	return 0;
694 }
695 
696 static int
mplsip6_err(struct sk_buff * skb,struct inet6_skb_parm * opt,u8 type,u8 code,int offset,__be32 info)697 mplsip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
698 	    u8 type, u8 code, int offset, __be32 info)
699 {
700 	__u32 rel_info = ntohl(info);
701 	int err, rel_msg = 0;
702 	u8 rel_type = type;
703 	u8 rel_code = code;
704 
705 	err = ip6_tnl_err(skb, IPPROTO_MPLS, opt, &rel_type, &rel_code,
706 			  &rel_msg, &rel_info, offset);
707 	return err;
708 }
709 
ip4ip6_dscp_ecn_decapsulate(const struct ip6_tnl * t,const struct ipv6hdr * ipv6h,struct sk_buff * skb)710 static int ip4ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
711 				       const struct ipv6hdr *ipv6h,
712 				       struct sk_buff *skb)
713 {
714 	__u8 dsfield = ipv6_get_dsfield(ipv6h) & ~INET_ECN_MASK;
715 
716 	if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
717 		ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, dsfield);
718 
719 	return IP6_ECN_decapsulate(ipv6h, skb);
720 }
721 
ip6ip6_dscp_ecn_decapsulate(const struct ip6_tnl * t,const struct ipv6hdr * ipv6h,struct sk_buff * skb)722 static int ip6ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
723 				       const struct ipv6hdr *ipv6h,
724 				       struct sk_buff *skb)
725 {
726 	if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
727 		ipv6_copy_dscp(ipv6_get_dsfield(ipv6h), ipv6_hdr(skb));
728 
729 	return IP6_ECN_decapsulate(ipv6h, skb);
730 }
731 
mplsip6_dscp_ecn_decapsulate(const struct ip6_tnl * t,const struct ipv6hdr * ipv6h,struct sk_buff * skb)732 static inline int mplsip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
733 					       const struct ipv6hdr *ipv6h,
734 					       struct sk_buff *skb)
735 {
736 	/* ECN is not supported in AF_MPLS */
737 	return 0;
738 }
739 
ip6_tnl_get_cap(struct ip6_tnl * t,const struct in6_addr * laddr,const struct in6_addr * raddr)740 __u32 ip6_tnl_get_cap(struct ip6_tnl *t,
741 			     const struct in6_addr *laddr,
742 			     const struct in6_addr *raddr)
743 {
744 	struct __ip6_tnl_parm *p = &t->parms;
745 	int ltype = ipv6_addr_type(laddr);
746 	int rtype = ipv6_addr_type(raddr);
747 	__u32 flags = 0;
748 
749 	if (ltype == IPV6_ADDR_ANY || rtype == IPV6_ADDR_ANY) {
750 		flags = IP6_TNL_F_CAP_PER_PACKET;
751 	} else if (ltype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
752 		   rtype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
753 		   !((ltype|rtype) & IPV6_ADDR_LOOPBACK) &&
754 		   (!((ltype|rtype) & IPV6_ADDR_LINKLOCAL) || p->link)) {
755 		if (ltype&IPV6_ADDR_UNICAST)
756 			flags |= IP6_TNL_F_CAP_XMIT;
757 		if (rtype&IPV6_ADDR_UNICAST)
758 			flags |= IP6_TNL_F_CAP_RCV;
759 	}
760 	return flags;
761 }
762 EXPORT_SYMBOL(ip6_tnl_get_cap);
763 
764 /* called with rcu_read_lock() */
ip6_tnl_rcv_ctl(struct ip6_tnl * t,const struct in6_addr * laddr,const struct in6_addr * raddr)765 int ip6_tnl_rcv_ctl(struct ip6_tnl *t,
766 				  const struct in6_addr *laddr,
767 				  const struct in6_addr *raddr)
768 {
769 	struct __ip6_tnl_parm *p = &t->parms;
770 	int ret = 0;
771 	struct net *net = t->net;
772 
773 	if ((p->flags & IP6_TNL_F_CAP_RCV) ||
774 	    ((p->flags & IP6_TNL_F_CAP_PER_PACKET) &&
775 	     (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_RCV))) {
776 		struct net_device *ldev = NULL;
777 
778 		if (p->link)
779 			ldev = dev_get_by_index_rcu(net, p->link);
780 
781 		if ((ipv6_addr_is_multicast(laddr) ||
782 		     likely(ipv6_chk_addr_and_flags(net, laddr, ldev, false,
783 						    0, IFA_F_TENTATIVE))) &&
784 		    ((p->flags & IP6_TNL_F_ALLOW_LOCAL_REMOTE) ||
785 		     likely(!ipv6_chk_addr_and_flags(net, raddr, ldev, true,
786 						     0, IFA_F_TENTATIVE))))
787 			ret = 1;
788 	}
789 	return ret;
790 }
791 EXPORT_SYMBOL_GPL(ip6_tnl_rcv_ctl);
792 
__ip6_tnl_rcv(struct ip6_tnl * tunnel,struct sk_buff * skb,const struct tnl_ptk_info * tpi,struct metadata_dst * tun_dst,int (* dscp_ecn_decapsulate)(const struct ip6_tnl * t,const struct ipv6hdr * ipv6h,struct sk_buff * skb),bool log_ecn_err)793 static int __ip6_tnl_rcv(struct ip6_tnl *tunnel, struct sk_buff *skb,
794 			 const struct tnl_ptk_info *tpi,
795 			 struct metadata_dst *tun_dst,
796 			 int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
797 						const struct ipv6hdr *ipv6h,
798 						struct sk_buff *skb),
799 			 bool log_ecn_err)
800 {
801 	const struct ipv6hdr *ipv6h;
802 	int nh, err;
803 
804 	if (test_bit(IP_TUNNEL_CSUM_BIT, tunnel->parms.i_flags) !=
805 	    test_bit(IP_TUNNEL_CSUM_BIT, tpi->flags)) {
806 		DEV_STATS_INC(tunnel->dev, rx_crc_errors);
807 		DEV_STATS_INC(tunnel->dev, rx_errors);
808 		goto drop;
809 	}
810 
811 	if (test_bit(IP_TUNNEL_SEQ_BIT, tunnel->parms.i_flags)) {
812 		if (!test_bit(IP_TUNNEL_SEQ_BIT, tpi->flags) ||
813 		    (tunnel->i_seqno &&
814 		     (s32)(ntohl(tpi->seq) - tunnel->i_seqno) < 0)) {
815 			DEV_STATS_INC(tunnel->dev, rx_fifo_errors);
816 			DEV_STATS_INC(tunnel->dev, rx_errors);
817 			goto drop;
818 		}
819 		tunnel->i_seqno = ntohl(tpi->seq) + 1;
820 	}
821 
822 	skb->protocol = tpi->proto;
823 
824 	/* Warning: All skb pointers will be invalidated! */
825 	if (tunnel->dev->type == ARPHRD_ETHER) {
826 		if (!pskb_may_pull(skb, ETH_HLEN)) {
827 			DEV_STATS_INC(tunnel->dev, rx_length_errors);
828 			DEV_STATS_INC(tunnel->dev, rx_errors);
829 			goto drop;
830 		}
831 
832 		skb->protocol = eth_type_trans(skb, tunnel->dev);
833 		skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
834 	} else {
835 		skb->dev = tunnel->dev;
836 		skb_reset_mac_header(skb);
837 	}
838 
839 	/* Save offset of outer header relative to skb->head,
840 	 * because we are going to reset the network header to the inner header
841 	 * and might change skb->head.
842 	 */
843 	nh = skb_network_header(skb) - skb->head;
844 
845 	skb_reset_network_header(skb);
846 
847 	if (!pskb_inet_may_pull(skb)) {
848 		DEV_STATS_INC(tunnel->dev, rx_length_errors);
849 		DEV_STATS_INC(tunnel->dev, rx_errors);
850 		goto drop;
851 	}
852 
853 	/* Get the outer header. */
854 	ipv6h = (struct ipv6hdr *)(skb->head + nh);
855 
856 	memset(skb->cb, 0, sizeof(struct inet6_skb_parm));
857 
858 	__skb_tunnel_rx(skb, tunnel->dev, tunnel->net);
859 
860 	err = dscp_ecn_decapsulate(tunnel, ipv6h, skb);
861 	if (unlikely(err)) {
862 		if (log_ecn_err)
863 			net_info_ratelimited("non-ECT from %pI6 with DS=%#x\n",
864 					     &ipv6h->saddr,
865 					     ipv6_get_dsfield(ipv6h));
866 		if (err > 1) {
867 			DEV_STATS_INC(tunnel->dev, rx_frame_errors);
868 			DEV_STATS_INC(tunnel->dev, rx_errors);
869 			goto drop;
870 		}
871 	}
872 
873 	dev_sw_netstats_rx_add(tunnel->dev, skb->len);
874 
875 	skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(tunnel->dev)));
876 
877 	if (tun_dst)
878 		skb_dst_set(skb, (struct dst_entry *)tun_dst);
879 
880 	gro_cells_receive(&tunnel->gro_cells, skb);
881 	return 0;
882 
883 drop:
884 	if (tun_dst)
885 		dst_release((struct dst_entry *)tun_dst);
886 	kfree_skb(skb);
887 	return 0;
888 }
889 
ip6_tnl_rcv(struct ip6_tnl * t,struct sk_buff * skb,const struct tnl_ptk_info * tpi,struct metadata_dst * tun_dst,bool log_ecn_err)890 int ip6_tnl_rcv(struct ip6_tnl *t, struct sk_buff *skb,
891 		const struct tnl_ptk_info *tpi,
892 		struct metadata_dst *tun_dst,
893 		bool log_ecn_err)
894 {
895 	int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
896 				    const struct ipv6hdr *ipv6h,
897 				    struct sk_buff *skb);
898 
899 	dscp_ecn_decapsulate = ip6ip6_dscp_ecn_decapsulate;
900 	if (tpi->proto == htons(ETH_P_IP))
901 		dscp_ecn_decapsulate = ip4ip6_dscp_ecn_decapsulate;
902 
903 	return __ip6_tnl_rcv(t, skb, tpi, tun_dst, dscp_ecn_decapsulate,
904 			     log_ecn_err);
905 }
906 EXPORT_SYMBOL(ip6_tnl_rcv);
907 
908 static const struct tnl_ptk_info tpi_v6 = {
909 	/* no tunnel info required for ipxip6. */
910 	.proto = htons(ETH_P_IPV6),
911 };
912 
913 static const struct tnl_ptk_info tpi_v4 = {
914 	/* no tunnel info required for ipxip6. */
915 	.proto = htons(ETH_P_IP),
916 };
917 
918 static const struct tnl_ptk_info tpi_mpls = {
919 	/* no tunnel info required for mplsip6. */
920 	.proto = htons(ETH_P_MPLS_UC),
921 };
922 
ipxip6_rcv(struct sk_buff * skb,u8 ipproto,const struct tnl_ptk_info * tpi,int (* dscp_ecn_decapsulate)(const struct ip6_tnl * t,const struct ipv6hdr * ipv6h,struct sk_buff * skb))923 static int ipxip6_rcv(struct sk_buff *skb, u8 ipproto,
924 		      const struct tnl_ptk_info *tpi,
925 		      int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
926 						  const struct ipv6hdr *ipv6h,
927 						  struct sk_buff *skb))
928 {
929 	struct ip6_tnl *t;
930 	const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
931 	struct metadata_dst *tun_dst = NULL;
932 	int ret = -1;
933 
934 	rcu_read_lock();
935 	t = ip6_tnl_lookup(dev_net(skb->dev), skb->dev->ifindex, &ipv6h->saddr, &ipv6h->daddr);
936 
937 	if (t) {
938 		u8 tproto = READ_ONCE(t->parms.proto);
939 
940 		if (tproto != ipproto && tproto != 0)
941 			goto drop;
942 		if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
943 			goto drop;
944 		ipv6h = ipv6_hdr(skb);
945 		if (!ip6_tnl_rcv_ctl(t, &ipv6h->daddr, &ipv6h->saddr))
946 			goto drop;
947 		if (iptunnel_pull_header(skb, 0, tpi->proto, false))
948 			goto drop;
949 		if (t->parms.collect_md) {
950 			IP_TUNNEL_DECLARE_FLAGS(flags) = { };
951 
952 			tun_dst = ipv6_tun_rx_dst(skb, flags, 0, 0);
953 			if (!tun_dst)
954 				goto drop;
955 		}
956 		ret = __ip6_tnl_rcv(t, skb, tpi, tun_dst, dscp_ecn_decapsulate,
957 				    log_ecn_error);
958 	}
959 
960 	rcu_read_unlock();
961 
962 	return ret;
963 
964 drop:
965 	rcu_read_unlock();
966 	kfree_skb(skb);
967 	return 0;
968 }
969 
ip4ip6_rcv(struct sk_buff * skb)970 static int ip4ip6_rcv(struct sk_buff *skb)
971 {
972 	return ipxip6_rcv(skb, IPPROTO_IPIP, &tpi_v4,
973 			  ip4ip6_dscp_ecn_decapsulate);
974 }
975 
ip6ip6_rcv(struct sk_buff * skb)976 static int ip6ip6_rcv(struct sk_buff *skb)
977 {
978 	return ipxip6_rcv(skb, IPPROTO_IPV6, &tpi_v6,
979 			  ip6ip6_dscp_ecn_decapsulate);
980 }
981 
mplsip6_rcv(struct sk_buff * skb)982 static int mplsip6_rcv(struct sk_buff *skb)
983 {
984 	return ipxip6_rcv(skb, IPPROTO_MPLS, &tpi_mpls,
985 			  mplsip6_dscp_ecn_decapsulate);
986 }
987 
988 struct ipv6_tel_txoption {
989 	struct ipv6_txoptions ops;
990 	__u8 dst_opt[8];
991 };
992 
init_tel_txopt(struct ipv6_tel_txoption * opt,__u8 encap_limit)993 static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit)
994 {
995 	memset(opt, 0, sizeof(struct ipv6_tel_txoption));
996 
997 	opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT;
998 	opt->dst_opt[3] = 1;
999 	opt->dst_opt[4] = encap_limit;
1000 	opt->dst_opt[5] = IPV6_TLV_PADN;
1001 	opt->dst_opt[6] = 1;
1002 
1003 	opt->ops.dst1opt = (struct ipv6_opt_hdr *) opt->dst_opt;
1004 	opt->ops.opt_nflen = 8;
1005 }
1006 
1007 /**
1008  * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
1009  *   @t: the outgoing tunnel device
1010  *   @hdr: IPv6 header from the incoming packet
1011  *
1012  * Description:
1013  *   Avoid trivial tunneling loop by checking that tunnel exit-point
1014  *   doesn't match source of incoming packet.
1015  *
1016  * Return:
1017  *   1 if conflict,
1018  *   0 else
1019  **/
1020 
1021 static inline bool
ip6_tnl_addr_conflict(const struct ip6_tnl * t,const struct ipv6hdr * hdr)1022 ip6_tnl_addr_conflict(const struct ip6_tnl *t, const struct ipv6hdr *hdr)
1023 {
1024 	return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
1025 }
1026 
ip6_tnl_xmit_ctl(struct ip6_tnl * t,const struct in6_addr * laddr,const struct in6_addr * raddr)1027 int ip6_tnl_xmit_ctl(struct ip6_tnl *t,
1028 		     const struct in6_addr *laddr,
1029 		     const struct in6_addr *raddr)
1030 {
1031 	struct __ip6_tnl_parm *p = &t->parms;
1032 	int ret = 0;
1033 	struct net *net = t->net;
1034 
1035 	if (t->parms.collect_md)
1036 		return 1;
1037 
1038 	if ((p->flags & IP6_TNL_F_CAP_XMIT) ||
1039 	    ((p->flags & IP6_TNL_F_CAP_PER_PACKET) &&
1040 	     (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_XMIT))) {
1041 		struct net_device *ldev = NULL;
1042 
1043 		rcu_read_lock();
1044 		if (p->link)
1045 			ldev = dev_get_by_index_rcu(net, p->link);
1046 
1047 		if (unlikely(!ipv6_chk_addr_and_flags(net, laddr, ldev, false,
1048 						      0, IFA_F_TENTATIVE)))
1049 			pr_warn_ratelimited("%s xmit: Local address not yet configured!\n",
1050 					    p->name);
1051 		else if (!(p->flags & IP6_TNL_F_ALLOW_LOCAL_REMOTE) &&
1052 			 !ipv6_addr_is_multicast(raddr) &&
1053 			 unlikely(ipv6_chk_addr_and_flags(net, raddr, ldev,
1054 							  true, 0, IFA_F_TENTATIVE)))
1055 			pr_warn_ratelimited("%s xmit: Routing loop! Remote address found on this node!\n",
1056 					    p->name);
1057 		else
1058 			ret = 1;
1059 		rcu_read_unlock();
1060 	}
1061 	return ret;
1062 }
1063 EXPORT_SYMBOL_GPL(ip6_tnl_xmit_ctl);
1064 
1065 /**
1066  * ip6_tnl_xmit - encapsulate packet and send
1067  *   @skb: the outgoing socket buffer
1068  *   @dev: the outgoing tunnel device
1069  *   @dsfield: dscp code for outer header
1070  *   @fl6: flow of tunneled packet
1071  *   @encap_limit: encapsulation limit
1072  *   @pmtu: Path MTU is stored if packet is too big
1073  *   @proto: next header value
1074  *
1075  * Description:
1076  *   Build new header and do some sanity checks on the packet before sending
1077  *   it.
1078  *
1079  * Return:
1080  *   0 on success
1081  *   -1 fail
1082  *   %-EMSGSIZE message too big. return mtu in this case.
1083  **/
1084 
ip6_tnl_xmit(struct sk_buff * skb,struct net_device * dev,__u8 dsfield,struct flowi6 * fl6,int encap_limit,__u32 * pmtu,__u8 proto)1085 int ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev, __u8 dsfield,
1086 		 struct flowi6 *fl6, int encap_limit, __u32 *pmtu,
1087 		 __u8 proto)
1088 {
1089 	struct ip6_tnl *t = netdev_priv(dev);
1090 	struct net *net = t->net;
1091 	struct ipv6hdr *ipv6h;
1092 	struct ipv6_tel_txoption opt;
1093 	struct dst_entry *dst = NULL, *ndst = NULL;
1094 	struct net_device *tdev;
1095 	int mtu;
1096 	unsigned int eth_hlen = t->dev->type == ARPHRD_ETHER ? ETH_HLEN : 0;
1097 	unsigned int psh_hlen = sizeof(struct ipv6hdr) + t->encap_hlen;
1098 	unsigned int max_headroom = psh_hlen;
1099 	__be16 payload_protocol;
1100 	bool use_cache = false;
1101 	u8 hop_limit;
1102 	int err = -1;
1103 
1104 	payload_protocol = skb_protocol(skb, true);
1105 
1106 	if (t->parms.collect_md) {
1107 		hop_limit = skb_tunnel_info(skb)->key.ttl;
1108 		goto route_lookup;
1109 	} else {
1110 		hop_limit = t->parms.hop_limit;
1111 	}
1112 
1113 	/* NBMA tunnel */
1114 	if (ipv6_addr_any(&t->parms.raddr)) {
1115 		if (payload_protocol == htons(ETH_P_IPV6)) {
1116 			struct in6_addr *addr6;
1117 			struct neighbour *neigh;
1118 			int addr_type;
1119 
1120 			if (!skb_dst(skb))
1121 				goto tx_err_link_failure;
1122 
1123 			neigh = dst_neigh_lookup(skb_dst(skb),
1124 						 &ipv6_hdr(skb)->daddr);
1125 			if (!neigh)
1126 				goto tx_err_link_failure;
1127 
1128 			addr6 = (struct in6_addr *)&neigh->primary_key;
1129 			addr_type = ipv6_addr_type(addr6);
1130 
1131 			if (addr_type == IPV6_ADDR_ANY)
1132 				addr6 = &ipv6_hdr(skb)->daddr;
1133 
1134 			memcpy(&fl6->daddr, addr6, sizeof(fl6->daddr));
1135 			neigh_release(neigh);
1136 		} else if (payload_protocol == htons(ETH_P_IP)) {
1137 			const struct rtable *rt = skb_rtable(skb);
1138 
1139 			if (!rt)
1140 				goto tx_err_link_failure;
1141 
1142 			if (rt->rt_gw_family == AF_INET6)
1143 				memcpy(&fl6->daddr, &rt->rt_gw6, sizeof(fl6->daddr));
1144 		}
1145 	} else if (t->parms.proto != 0 && !(t->parms.flags &
1146 					    (IP6_TNL_F_USE_ORIG_TCLASS |
1147 					     IP6_TNL_F_USE_ORIG_FWMARK))) {
1148 		/* enable the cache only if neither the outer protocol nor the
1149 		 * routing decision depends on the current inner header value
1150 		 */
1151 		use_cache = true;
1152 	}
1153 
1154 	if (use_cache)
1155 		dst = dst_cache_get(&t->dst_cache);
1156 
1157 	if (!ip6_tnl_xmit_ctl(t, &fl6->saddr, &fl6->daddr))
1158 		goto tx_err_link_failure;
1159 
1160 	if (!dst) {
1161 route_lookup:
1162 		/* add dsfield to flowlabel for route lookup */
1163 		fl6->flowlabel = ip6_make_flowinfo(dsfield, fl6->flowlabel);
1164 
1165 		dst = ip6_route_output(net, NULL, fl6);
1166 
1167 		if (dst->error)
1168 			goto tx_err_link_failure;
1169 		dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), NULL, 0);
1170 		if (IS_ERR(dst)) {
1171 			err = PTR_ERR(dst);
1172 			dst = NULL;
1173 			goto tx_err_link_failure;
1174 		}
1175 		if (t->parms.collect_md && ipv6_addr_any(&fl6->saddr) &&
1176 		    ipv6_dev_get_saddr(net, ip6_dst_idev(dst)->dev,
1177 				       &fl6->daddr, 0, &fl6->saddr))
1178 			goto tx_err_link_failure;
1179 		ndst = dst;
1180 	}
1181 
1182 	tdev = dst->dev;
1183 
1184 	if (tdev == dev) {
1185 		DEV_STATS_INC(dev, collisions);
1186 		net_warn_ratelimited("%s: Local routing loop detected!\n",
1187 				     t->parms.name);
1188 		goto tx_err_dst_release;
1189 	}
1190 	mtu = dst_mtu(dst) - eth_hlen - psh_hlen - t->tun_hlen;
1191 	if (encap_limit >= 0) {
1192 		max_headroom += 8;
1193 		mtu -= 8;
1194 	}
1195 	mtu = max(mtu, skb->protocol == htons(ETH_P_IPV6) ?
1196 		       IPV6_MIN_MTU : IPV4_MIN_MTU);
1197 
1198 	skb_dst_update_pmtu_no_confirm(skb, mtu);
1199 	if (skb->len - t->tun_hlen - eth_hlen > mtu && !skb_is_gso(skb)) {
1200 		*pmtu = mtu;
1201 		err = -EMSGSIZE;
1202 		goto tx_err_dst_release;
1203 	}
1204 
1205 	if (t->err_count > 0) {
1206 		if (time_before(jiffies,
1207 				t->err_time + IP6TUNNEL_ERR_TIMEO)) {
1208 			t->err_count--;
1209 
1210 			dst_link_failure(skb);
1211 		} else {
1212 			t->err_count = 0;
1213 		}
1214 	}
1215 
1216 	skb_scrub_packet(skb, !net_eq(t->net, dev_net(dev)));
1217 
1218 	/*
1219 	 * Okay, now see if we can stuff it in the buffer as-is.
1220 	 */
1221 	max_headroom += LL_RESERVED_SPACE(tdev);
1222 
1223 	if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
1224 	    (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
1225 		struct sk_buff *new_skb;
1226 
1227 		new_skb = skb_realloc_headroom(skb, max_headroom);
1228 		if (!new_skb)
1229 			goto tx_err_dst_release;
1230 
1231 		if (skb->sk)
1232 			skb_set_owner_w(new_skb, skb->sk);
1233 		consume_skb(skb);
1234 		skb = new_skb;
1235 	}
1236 
1237 	if (t->parms.collect_md) {
1238 		if (t->encap.type != TUNNEL_ENCAP_NONE)
1239 			goto tx_err_dst_release;
1240 	} else {
1241 		if (use_cache && ndst)
1242 			dst_cache_set_ip6(&t->dst_cache, ndst, &fl6->saddr);
1243 	}
1244 	skb_dst_set(skb, dst);
1245 
1246 	if (hop_limit == 0) {
1247 		if (payload_protocol == htons(ETH_P_IP))
1248 			hop_limit = ip_hdr(skb)->ttl;
1249 		else if (payload_protocol == htons(ETH_P_IPV6))
1250 			hop_limit = ipv6_hdr(skb)->hop_limit;
1251 		else
1252 			hop_limit = ip6_dst_hoplimit(dst);
1253 	}
1254 
1255 	/* Calculate max headroom for all the headers and adjust
1256 	 * needed_headroom if necessary.
1257 	 */
1258 	max_headroom = LL_RESERVED_SPACE(dst->dev) + sizeof(struct ipv6hdr)
1259 			+ dst->header_len + t->hlen;
1260 	if (max_headroom > READ_ONCE(dev->needed_headroom))
1261 		WRITE_ONCE(dev->needed_headroom, max_headroom);
1262 
1263 	err = ip6_tnl_encap(skb, t, &proto, fl6);
1264 	if (err)
1265 		return err;
1266 
1267 	if (encap_limit >= 0) {
1268 		init_tel_txopt(&opt, encap_limit);
1269 		ipv6_push_frag_opts(skb, &opt.ops, &proto);
1270 	}
1271 
1272 	skb_push(skb, sizeof(struct ipv6hdr));
1273 	skb_reset_network_header(skb);
1274 	ipv6h = ipv6_hdr(skb);
1275 	ip6_flow_hdr(ipv6h, dsfield,
1276 		     ip6_make_flowlabel(net, skb, fl6->flowlabel, true, fl6));
1277 	ipv6h->hop_limit = hop_limit;
1278 	ipv6h->nexthdr = proto;
1279 	ipv6h->saddr = fl6->saddr;
1280 	ipv6h->daddr = fl6->daddr;
1281 	ip6tunnel_xmit(NULL, skb, dev);
1282 	return 0;
1283 tx_err_link_failure:
1284 	DEV_STATS_INC(dev, tx_carrier_errors);
1285 	dst_link_failure(skb);
1286 tx_err_dst_release:
1287 	dst_release(dst);
1288 	return err;
1289 }
1290 EXPORT_SYMBOL(ip6_tnl_xmit);
1291 
1292 static inline int
ipxip6_tnl_xmit(struct sk_buff * skb,struct net_device * dev,u8 protocol)1293 ipxip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev,
1294 		u8 protocol)
1295 {
1296 	struct ip6_tnl *t = netdev_priv(dev);
1297 	struct ipv6hdr *ipv6h;
1298 	const struct iphdr  *iph;
1299 	int encap_limit = -1;
1300 	__u16 offset;
1301 	struct flowi6 fl6;
1302 	__u8 dsfield, orig_dsfield;
1303 	__u32 mtu;
1304 	u8 tproto;
1305 	int err;
1306 
1307 	tproto = READ_ONCE(t->parms.proto);
1308 	if (tproto != protocol && tproto != 0)
1309 		return -1;
1310 
1311 	if (t->parms.collect_md) {
1312 		struct ip_tunnel_info *tun_info;
1313 		const struct ip_tunnel_key *key;
1314 
1315 		tun_info = skb_tunnel_info(skb);
1316 		if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
1317 			     ip_tunnel_info_af(tun_info) != AF_INET6))
1318 			return -1;
1319 		key = &tun_info->key;
1320 		memset(&fl6, 0, sizeof(fl6));
1321 		fl6.flowi6_proto = protocol;
1322 		fl6.saddr = key->u.ipv6.src;
1323 		fl6.daddr = key->u.ipv6.dst;
1324 		fl6.flowlabel = key->label;
1325 		dsfield =  key->tos;
1326 		switch (protocol) {
1327 		case IPPROTO_IPIP:
1328 			iph = ip_hdr(skb);
1329 			orig_dsfield = ipv4_get_dsfield(iph);
1330 			break;
1331 		case IPPROTO_IPV6:
1332 			ipv6h = ipv6_hdr(skb);
1333 			orig_dsfield = ipv6_get_dsfield(ipv6h);
1334 			break;
1335 		default:
1336 			orig_dsfield = dsfield;
1337 			break;
1338 		}
1339 	} else {
1340 		if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1341 			encap_limit = t->parms.encap_limit;
1342 		if (protocol == IPPROTO_IPV6) {
1343 			offset = ip6_tnl_parse_tlv_enc_lim(skb,
1344 						skb_network_header(skb));
1345 			/* ip6_tnl_parse_tlv_enc_lim() might have
1346 			 * reallocated skb->head
1347 			 */
1348 			if (offset > 0) {
1349 				struct ipv6_tlv_tnl_enc_lim *tel;
1350 
1351 				tel = (void *)&skb_network_header(skb)[offset];
1352 				if (tel->encap_limit == 0) {
1353 					icmpv6_ndo_send(skb, ICMPV6_PARAMPROB,
1354 							ICMPV6_HDR_FIELD, offset + 2);
1355 					return -1;
1356 				}
1357 				encap_limit = tel->encap_limit - 1;
1358 			}
1359 		}
1360 
1361 		memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
1362 		fl6.flowi6_proto = protocol;
1363 
1364 		if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
1365 			fl6.flowi6_mark = skb->mark;
1366 		else
1367 			fl6.flowi6_mark = t->parms.fwmark;
1368 		switch (protocol) {
1369 		case IPPROTO_IPIP:
1370 			iph = ip_hdr(skb);
1371 			orig_dsfield = ipv4_get_dsfield(iph);
1372 			if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1373 				dsfield = orig_dsfield;
1374 			else
1375 				dsfield = ip6_tclass(t->parms.flowinfo);
1376 			break;
1377 		case IPPROTO_IPV6:
1378 			ipv6h = ipv6_hdr(skb);
1379 			orig_dsfield = ipv6_get_dsfield(ipv6h);
1380 			if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1381 				dsfield = orig_dsfield;
1382 			else
1383 				dsfield = ip6_tclass(t->parms.flowinfo);
1384 			if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
1385 				fl6.flowlabel |= ip6_flowlabel(ipv6h);
1386 			break;
1387 		default:
1388 			orig_dsfield = dsfield = ip6_tclass(t->parms.flowinfo);
1389 			break;
1390 		}
1391 	}
1392 
1393 	fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
1394 	dsfield = INET_ECN_encapsulate(dsfield, orig_dsfield);
1395 
1396 	if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP6))
1397 		return -1;
1398 
1399 	skb_set_inner_ipproto(skb, protocol);
1400 
1401 	err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
1402 			   protocol);
1403 	if (err != 0) {
1404 		/* XXX: send ICMP error even if DF is not set. */
1405 		if (err == -EMSGSIZE)
1406 			switch (protocol) {
1407 			case IPPROTO_IPIP:
1408 				icmp_ndo_send(skb, ICMP_DEST_UNREACH,
1409 					      ICMP_FRAG_NEEDED, htonl(mtu));
1410 				break;
1411 			case IPPROTO_IPV6:
1412 				icmpv6_ndo_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
1413 				break;
1414 			default:
1415 				break;
1416 			}
1417 		return -1;
1418 	}
1419 
1420 	return 0;
1421 }
1422 
1423 static netdev_tx_t
ip6_tnl_start_xmit(struct sk_buff * skb,struct net_device * dev)1424 ip6_tnl_start_xmit(struct sk_buff *skb, struct net_device *dev)
1425 {
1426 	struct ip6_tnl *t = netdev_priv(dev);
1427 	u8 ipproto;
1428 	int ret;
1429 
1430 	if (!pskb_inet_may_pull(skb))
1431 		goto tx_err;
1432 
1433 	switch (skb->protocol) {
1434 	case htons(ETH_P_IP):
1435 		ipproto = IPPROTO_IPIP;
1436 		break;
1437 	case htons(ETH_P_IPV6):
1438 		if (ip6_tnl_addr_conflict(t, ipv6_hdr(skb)))
1439 			goto tx_err;
1440 		ipproto = IPPROTO_IPV6;
1441 		break;
1442 	case htons(ETH_P_MPLS_UC):
1443 		ipproto = IPPROTO_MPLS;
1444 		break;
1445 	default:
1446 		goto tx_err;
1447 	}
1448 
1449 	ret = ipxip6_tnl_xmit(skb, dev, ipproto);
1450 	if (ret < 0)
1451 		goto tx_err;
1452 
1453 	return NETDEV_TX_OK;
1454 
1455 tx_err:
1456 	DEV_STATS_INC(dev, tx_errors);
1457 	DEV_STATS_INC(dev, tx_dropped);
1458 	kfree_skb(skb);
1459 	return NETDEV_TX_OK;
1460 }
1461 
ip6_tnl_link_config(struct ip6_tnl * t)1462 static void ip6_tnl_link_config(struct ip6_tnl *t)
1463 {
1464 	struct net_device *dev = t->dev;
1465 	struct net_device *tdev = NULL;
1466 	struct __ip6_tnl_parm *p = &t->parms;
1467 	struct flowi6 *fl6 = &t->fl.u.ip6;
1468 	int t_hlen;
1469 	int mtu;
1470 
1471 	__dev_addr_set(dev, &p->laddr, sizeof(struct in6_addr));
1472 	memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
1473 
1474 	/* Set up flowi template */
1475 	fl6->saddr = p->laddr;
1476 	fl6->daddr = p->raddr;
1477 	fl6->flowi6_oif = p->link;
1478 	fl6->flowlabel = 0;
1479 
1480 	if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
1481 		fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
1482 	if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
1483 		fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
1484 
1485 	p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
1486 	p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
1487 
1488 	if (p->flags&IP6_TNL_F_CAP_XMIT && p->flags&IP6_TNL_F_CAP_RCV)
1489 		dev->flags |= IFF_POINTOPOINT;
1490 	else
1491 		dev->flags &= ~IFF_POINTOPOINT;
1492 
1493 	t->tun_hlen = 0;
1494 	t->hlen = t->encap_hlen + t->tun_hlen;
1495 	t_hlen = t->hlen + sizeof(struct ipv6hdr);
1496 
1497 	if (p->flags & IP6_TNL_F_CAP_XMIT) {
1498 		int strict = (ipv6_addr_type(&p->raddr) &
1499 			      (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
1500 
1501 		struct rt6_info *rt = rt6_lookup(t->net,
1502 						 &p->raddr, &p->laddr,
1503 						 p->link, NULL, strict);
1504 		if (rt) {
1505 			tdev = rt->dst.dev;
1506 			ip6_rt_put(rt);
1507 		}
1508 
1509 		if (!tdev && p->link)
1510 			tdev = __dev_get_by_index(t->net, p->link);
1511 
1512 		if (tdev) {
1513 			dev->needed_headroom = tdev->hard_header_len +
1514 				tdev->needed_headroom + t_hlen;
1515 			mtu = min_t(unsigned int, tdev->mtu, IP6_MAX_MTU);
1516 
1517 			mtu = mtu - t_hlen;
1518 			if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1519 				mtu -= 8;
1520 
1521 			if (mtu < IPV6_MIN_MTU)
1522 				mtu = IPV6_MIN_MTU;
1523 			WRITE_ONCE(dev->mtu, mtu);
1524 		}
1525 	}
1526 }
1527 
1528 /**
1529  * ip6_tnl_change - update the tunnel parameters
1530  *   @t: tunnel to be changed
1531  *   @p: tunnel configuration parameters
1532  *
1533  * Description:
1534  *   ip6_tnl_change() updates the tunnel parameters
1535  **/
1536 
1537 static void
ip6_tnl_change(struct ip6_tnl * t,const struct __ip6_tnl_parm * p)1538 ip6_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p)
1539 {
1540 	t->parms.laddr = p->laddr;
1541 	t->parms.raddr = p->raddr;
1542 	t->parms.flags = p->flags;
1543 	t->parms.hop_limit = p->hop_limit;
1544 	t->parms.encap_limit = p->encap_limit;
1545 	t->parms.flowinfo = p->flowinfo;
1546 	t->parms.link = p->link;
1547 	t->parms.proto = p->proto;
1548 	t->parms.fwmark = p->fwmark;
1549 	dst_cache_reset(&t->dst_cache);
1550 	ip6_tnl_link_config(t);
1551 }
1552 
ip6_tnl_update(struct ip6_tnl * t,struct __ip6_tnl_parm * p)1553 static void ip6_tnl_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
1554 {
1555 	struct net *net = t->net;
1556 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1557 
1558 	ip6_tnl_unlink(ip6n, t);
1559 	synchronize_net();
1560 	ip6_tnl_change(t, p);
1561 	ip6_tnl_link(ip6n, t);
1562 	netdev_state_change(t->dev);
1563 }
1564 
ip6_tnl0_update(struct ip6_tnl * t,struct __ip6_tnl_parm * p)1565 static void ip6_tnl0_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
1566 {
1567 	/* for default tnl0 device allow to change only the proto */
1568 	t->parms.proto = p->proto;
1569 	netdev_state_change(t->dev);
1570 }
1571 
1572 static void
ip6_tnl_parm_from_user(struct __ip6_tnl_parm * p,const struct ip6_tnl_parm * u)1573 ip6_tnl_parm_from_user(struct __ip6_tnl_parm *p, const struct ip6_tnl_parm *u)
1574 {
1575 	p->laddr = u->laddr;
1576 	p->raddr = u->raddr;
1577 	p->flags = u->flags;
1578 	p->hop_limit = u->hop_limit;
1579 	p->encap_limit = u->encap_limit;
1580 	p->flowinfo = u->flowinfo;
1581 	p->link = u->link;
1582 	p->proto = u->proto;
1583 	memcpy(p->name, u->name, sizeof(u->name));
1584 }
1585 
1586 static void
ip6_tnl_parm_to_user(struct ip6_tnl_parm * u,const struct __ip6_tnl_parm * p)1587 ip6_tnl_parm_to_user(struct ip6_tnl_parm *u, const struct __ip6_tnl_parm *p)
1588 {
1589 	u->laddr = p->laddr;
1590 	u->raddr = p->raddr;
1591 	u->flags = p->flags;
1592 	u->hop_limit = p->hop_limit;
1593 	u->encap_limit = p->encap_limit;
1594 	u->flowinfo = p->flowinfo;
1595 	u->link = p->link;
1596 	u->proto = p->proto;
1597 	memcpy(u->name, p->name, sizeof(u->name));
1598 }
1599 
1600 /**
1601  * ip6_tnl_siocdevprivate - configure ipv6 tunnels from userspace
1602  *   @dev: virtual device associated with tunnel
1603  *   @ifr: unused
1604  *   @data: parameters passed from userspace
1605  *   @cmd: command to be performed
1606  *
1607  * Description:
1608  *   ip6_tnl_ioctl() is used for managing IPv6 tunnels
1609  *   from userspace.
1610  *
1611  *   The possible commands are the following:
1612  *     %SIOCGETTUNNEL: get tunnel parameters for device
1613  *     %SIOCADDTUNNEL: add tunnel matching given tunnel parameters
1614  *     %SIOCCHGTUNNEL: change tunnel parameters to those given
1615  *     %SIOCDELTUNNEL: delete tunnel
1616  *
1617  *   The fallback device "ip6tnl0", created during module
1618  *   initialization, can be used for creating other tunnel devices.
1619  *
1620  * Return:
1621  *   0 on success,
1622  *   %-EFAULT if unable to copy data to or from userspace,
1623  *   %-EPERM if current process hasn't %CAP_NET_ADMIN set
1624  *   %-EINVAL if passed tunnel parameters are invalid,
1625  *   %-EEXIST if changing a tunnel's parameters would cause a conflict
1626  *   %-ENODEV if attempting to change or delete a nonexisting device
1627  **/
1628 
1629 static int
ip6_tnl_siocdevprivate(struct net_device * dev,struct ifreq * ifr,void __user * data,int cmd)1630 ip6_tnl_siocdevprivate(struct net_device *dev, struct ifreq *ifr,
1631 		       void __user *data, int cmd)
1632 {
1633 	int err = 0;
1634 	struct ip6_tnl_parm p;
1635 	struct __ip6_tnl_parm p1;
1636 	struct ip6_tnl *t = netdev_priv(dev);
1637 	struct net *net = t->net;
1638 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1639 
1640 	memset(&p1, 0, sizeof(p1));
1641 
1642 	switch (cmd) {
1643 	case SIOCGETTUNNEL:
1644 		if (dev == ip6n->fb_tnl_dev) {
1645 			if (copy_from_user(&p, data, sizeof(p))) {
1646 				err = -EFAULT;
1647 				break;
1648 			}
1649 			ip6_tnl_parm_from_user(&p1, &p);
1650 			t = ip6_tnl_locate(net, &p1, 0);
1651 			if (IS_ERR(t))
1652 				t = netdev_priv(dev);
1653 		} else {
1654 			memset(&p, 0, sizeof(p));
1655 		}
1656 		ip6_tnl_parm_to_user(&p, &t->parms);
1657 		if (copy_to_user(data, &p, sizeof(p)))
1658 			err = -EFAULT;
1659 		break;
1660 	case SIOCADDTUNNEL:
1661 	case SIOCCHGTUNNEL:
1662 		err = -EPERM;
1663 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1664 			break;
1665 		err = -EFAULT;
1666 		if (copy_from_user(&p, data, sizeof(p)))
1667 			break;
1668 		err = -EINVAL;
1669 		if (p.proto != IPPROTO_IPV6 && p.proto != IPPROTO_IPIP &&
1670 		    p.proto != 0)
1671 			break;
1672 		ip6_tnl_parm_from_user(&p1, &p);
1673 		t = ip6_tnl_locate(net, &p1, cmd == SIOCADDTUNNEL);
1674 		if (cmd == SIOCCHGTUNNEL) {
1675 			if (!IS_ERR(t)) {
1676 				if (t->dev != dev) {
1677 					err = -EEXIST;
1678 					break;
1679 				}
1680 			} else
1681 				t = netdev_priv(dev);
1682 			if (dev == ip6n->fb_tnl_dev)
1683 				ip6_tnl0_update(t, &p1);
1684 			else
1685 				ip6_tnl_update(t, &p1);
1686 		}
1687 		if (!IS_ERR(t)) {
1688 			err = 0;
1689 			ip6_tnl_parm_to_user(&p, &t->parms);
1690 			if (copy_to_user(data, &p, sizeof(p)))
1691 				err = -EFAULT;
1692 
1693 		} else {
1694 			err = PTR_ERR(t);
1695 		}
1696 		break;
1697 	case SIOCDELTUNNEL:
1698 		err = -EPERM;
1699 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1700 			break;
1701 
1702 		if (dev == ip6n->fb_tnl_dev) {
1703 			err = -EFAULT;
1704 			if (copy_from_user(&p, data, sizeof(p)))
1705 				break;
1706 			err = -ENOENT;
1707 			ip6_tnl_parm_from_user(&p1, &p);
1708 			t = ip6_tnl_locate(net, &p1, 0);
1709 			if (IS_ERR(t))
1710 				break;
1711 			err = -EPERM;
1712 			if (t->dev == ip6n->fb_tnl_dev)
1713 				break;
1714 			dev = t->dev;
1715 		}
1716 		err = 0;
1717 		unregister_netdevice(dev);
1718 		break;
1719 	default:
1720 		err = -EINVAL;
1721 	}
1722 	return err;
1723 }
1724 
1725 /**
1726  * ip6_tnl_change_mtu - change mtu manually for tunnel device
1727  *   @dev: virtual device associated with tunnel
1728  *   @new_mtu: the new mtu
1729  *
1730  * Return:
1731  *   0 on success,
1732  *   %-EINVAL if mtu too small
1733  **/
1734 
ip6_tnl_change_mtu(struct net_device * dev,int new_mtu)1735 int ip6_tnl_change_mtu(struct net_device *dev, int new_mtu)
1736 {
1737 	struct ip6_tnl *tnl = netdev_priv(dev);
1738 	int t_hlen;
1739 
1740 	t_hlen = tnl->hlen + sizeof(struct ipv6hdr);
1741 	if (tnl->parms.proto == IPPROTO_IPV6) {
1742 		if (new_mtu < IPV6_MIN_MTU)
1743 			return -EINVAL;
1744 	} else {
1745 		if (new_mtu < ETH_MIN_MTU)
1746 			return -EINVAL;
1747 	}
1748 	if (tnl->parms.proto == IPPROTO_IPV6 || tnl->parms.proto == 0) {
1749 		if (new_mtu > IP6_MAX_MTU - dev->hard_header_len - t_hlen)
1750 			return -EINVAL;
1751 	} else {
1752 		if (new_mtu > IP_MAX_MTU - dev->hard_header_len - t_hlen)
1753 			return -EINVAL;
1754 	}
1755 	WRITE_ONCE(dev->mtu, new_mtu);
1756 	return 0;
1757 }
1758 EXPORT_SYMBOL(ip6_tnl_change_mtu);
1759 
ip6_tnl_get_iflink(const struct net_device * dev)1760 int ip6_tnl_get_iflink(const struct net_device *dev)
1761 {
1762 	struct ip6_tnl *t = netdev_priv(dev);
1763 
1764 	return READ_ONCE(t->parms.link);
1765 }
1766 EXPORT_SYMBOL(ip6_tnl_get_iflink);
1767 
ip6_tnl_encap_add_ops(const struct ip6_tnl_encap_ops * ops,unsigned int num)1768 int ip6_tnl_encap_add_ops(const struct ip6_tnl_encap_ops *ops,
1769 			  unsigned int num)
1770 {
1771 	if (num >= MAX_IPTUN_ENCAP_OPS)
1772 		return -ERANGE;
1773 
1774 	return !cmpxchg((const struct ip6_tnl_encap_ops **)
1775 			&ip6tun_encaps[num],
1776 			NULL, ops) ? 0 : -1;
1777 }
1778 EXPORT_SYMBOL(ip6_tnl_encap_add_ops);
1779 
ip6_tnl_encap_del_ops(const struct ip6_tnl_encap_ops * ops,unsigned int num)1780 int ip6_tnl_encap_del_ops(const struct ip6_tnl_encap_ops *ops,
1781 			  unsigned int num)
1782 {
1783 	int ret;
1784 
1785 	if (num >= MAX_IPTUN_ENCAP_OPS)
1786 		return -ERANGE;
1787 
1788 	ret = (cmpxchg((const struct ip6_tnl_encap_ops **)
1789 		       &ip6tun_encaps[num],
1790 		       ops, NULL) == ops) ? 0 : -1;
1791 
1792 	synchronize_net();
1793 
1794 	return ret;
1795 }
1796 EXPORT_SYMBOL(ip6_tnl_encap_del_ops);
1797 
ip6_tnl_encap_setup(struct ip6_tnl * t,struct ip_tunnel_encap * ipencap)1798 int ip6_tnl_encap_setup(struct ip6_tnl *t,
1799 			struct ip_tunnel_encap *ipencap)
1800 {
1801 	int hlen;
1802 
1803 	memset(&t->encap, 0, sizeof(t->encap));
1804 
1805 	hlen = ip6_encap_hlen(ipencap);
1806 	if (hlen < 0)
1807 		return hlen;
1808 
1809 	t->encap.type = ipencap->type;
1810 	t->encap.sport = ipencap->sport;
1811 	t->encap.dport = ipencap->dport;
1812 	t->encap.flags = ipencap->flags;
1813 
1814 	t->encap_hlen = hlen;
1815 	t->hlen = t->encap_hlen + t->tun_hlen;
1816 
1817 	return 0;
1818 }
1819 EXPORT_SYMBOL_GPL(ip6_tnl_encap_setup);
1820 
1821 static const struct net_device_ops ip6_tnl_netdev_ops = {
1822 	.ndo_init	= ip6_tnl_dev_init,
1823 	.ndo_uninit	= ip6_tnl_dev_uninit,
1824 	.ndo_start_xmit = ip6_tnl_start_xmit,
1825 	.ndo_siocdevprivate = ip6_tnl_siocdevprivate,
1826 	.ndo_change_mtu = ip6_tnl_change_mtu,
1827 	.ndo_get_stats64 = dev_get_tstats64,
1828 	.ndo_get_iflink = ip6_tnl_get_iflink,
1829 };
1830 
1831 #define IPXIPX_FEATURES (NETIF_F_SG |		\
1832 			 NETIF_F_FRAGLIST |	\
1833 			 NETIF_F_HIGHDMA |	\
1834 			 NETIF_F_GSO_SOFTWARE |	\
1835 			 NETIF_F_HW_CSUM)
1836 
1837 /**
1838  * ip6_tnl_dev_setup - setup virtual tunnel device
1839  *   @dev: virtual device associated with tunnel
1840  *
1841  * Description:
1842  *   Initialize function pointers and device parameters
1843  **/
1844 
ip6_tnl_dev_setup(struct net_device * dev)1845 static void ip6_tnl_dev_setup(struct net_device *dev)
1846 {
1847 	dev->netdev_ops = &ip6_tnl_netdev_ops;
1848 	dev->header_ops = &ip_tunnel_header_ops;
1849 	dev->needs_free_netdev = true;
1850 	dev->priv_destructor = ip6_dev_free;
1851 
1852 	dev->type = ARPHRD_TUNNEL6;
1853 	dev->flags |= IFF_NOARP;
1854 	dev->addr_len = sizeof(struct in6_addr);
1855 	dev->lltx = true;
1856 	dev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS;
1857 	netif_keep_dst(dev);
1858 
1859 	dev->features		|= IPXIPX_FEATURES;
1860 	dev->hw_features	|= IPXIPX_FEATURES;
1861 
1862 	/* This perm addr will be used as interface identifier by IPv6 */
1863 	dev->addr_assign_type = NET_ADDR_RANDOM;
1864 	eth_random_addr(dev->perm_addr);
1865 }
1866 
1867 
1868 /**
1869  * ip6_tnl_dev_init_gen - general initializer for all tunnel devices
1870  *   @dev: virtual device associated with tunnel
1871  **/
1872 
1873 static inline int
ip6_tnl_dev_init_gen(struct net_device * dev)1874 ip6_tnl_dev_init_gen(struct net_device *dev)
1875 {
1876 	struct ip6_tnl *t = netdev_priv(dev);
1877 	int ret;
1878 	int t_hlen;
1879 
1880 	t->dev = dev;
1881 	t->net = dev_net(dev);
1882 
1883 	ret = dst_cache_init(&t->dst_cache, GFP_KERNEL);
1884 	if (ret)
1885 		return ret;
1886 
1887 	ret = gro_cells_init(&t->gro_cells, dev);
1888 	if (ret)
1889 		goto destroy_dst;
1890 
1891 	t->tun_hlen = 0;
1892 	t->hlen = t->encap_hlen + t->tun_hlen;
1893 	t_hlen = t->hlen + sizeof(struct ipv6hdr);
1894 
1895 	dev->type = ARPHRD_TUNNEL6;
1896 	dev->mtu = ETH_DATA_LEN - t_hlen;
1897 	if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1898 		dev->mtu -= 8;
1899 	dev->min_mtu = ETH_MIN_MTU;
1900 	dev->max_mtu = IP6_MAX_MTU - dev->hard_header_len - t_hlen;
1901 
1902 	netdev_hold(dev, &t->dev_tracker, GFP_KERNEL);
1903 	netdev_lockdep_set_classes(dev);
1904 	return 0;
1905 
1906 destroy_dst:
1907 	dst_cache_destroy(&t->dst_cache);
1908 
1909 	return ret;
1910 }
1911 
1912 /**
1913  * ip6_tnl_dev_init - initializer for all non fallback tunnel devices
1914  *   @dev: virtual device associated with tunnel
1915  **/
1916 
ip6_tnl_dev_init(struct net_device * dev)1917 static int ip6_tnl_dev_init(struct net_device *dev)
1918 {
1919 	struct ip6_tnl *t = netdev_priv(dev);
1920 	int err = ip6_tnl_dev_init_gen(dev);
1921 
1922 	if (err)
1923 		return err;
1924 	ip6_tnl_link_config(t);
1925 	if (t->parms.collect_md)
1926 		netif_keep_dst(dev);
1927 	return 0;
1928 }
1929 
1930 /**
1931  * ip6_fb_tnl_dev_init - initializer for fallback tunnel device
1932  *   @dev: fallback device
1933  *
1934  * Return: 0
1935  **/
1936 
ip6_fb_tnl_dev_init(struct net_device * dev)1937 static int __net_init ip6_fb_tnl_dev_init(struct net_device *dev)
1938 {
1939 	struct ip6_tnl *t = netdev_priv(dev);
1940 	struct net *net = dev_net(dev);
1941 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1942 
1943 	t->parms.proto = IPPROTO_IPV6;
1944 
1945 	rcu_assign_pointer(ip6n->tnls_wc[0], t);
1946 	return 0;
1947 }
1948 
ip6_tnl_validate(struct nlattr * tb[],struct nlattr * data[],struct netlink_ext_ack * extack)1949 static int ip6_tnl_validate(struct nlattr *tb[], struct nlattr *data[],
1950 			    struct netlink_ext_ack *extack)
1951 {
1952 	u8 proto;
1953 
1954 	if (!data || !data[IFLA_IPTUN_PROTO])
1955 		return 0;
1956 
1957 	proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1958 	if (proto != IPPROTO_IPV6 &&
1959 	    proto != IPPROTO_IPIP &&
1960 	    proto != 0)
1961 		return -EINVAL;
1962 
1963 	return 0;
1964 }
1965 
ip6_tnl_netlink_parms(struct nlattr * data[],struct __ip6_tnl_parm * parms)1966 static void ip6_tnl_netlink_parms(struct nlattr *data[],
1967 				  struct __ip6_tnl_parm *parms)
1968 {
1969 	memset(parms, 0, sizeof(*parms));
1970 
1971 	if (!data)
1972 		return;
1973 
1974 	if (data[IFLA_IPTUN_LINK])
1975 		parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
1976 
1977 	if (data[IFLA_IPTUN_LOCAL])
1978 		parms->laddr = nla_get_in6_addr(data[IFLA_IPTUN_LOCAL]);
1979 
1980 	if (data[IFLA_IPTUN_REMOTE])
1981 		parms->raddr = nla_get_in6_addr(data[IFLA_IPTUN_REMOTE]);
1982 
1983 	if (data[IFLA_IPTUN_TTL])
1984 		parms->hop_limit = nla_get_u8(data[IFLA_IPTUN_TTL]);
1985 
1986 	if (data[IFLA_IPTUN_ENCAP_LIMIT])
1987 		parms->encap_limit = nla_get_u8(data[IFLA_IPTUN_ENCAP_LIMIT]);
1988 
1989 	if (data[IFLA_IPTUN_FLOWINFO])
1990 		parms->flowinfo = nla_get_be32(data[IFLA_IPTUN_FLOWINFO]);
1991 
1992 	if (data[IFLA_IPTUN_FLAGS])
1993 		parms->flags = nla_get_u32(data[IFLA_IPTUN_FLAGS]);
1994 
1995 	if (data[IFLA_IPTUN_PROTO])
1996 		parms->proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1997 
1998 	if (data[IFLA_IPTUN_COLLECT_METADATA])
1999 		parms->collect_md = true;
2000 
2001 	if (data[IFLA_IPTUN_FWMARK])
2002 		parms->fwmark = nla_get_u32(data[IFLA_IPTUN_FWMARK]);
2003 }
2004 
ip6_tnl_newlink(struct net * src_net,struct net_device * dev,struct nlattr * tb[],struct nlattr * data[],struct netlink_ext_ack * extack)2005 static int ip6_tnl_newlink(struct net *src_net, struct net_device *dev,
2006 			   struct nlattr *tb[], struct nlattr *data[],
2007 			   struct netlink_ext_ack *extack)
2008 {
2009 	struct net *net = dev_net(dev);
2010 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2011 	struct ip_tunnel_encap ipencap;
2012 	struct ip6_tnl *nt, *t;
2013 	int err;
2014 
2015 	nt = netdev_priv(dev);
2016 
2017 	if (ip_tunnel_netlink_encap_parms(data, &ipencap)) {
2018 		err = ip6_tnl_encap_setup(nt, &ipencap);
2019 		if (err < 0)
2020 			return err;
2021 	}
2022 
2023 	ip6_tnl_netlink_parms(data, &nt->parms);
2024 
2025 	if (nt->parms.collect_md) {
2026 		if (rtnl_dereference(ip6n->collect_md_tun))
2027 			return -EEXIST;
2028 	} else {
2029 		t = ip6_tnl_locate(net, &nt->parms, 0);
2030 		if (!IS_ERR(t))
2031 			return -EEXIST;
2032 	}
2033 
2034 	err = ip6_tnl_create2(dev);
2035 	if (!err && tb[IFLA_MTU])
2036 		ip6_tnl_change_mtu(dev, nla_get_u32(tb[IFLA_MTU]));
2037 
2038 	return err;
2039 }
2040 
ip6_tnl_changelink(struct net_device * dev,struct nlattr * tb[],struct nlattr * data[],struct netlink_ext_ack * extack)2041 static int ip6_tnl_changelink(struct net_device *dev, struct nlattr *tb[],
2042 			      struct nlattr *data[],
2043 			      struct netlink_ext_ack *extack)
2044 {
2045 	struct ip6_tnl *t = netdev_priv(dev);
2046 	struct __ip6_tnl_parm p;
2047 	struct net *net = t->net;
2048 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2049 	struct ip_tunnel_encap ipencap;
2050 
2051 	if (dev == ip6n->fb_tnl_dev)
2052 		return -EINVAL;
2053 
2054 	if (ip_tunnel_netlink_encap_parms(data, &ipencap)) {
2055 		int err = ip6_tnl_encap_setup(t, &ipencap);
2056 
2057 		if (err < 0)
2058 			return err;
2059 	}
2060 	ip6_tnl_netlink_parms(data, &p);
2061 	if (p.collect_md)
2062 		return -EINVAL;
2063 
2064 	t = ip6_tnl_locate(net, &p, 0);
2065 	if (!IS_ERR(t)) {
2066 		if (t->dev != dev)
2067 			return -EEXIST;
2068 	} else
2069 		t = netdev_priv(dev);
2070 
2071 	ip6_tnl_update(t, &p);
2072 	return 0;
2073 }
2074 
ip6_tnl_dellink(struct net_device * dev,struct list_head * head)2075 static void ip6_tnl_dellink(struct net_device *dev, struct list_head *head)
2076 {
2077 	struct net *net = dev_net(dev);
2078 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2079 
2080 	if (dev != ip6n->fb_tnl_dev)
2081 		unregister_netdevice_queue(dev, head);
2082 }
2083 
ip6_tnl_get_size(const struct net_device * dev)2084 static size_t ip6_tnl_get_size(const struct net_device *dev)
2085 {
2086 	return
2087 		/* IFLA_IPTUN_LINK */
2088 		nla_total_size(4) +
2089 		/* IFLA_IPTUN_LOCAL */
2090 		nla_total_size(sizeof(struct in6_addr)) +
2091 		/* IFLA_IPTUN_REMOTE */
2092 		nla_total_size(sizeof(struct in6_addr)) +
2093 		/* IFLA_IPTUN_TTL */
2094 		nla_total_size(1) +
2095 		/* IFLA_IPTUN_ENCAP_LIMIT */
2096 		nla_total_size(1) +
2097 		/* IFLA_IPTUN_FLOWINFO */
2098 		nla_total_size(4) +
2099 		/* IFLA_IPTUN_FLAGS */
2100 		nla_total_size(4) +
2101 		/* IFLA_IPTUN_PROTO */
2102 		nla_total_size(1) +
2103 		/* IFLA_IPTUN_ENCAP_TYPE */
2104 		nla_total_size(2) +
2105 		/* IFLA_IPTUN_ENCAP_FLAGS */
2106 		nla_total_size(2) +
2107 		/* IFLA_IPTUN_ENCAP_SPORT */
2108 		nla_total_size(2) +
2109 		/* IFLA_IPTUN_ENCAP_DPORT */
2110 		nla_total_size(2) +
2111 		/* IFLA_IPTUN_COLLECT_METADATA */
2112 		nla_total_size(0) +
2113 		/* IFLA_IPTUN_FWMARK */
2114 		nla_total_size(4) +
2115 		0;
2116 }
2117 
ip6_tnl_fill_info(struct sk_buff * skb,const struct net_device * dev)2118 static int ip6_tnl_fill_info(struct sk_buff *skb, const struct net_device *dev)
2119 {
2120 	struct ip6_tnl *tunnel = netdev_priv(dev);
2121 	struct __ip6_tnl_parm *parm = &tunnel->parms;
2122 
2123 	if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
2124 	    nla_put_in6_addr(skb, IFLA_IPTUN_LOCAL, &parm->laddr) ||
2125 	    nla_put_in6_addr(skb, IFLA_IPTUN_REMOTE, &parm->raddr) ||
2126 	    nla_put_u8(skb, IFLA_IPTUN_TTL, parm->hop_limit) ||
2127 	    nla_put_u8(skb, IFLA_IPTUN_ENCAP_LIMIT, parm->encap_limit) ||
2128 	    nla_put_be32(skb, IFLA_IPTUN_FLOWINFO, parm->flowinfo) ||
2129 	    nla_put_u32(skb, IFLA_IPTUN_FLAGS, parm->flags) ||
2130 	    nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->proto) ||
2131 	    nla_put_u32(skb, IFLA_IPTUN_FWMARK, parm->fwmark))
2132 		goto nla_put_failure;
2133 
2134 	if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE, tunnel->encap.type) ||
2135 	    nla_put_be16(skb, IFLA_IPTUN_ENCAP_SPORT, tunnel->encap.sport) ||
2136 	    nla_put_be16(skb, IFLA_IPTUN_ENCAP_DPORT, tunnel->encap.dport) ||
2137 	    nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS, tunnel->encap.flags))
2138 		goto nla_put_failure;
2139 
2140 	if (parm->collect_md)
2141 		if (nla_put_flag(skb, IFLA_IPTUN_COLLECT_METADATA))
2142 			goto nla_put_failure;
2143 
2144 	return 0;
2145 
2146 nla_put_failure:
2147 	return -EMSGSIZE;
2148 }
2149 
ip6_tnl_get_link_net(const struct net_device * dev)2150 struct net *ip6_tnl_get_link_net(const struct net_device *dev)
2151 {
2152 	struct ip6_tnl *tunnel = netdev_priv(dev);
2153 
2154 	return READ_ONCE(tunnel->net);
2155 }
2156 EXPORT_SYMBOL(ip6_tnl_get_link_net);
2157 
2158 static const struct nla_policy ip6_tnl_policy[IFLA_IPTUN_MAX + 1] = {
2159 	[IFLA_IPTUN_LINK]		= { .type = NLA_U32 },
2160 	[IFLA_IPTUN_LOCAL]		= { .len = sizeof(struct in6_addr) },
2161 	[IFLA_IPTUN_REMOTE]		= { .len = sizeof(struct in6_addr) },
2162 	[IFLA_IPTUN_TTL]		= { .type = NLA_U8 },
2163 	[IFLA_IPTUN_ENCAP_LIMIT]	= { .type = NLA_U8 },
2164 	[IFLA_IPTUN_FLOWINFO]		= { .type = NLA_U32 },
2165 	[IFLA_IPTUN_FLAGS]		= { .type = NLA_U32 },
2166 	[IFLA_IPTUN_PROTO]		= { .type = NLA_U8 },
2167 	[IFLA_IPTUN_ENCAP_TYPE]		= { .type = NLA_U16 },
2168 	[IFLA_IPTUN_ENCAP_FLAGS]	= { .type = NLA_U16 },
2169 	[IFLA_IPTUN_ENCAP_SPORT]	= { .type = NLA_U16 },
2170 	[IFLA_IPTUN_ENCAP_DPORT]	= { .type = NLA_U16 },
2171 	[IFLA_IPTUN_COLLECT_METADATA]	= { .type = NLA_FLAG },
2172 	[IFLA_IPTUN_FWMARK]		= { .type = NLA_U32 },
2173 };
2174 
2175 static struct rtnl_link_ops ip6_link_ops __read_mostly = {
2176 	.kind		= "ip6tnl",
2177 	.maxtype	= IFLA_IPTUN_MAX,
2178 	.policy		= ip6_tnl_policy,
2179 	.priv_size	= sizeof(struct ip6_tnl),
2180 	.setup		= ip6_tnl_dev_setup,
2181 	.validate	= ip6_tnl_validate,
2182 	.newlink	= ip6_tnl_newlink,
2183 	.changelink	= ip6_tnl_changelink,
2184 	.dellink	= ip6_tnl_dellink,
2185 	.get_size	= ip6_tnl_get_size,
2186 	.fill_info	= ip6_tnl_fill_info,
2187 	.get_link_net	= ip6_tnl_get_link_net,
2188 };
2189 
2190 static struct xfrm6_tunnel ip4ip6_handler __read_mostly = {
2191 	.handler	= ip4ip6_rcv,
2192 	.err_handler	= ip4ip6_err,
2193 	.priority	=	1,
2194 };
2195 
2196 static struct xfrm6_tunnel ip6ip6_handler __read_mostly = {
2197 	.handler	= ip6ip6_rcv,
2198 	.err_handler	= ip6ip6_err,
2199 	.priority	=	1,
2200 };
2201 
2202 static struct xfrm6_tunnel mplsip6_handler __read_mostly = {
2203 	.handler	= mplsip6_rcv,
2204 	.err_handler	= mplsip6_err,
2205 	.priority	=	1,
2206 };
2207 
ip6_tnl_destroy_tunnels(struct net * net,struct list_head * list)2208 static void __net_exit ip6_tnl_destroy_tunnels(struct net *net, struct list_head *list)
2209 {
2210 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2211 	struct net_device *dev, *aux;
2212 	int h;
2213 	struct ip6_tnl *t;
2214 
2215 	for_each_netdev_safe(net, dev, aux)
2216 		if (dev->rtnl_link_ops == &ip6_link_ops)
2217 			unregister_netdevice_queue(dev, list);
2218 
2219 	for (h = 0; h < IP6_TUNNEL_HASH_SIZE; h++) {
2220 		t = rtnl_dereference(ip6n->tnls_r_l[h]);
2221 		while (t) {
2222 			/* If dev is in the same netns, it has already
2223 			 * been added to the list by the previous loop.
2224 			 */
2225 			if (!net_eq(dev_net(t->dev), net))
2226 				unregister_netdevice_queue(t->dev, list);
2227 			t = rtnl_dereference(t->next);
2228 		}
2229 	}
2230 
2231 	t = rtnl_dereference(ip6n->tnls_wc[0]);
2232 	while (t) {
2233 		/* If dev is in the same netns, it has already
2234 		 * been added to the list by the previous loop.
2235 		 */
2236 		if (!net_eq(dev_net(t->dev), net))
2237 			unregister_netdevice_queue(t->dev, list);
2238 		t = rtnl_dereference(t->next);
2239 	}
2240 }
2241 
ip6_tnl_init_net(struct net * net)2242 static int __net_init ip6_tnl_init_net(struct net *net)
2243 {
2244 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2245 	struct ip6_tnl *t = NULL;
2246 	int err;
2247 
2248 	ip6n->tnls[0] = ip6n->tnls_wc;
2249 	ip6n->tnls[1] = ip6n->tnls_r_l;
2250 
2251 	if (!net_has_fallback_tunnels(net))
2252 		return 0;
2253 	err = -ENOMEM;
2254 	ip6n->fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6tnl0",
2255 					NET_NAME_UNKNOWN, ip6_tnl_dev_setup);
2256 
2257 	if (!ip6n->fb_tnl_dev)
2258 		goto err_alloc_dev;
2259 	dev_net_set(ip6n->fb_tnl_dev, net);
2260 	ip6n->fb_tnl_dev->rtnl_link_ops = &ip6_link_ops;
2261 	/* FB netdevice is special: we have one, and only one per netns.
2262 	 * Allowing to move it to another netns is clearly unsafe.
2263 	 */
2264 	ip6n->fb_tnl_dev->netns_local = true;
2265 
2266 	err = ip6_fb_tnl_dev_init(ip6n->fb_tnl_dev);
2267 	if (err < 0)
2268 		goto err_register;
2269 
2270 	err = register_netdev(ip6n->fb_tnl_dev);
2271 	if (err < 0)
2272 		goto err_register;
2273 
2274 	t = netdev_priv(ip6n->fb_tnl_dev);
2275 
2276 	strcpy(t->parms.name, ip6n->fb_tnl_dev->name);
2277 	return 0;
2278 
2279 err_register:
2280 	free_netdev(ip6n->fb_tnl_dev);
2281 err_alloc_dev:
2282 	return err;
2283 }
2284 
ip6_tnl_exit_batch_rtnl(struct list_head * net_list,struct list_head * dev_to_kill)2285 static void __net_exit ip6_tnl_exit_batch_rtnl(struct list_head *net_list,
2286 					       struct list_head *dev_to_kill)
2287 {
2288 	struct net *net;
2289 
2290 	ASSERT_RTNL();
2291 	list_for_each_entry(net, net_list, exit_list)
2292 		ip6_tnl_destroy_tunnels(net, dev_to_kill);
2293 }
2294 
2295 static struct pernet_operations ip6_tnl_net_ops = {
2296 	.init = ip6_tnl_init_net,
2297 	.exit_batch_rtnl = ip6_tnl_exit_batch_rtnl,
2298 	.id   = &ip6_tnl_net_id,
2299 	.size = sizeof(struct ip6_tnl_net),
2300 };
2301 
2302 /**
2303  * ip6_tunnel_init - register protocol and reserve needed resources
2304  *
2305  * Return: 0 on success
2306  **/
2307 
ip6_tunnel_init(void)2308 static int __init ip6_tunnel_init(void)
2309 {
2310 	int  err;
2311 
2312 	if (!ipv6_mod_enabled())
2313 		return -EOPNOTSUPP;
2314 
2315 	err = register_pernet_device(&ip6_tnl_net_ops);
2316 	if (err < 0)
2317 		goto out_pernet;
2318 
2319 	err = xfrm6_tunnel_register(&ip4ip6_handler, AF_INET);
2320 	if (err < 0) {
2321 		pr_err("%s: can't register ip4ip6\n", __func__);
2322 		goto out_ip4ip6;
2323 	}
2324 
2325 	err = xfrm6_tunnel_register(&ip6ip6_handler, AF_INET6);
2326 	if (err < 0) {
2327 		pr_err("%s: can't register ip6ip6\n", __func__);
2328 		goto out_ip6ip6;
2329 	}
2330 
2331 	if (ip6_tnl_mpls_supported()) {
2332 		err = xfrm6_tunnel_register(&mplsip6_handler, AF_MPLS);
2333 		if (err < 0) {
2334 			pr_err("%s: can't register mplsip6\n", __func__);
2335 			goto out_mplsip6;
2336 		}
2337 	}
2338 
2339 	err = rtnl_link_register(&ip6_link_ops);
2340 	if (err < 0)
2341 		goto rtnl_link_failed;
2342 
2343 	return 0;
2344 
2345 rtnl_link_failed:
2346 	if (ip6_tnl_mpls_supported())
2347 		xfrm6_tunnel_deregister(&mplsip6_handler, AF_MPLS);
2348 out_mplsip6:
2349 	xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6);
2350 out_ip6ip6:
2351 	xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET);
2352 out_ip4ip6:
2353 	unregister_pernet_device(&ip6_tnl_net_ops);
2354 out_pernet:
2355 	return err;
2356 }
2357 
2358 /**
2359  * ip6_tunnel_cleanup - free resources and unregister protocol
2360  **/
2361 
ip6_tunnel_cleanup(void)2362 static void __exit ip6_tunnel_cleanup(void)
2363 {
2364 	rtnl_link_unregister(&ip6_link_ops);
2365 	if (xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET))
2366 		pr_info("%s: can't deregister ip4ip6\n", __func__);
2367 
2368 	if (xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6))
2369 		pr_info("%s: can't deregister ip6ip6\n", __func__);
2370 
2371 	if (ip6_tnl_mpls_supported() &&
2372 	    xfrm6_tunnel_deregister(&mplsip6_handler, AF_MPLS))
2373 		pr_info("%s: can't deregister mplsip6\n", __func__);
2374 	unregister_pernet_device(&ip6_tnl_net_ops);
2375 }
2376 
2377 module_init(ip6_tunnel_init);
2378 module_exit(ip6_tunnel_cleanup);
2379