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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 
57 MODULE_AUTHOR("Ville Nuorvala");
58 MODULE_DESCRIPTION("IPv6 tunneling device");
59 MODULE_LICENSE("GPL");
60 MODULE_ALIAS_RTNL_LINK("ip6tnl");
61 MODULE_ALIAS_NETDEV("ip6tnl0");
62 
63 #define IP6_TUNNEL_HASH_SIZE_SHIFT  5
64 #define IP6_TUNNEL_HASH_SIZE (1 << IP6_TUNNEL_HASH_SIZE_SHIFT)
65 
66 static bool log_ecn_error = true;
67 module_param(log_ecn_error, bool, 0644);
68 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
69 
HASH(const struct in6_addr * addr1,const struct in6_addr * addr2)70 static u32 HASH(const struct in6_addr *addr1, const struct in6_addr *addr2)
71 {
72 	u32 hash = ipv6_addr_hash(addr1) ^ ipv6_addr_hash(addr2);
73 
74 	return hash_32(hash, IP6_TUNNEL_HASH_SIZE_SHIFT);
75 }
76 
77 static int ip6_tnl_dev_init(struct net_device *dev);
78 static void ip6_tnl_dev_setup(struct net_device *dev);
79 static struct rtnl_link_ops ip6_link_ops __read_mostly;
80 
81 static unsigned int ip6_tnl_net_id __read_mostly;
82 struct ip6_tnl_net {
83 	/* the IPv6 tunnel fallback device */
84 	struct net_device *fb_tnl_dev;
85 	/* lists for storing tunnels in use */
86 	struct ip6_tnl __rcu *tnls_r_l[IP6_TUNNEL_HASH_SIZE];
87 	struct ip6_tnl __rcu *tnls_wc[1];
88 	struct ip6_tnl __rcu **tnls[2];
89 	struct ip6_tnl __rcu *collect_md_tun;
90 };
91 
ip6_tnl_mpls_supported(void)92 static inline int ip6_tnl_mpls_supported(void)
93 {
94 	return IS_ENABLED(CONFIG_MPLS);
95 }
96 
ip6_get_stats(struct net_device * dev)97 static struct net_device_stats *ip6_get_stats(struct net_device *dev)
98 {
99 	struct pcpu_sw_netstats tmp, sum = { 0 };
100 	int i;
101 
102 	for_each_possible_cpu(i) {
103 		unsigned int start;
104 		const struct pcpu_sw_netstats *tstats =
105 						   per_cpu_ptr(dev->tstats, i);
106 
107 		do {
108 			start = u64_stats_fetch_begin_irq(&tstats->syncp);
109 			tmp.rx_packets = tstats->rx_packets;
110 			tmp.rx_bytes = tstats->rx_bytes;
111 			tmp.tx_packets = tstats->tx_packets;
112 			tmp.tx_bytes =  tstats->tx_bytes;
113 		} while (u64_stats_fetch_retry_irq(&tstats->syncp, start));
114 
115 		sum.rx_packets += tmp.rx_packets;
116 		sum.rx_bytes   += tmp.rx_bytes;
117 		sum.tx_packets += tmp.tx_packets;
118 		sum.tx_bytes   += tmp.tx_bytes;
119 	}
120 	dev->stats.rx_packets = sum.rx_packets;
121 	dev->stats.rx_bytes   = sum.rx_bytes;
122 	dev->stats.tx_packets = sum.tx_packets;
123 	dev->stats.tx_bytes   = sum.tx_bytes;
124 	return &dev->stats;
125 }
126 
127 #define for_each_ip6_tunnel_rcu(start) \
128 	for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
129 
130 /**
131  * ip6_tnl_lookup - fetch tunnel matching the end-point addresses
132  *   @net: network namespace
133  *   @link: ifindex of underlying interface
134  *   @remote: the address of the tunnel exit-point
135  *   @local: the address of the tunnel entry-point
136  *
137  * Return:
138  *   tunnel matching given end-points if found,
139  *   else fallback tunnel if its device is up,
140  *   else %NULL
141  **/
142 
143 static struct ip6_tnl *
ip6_tnl_lookup(struct net * net,int link,const struct in6_addr * remote,const struct in6_addr * local)144 ip6_tnl_lookup(struct net *net, int link,
145 	       const struct in6_addr *remote, const struct in6_addr *local)
146 {
147 	unsigned int hash = HASH(remote, local);
148 	struct ip6_tnl *t, *cand = NULL;
149 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
150 	struct in6_addr any;
151 
152 	for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
153 		if (!ipv6_addr_equal(local, &t->parms.laddr) ||
154 		    !ipv6_addr_equal(remote, &t->parms.raddr) ||
155 		    !(t->dev->flags & IFF_UP))
156 			continue;
157 
158 		if (link == t->parms.link)
159 			return t;
160 		else
161 			cand = t;
162 	}
163 
164 	memset(&any, 0, sizeof(any));
165 	hash = HASH(&any, local);
166 	for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
167 		if (!ipv6_addr_equal(local, &t->parms.laddr) ||
168 		    !ipv6_addr_any(&t->parms.raddr) ||
169 		    !(t->dev->flags & IFF_UP))
170 			continue;
171 
172 		if (link == t->parms.link)
173 			return t;
174 		else if (!cand)
175 			cand = t;
176 	}
177 
178 	hash = HASH(remote, &any);
179 	for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
180 		if (!ipv6_addr_equal(remote, &t->parms.raddr) ||
181 		    !ipv6_addr_any(&t->parms.laddr) ||
182 		    !(t->dev->flags & IFF_UP))
183 			continue;
184 
185 		if (link == t->parms.link)
186 			return t;
187 		else if (!cand)
188 			cand = t;
189 	}
190 
191 	if (cand)
192 		return cand;
193 
194 	t = rcu_dereference(ip6n->collect_md_tun);
195 	if (t && t->dev->flags & IFF_UP)
196 		return t;
197 
198 	t = rcu_dereference(ip6n->tnls_wc[0]);
199 	if (t && (t->dev->flags & IFF_UP))
200 		return t;
201 
202 	return NULL;
203 }
204 
205 /**
206  * ip6_tnl_bucket - get head of list matching given tunnel parameters
207  *   @p: parameters containing tunnel end-points
208  *
209  * Description:
210  *   ip6_tnl_bucket() returns the head of the list matching the
211  *   &struct in6_addr entries laddr and raddr in @p.
212  *
213  * Return: head of IPv6 tunnel list
214  **/
215 
216 static struct ip6_tnl __rcu **
ip6_tnl_bucket(struct ip6_tnl_net * ip6n,const struct __ip6_tnl_parm * p)217 ip6_tnl_bucket(struct ip6_tnl_net *ip6n, const struct __ip6_tnl_parm *p)
218 {
219 	const struct in6_addr *remote = &p->raddr;
220 	const struct in6_addr *local = &p->laddr;
221 	unsigned int h = 0;
222 	int prio = 0;
223 
224 	if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) {
225 		prio = 1;
226 		h = HASH(remote, local);
227 	}
228 	return &ip6n->tnls[prio][h];
229 }
230 
231 /**
232  * ip6_tnl_link - add tunnel to hash table
233  *   @t: tunnel to be added
234  **/
235 
236 static void
ip6_tnl_link(struct ip6_tnl_net * ip6n,struct ip6_tnl * t)237 ip6_tnl_link(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
238 {
239 	struct ip6_tnl __rcu **tp = ip6_tnl_bucket(ip6n, &t->parms);
240 
241 	if (t->parms.collect_md)
242 		rcu_assign_pointer(ip6n->collect_md_tun, t);
243 	rcu_assign_pointer(t->next , rtnl_dereference(*tp));
244 	rcu_assign_pointer(*tp, t);
245 }
246 
247 /**
248  * ip6_tnl_unlink - remove tunnel from hash table
249  *   @t: tunnel to be removed
250  **/
251 
252 static void
ip6_tnl_unlink(struct ip6_tnl_net * ip6n,struct ip6_tnl * t)253 ip6_tnl_unlink(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
254 {
255 	struct ip6_tnl __rcu **tp;
256 	struct ip6_tnl *iter;
257 
258 	if (t->parms.collect_md)
259 		rcu_assign_pointer(ip6n->collect_md_tun, NULL);
260 
261 	for (tp = ip6_tnl_bucket(ip6n, &t->parms);
262 	     (iter = rtnl_dereference(*tp)) != NULL;
263 	     tp = &iter->next) {
264 		if (t == iter) {
265 			rcu_assign_pointer(*tp, t->next);
266 			break;
267 		}
268 	}
269 }
270 
ip6_dev_free(struct net_device * dev)271 static void ip6_dev_free(struct net_device *dev)
272 {
273 	struct ip6_tnl *t = netdev_priv(dev);
274 
275 	gro_cells_destroy(&t->gro_cells);
276 	dst_cache_destroy(&t->dst_cache);
277 	free_percpu(dev->tstats);
278 }
279 
ip6_tnl_create2(struct net_device * dev)280 static int ip6_tnl_create2(struct net_device *dev)
281 {
282 	struct ip6_tnl *t = netdev_priv(dev);
283 	struct net *net = dev_net(dev);
284 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
285 	int err;
286 
287 	t = netdev_priv(dev);
288 
289 	dev->rtnl_link_ops = &ip6_link_ops;
290 	err = register_netdevice(dev);
291 	if (err < 0)
292 		goto out;
293 
294 	strcpy(t->parms.name, dev->name);
295 
296 	ip6_tnl_link(ip6n, t);
297 	return 0;
298 
299 out:
300 	return err;
301 }
302 
303 /**
304  * ip6_tnl_create - create a new tunnel
305  *   @net: network namespace
306  *   @p: tunnel parameters
307  *
308  * Description:
309  *   Create tunnel matching given parameters.
310  *
311  * Return:
312  *   created tunnel or error pointer
313  **/
314 
ip6_tnl_create(struct net * net,struct __ip6_tnl_parm * p)315 static struct ip6_tnl *ip6_tnl_create(struct net *net, struct __ip6_tnl_parm *p)
316 {
317 	struct net_device *dev;
318 	struct ip6_tnl *t;
319 	char name[IFNAMSIZ];
320 	int err = -E2BIG;
321 
322 	if (p->name[0]) {
323 		if (!dev_valid_name(p->name))
324 			goto failed;
325 		strlcpy(name, p->name, IFNAMSIZ);
326 	} else {
327 		sprintf(name, "ip6tnl%%d");
328 	}
329 	err = -ENOMEM;
330 	dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
331 			   ip6_tnl_dev_setup);
332 	if (!dev)
333 		goto failed;
334 
335 	dev_net_set(dev, net);
336 
337 	t = netdev_priv(dev);
338 	t->parms = *p;
339 	t->net = dev_net(dev);
340 	err = ip6_tnl_create2(dev);
341 	if (err < 0)
342 		goto failed_free;
343 
344 	return t;
345 
346 failed_free:
347 	free_netdev(dev);
348 failed:
349 	return ERR_PTR(err);
350 }
351 
352 /**
353  * ip6_tnl_locate - find or create tunnel matching given parameters
354  *   @net: network namespace
355  *   @p: tunnel parameters
356  *   @create: != 0 if allowed to create new tunnel if no match found
357  *
358  * Description:
359  *   ip6_tnl_locate() first tries to locate an existing tunnel
360  *   based on @parms. If this is unsuccessful, but @create is set a new
361  *   tunnel device is created and registered for use.
362  *
363  * Return:
364  *   matching tunnel or error pointer
365  **/
366 
ip6_tnl_locate(struct net * net,struct __ip6_tnl_parm * p,int create)367 static struct ip6_tnl *ip6_tnl_locate(struct net *net,
368 		struct __ip6_tnl_parm *p, int create)
369 {
370 	const struct in6_addr *remote = &p->raddr;
371 	const struct in6_addr *local = &p->laddr;
372 	struct ip6_tnl __rcu **tp;
373 	struct ip6_tnl *t;
374 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
375 
376 	for (tp = ip6_tnl_bucket(ip6n, p);
377 	     (t = rtnl_dereference(*tp)) != NULL;
378 	     tp = &t->next) {
379 		if (ipv6_addr_equal(local, &t->parms.laddr) &&
380 		    ipv6_addr_equal(remote, &t->parms.raddr) &&
381 		    p->link == t->parms.link) {
382 			if (create)
383 				return ERR_PTR(-EEXIST);
384 
385 			return t;
386 		}
387 	}
388 	if (!create)
389 		return ERR_PTR(-ENODEV);
390 	return ip6_tnl_create(net, p);
391 }
392 
393 /**
394  * ip6_tnl_dev_uninit - tunnel device uninitializer
395  *   @dev: the device to be destroyed
396  *
397  * Description:
398  *   ip6_tnl_dev_uninit() removes tunnel from its list
399  **/
400 
401 static void
ip6_tnl_dev_uninit(struct net_device * dev)402 ip6_tnl_dev_uninit(struct net_device *dev)
403 {
404 	struct ip6_tnl *t = netdev_priv(dev);
405 	struct net *net = t->net;
406 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
407 
408 	if (dev == ip6n->fb_tnl_dev)
409 		RCU_INIT_POINTER(ip6n->tnls_wc[0], NULL);
410 	else
411 		ip6_tnl_unlink(ip6n, t);
412 	dst_cache_reset(&t->dst_cache);
413 	dev_put(dev);
414 }
415 
416 /**
417  * parse_tvl_tnl_enc_lim - handle encapsulation limit option
418  *   @skb: received socket buffer
419  *
420  * Return:
421  *   0 if none was found,
422  *   else index to encapsulation limit
423  **/
424 
ip6_tnl_parse_tlv_enc_lim(struct sk_buff * skb,__u8 * raw)425 __u16 ip6_tnl_parse_tlv_enc_lim(struct sk_buff *skb, __u8 *raw)
426 {
427 	const struct ipv6hdr *ipv6h = (const struct ipv6hdr *)raw;
428 	unsigned int nhoff = raw - skb->data;
429 	unsigned int off = nhoff + sizeof(*ipv6h);
430 	u8 nexthdr = ipv6h->nexthdr;
431 
432 	while (ipv6_ext_hdr(nexthdr) && nexthdr != NEXTHDR_NONE) {
433 		struct ipv6_opt_hdr *hdr;
434 		u16 optlen;
435 
436 		if (!pskb_may_pull(skb, off + sizeof(*hdr)))
437 			break;
438 
439 		hdr = (struct ipv6_opt_hdr *)(skb->data + off);
440 		if (nexthdr == NEXTHDR_FRAGMENT) {
441 			optlen = 8;
442 		} else if (nexthdr == NEXTHDR_AUTH) {
443 			optlen = ipv6_authlen(hdr);
444 		} else {
445 			optlen = ipv6_optlen(hdr);
446 		}
447 
448 		if (!pskb_may_pull(skb, off + optlen))
449 			break;
450 
451 		hdr = (struct ipv6_opt_hdr *)(skb->data + off);
452 		if (nexthdr == NEXTHDR_FRAGMENT) {
453 			struct frag_hdr *frag_hdr = (struct frag_hdr *)hdr;
454 
455 			if (frag_hdr->frag_off)
456 				break;
457 		}
458 		if (nexthdr == NEXTHDR_DEST) {
459 			u16 i = 2;
460 
461 			while (1) {
462 				struct ipv6_tlv_tnl_enc_lim *tel;
463 
464 				/* No more room for encapsulation limit */
465 				if (i + sizeof(*tel) > optlen)
466 					break;
467 
468 				tel = (struct ipv6_tlv_tnl_enc_lim *)(skb->data + off + i);
469 				/* return index of option if found and valid */
470 				if (tel->type == IPV6_TLV_TNL_ENCAP_LIMIT &&
471 				    tel->length == 1)
472 					return i + off - nhoff;
473 				/* else jump to next option */
474 				if (tel->type)
475 					i += tel->length + 2;
476 				else
477 					i++;
478 			}
479 		}
480 		nexthdr = hdr->nexthdr;
481 		off += optlen;
482 	}
483 	return 0;
484 }
485 EXPORT_SYMBOL(ip6_tnl_parse_tlv_enc_lim);
486 
487 /**
488  * ip6_tnl_err - tunnel error handler
489  *
490  * Description:
491  *   ip6_tnl_err() should handle errors in the tunnel according
492  *   to the specifications in RFC 2473.
493  **/
494 
495 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)496 ip6_tnl_err(struct sk_buff *skb, __u8 ipproto, struct inet6_skb_parm *opt,
497 	    u8 *type, u8 *code, int *msg, __u32 *info, int offset)
498 {
499 	const struct ipv6hdr *ipv6h = (const struct ipv6hdr *)skb->data;
500 	struct net *net = dev_net(skb->dev);
501 	u8 rel_type = ICMPV6_DEST_UNREACH;
502 	u8 rel_code = ICMPV6_ADDR_UNREACH;
503 	__u32 rel_info = 0;
504 	struct ip6_tnl *t;
505 	int err = -ENOENT;
506 	int rel_msg = 0;
507 	u8 tproto;
508 	__u16 len;
509 
510 	/* If the packet doesn't contain the original IPv6 header we are
511 	   in trouble since we might need the source address for further
512 	   processing of the error. */
513 
514 	rcu_read_lock();
515 	t = ip6_tnl_lookup(dev_net(skb->dev), skb->dev->ifindex, &ipv6h->daddr, &ipv6h->saddr);
516 	if (!t)
517 		goto out;
518 
519 	tproto = READ_ONCE(t->parms.proto);
520 	if (tproto != ipproto && tproto != 0)
521 		goto out;
522 
523 	err = 0;
524 
525 	switch (*type) {
526 	case ICMPV6_DEST_UNREACH:
527 		net_dbg_ratelimited("%s: Path to destination invalid or inactive!\n",
528 				    t->parms.name);
529 		rel_msg = 1;
530 		break;
531 	case ICMPV6_TIME_EXCEED:
532 		if ((*code) == ICMPV6_EXC_HOPLIMIT) {
533 			net_dbg_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
534 					    t->parms.name);
535 			rel_msg = 1;
536 		}
537 		break;
538 	case ICMPV6_PARAMPROB: {
539 		struct ipv6_tlv_tnl_enc_lim *tel;
540 		__u32 teli;
541 
542 		teli = 0;
543 		if ((*code) == ICMPV6_HDR_FIELD)
544 			teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
545 
546 		if (teli && teli == *info - 2) {
547 			tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
548 			if (tel->encap_limit == 0) {
549 				net_dbg_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
550 						    t->parms.name);
551 				rel_msg = 1;
552 			}
553 		} else {
554 			net_dbg_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
555 					    t->parms.name);
556 		}
557 		break;
558 	}
559 	case ICMPV6_PKT_TOOBIG: {
560 		__u32 mtu;
561 
562 		ip6_update_pmtu(skb, net, htonl(*info), 0, 0,
563 				sock_net_uid(net, NULL));
564 		mtu = *info - offset;
565 		if (mtu < IPV6_MIN_MTU)
566 			mtu = IPV6_MIN_MTU;
567 		len = sizeof(*ipv6h) + ntohs(ipv6h->payload_len);
568 		if (len > mtu) {
569 			rel_type = ICMPV6_PKT_TOOBIG;
570 			rel_code = 0;
571 			rel_info = mtu;
572 			rel_msg = 1;
573 		}
574 		break;
575 	}
576 	case NDISC_REDIRECT:
577 		ip6_redirect(skb, net, skb->dev->ifindex, 0,
578 			     sock_net_uid(net, NULL));
579 		break;
580 	}
581 
582 	*type = rel_type;
583 	*code = rel_code;
584 	*info = rel_info;
585 	*msg = rel_msg;
586 
587 out:
588 	rcu_read_unlock();
589 	return err;
590 }
591 
592 static int
ip4ip6_err(struct sk_buff * skb,struct inet6_skb_parm * opt,u8 type,u8 code,int offset,__be32 info)593 ip4ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
594 	   u8 type, u8 code, int offset, __be32 info)
595 {
596 	__u32 rel_info = ntohl(info);
597 	const struct iphdr *eiph;
598 	struct sk_buff *skb2;
599 	int err, rel_msg = 0;
600 	u8 rel_type = type;
601 	u8 rel_code = code;
602 	struct rtable *rt;
603 	struct flowi4 fl4;
604 
605 	err = ip6_tnl_err(skb, IPPROTO_IPIP, opt, &rel_type, &rel_code,
606 			  &rel_msg, &rel_info, offset);
607 	if (err < 0)
608 		return err;
609 
610 	if (rel_msg == 0)
611 		return 0;
612 
613 	switch (rel_type) {
614 	case ICMPV6_DEST_UNREACH:
615 		if (rel_code != ICMPV6_ADDR_UNREACH)
616 			return 0;
617 		rel_type = ICMP_DEST_UNREACH;
618 		rel_code = ICMP_HOST_UNREACH;
619 		break;
620 	case ICMPV6_PKT_TOOBIG:
621 		if (rel_code != 0)
622 			return 0;
623 		rel_type = ICMP_DEST_UNREACH;
624 		rel_code = ICMP_FRAG_NEEDED;
625 		break;
626 	default:
627 		return 0;
628 	}
629 
630 	if (!pskb_may_pull(skb, offset + sizeof(struct iphdr)))
631 		return 0;
632 
633 	skb2 = skb_clone(skb, GFP_ATOMIC);
634 	if (!skb2)
635 		return 0;
636 
637 	skb_dst_drop(skb2);
638 
639 	skb_pull(skb2, offset);
640 	skb_reset_network_header(skb2);
641 	eiph = ip_hdr(skb2);
642 
643 	/* Try to guess incoming interface */
644 	rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL, eiph->saddr,
645 				   0, 0, 0, IPPROTO_IPIP, RT_TOS(eiph->tos), 0);
646 	if (IS_ERR(rt))
647 		goto out;
648 
649 	skb2->dev = rt->dst.dev;
650 	ip_rt_put(rt);
651 
652 	/* route "incoming" packet */
653 	if (rt->rt_flags & RTCF_LOCAL) {
654 		rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL,
655 					   eiph->daddr, eiph->saddr, 0, 0,
656 					   IPPROTO_IPIP, RT_TOS(eiph->tos), 0);
657 		if (IS_ERR(rt) || rt->dst.dev->type != ARPHRD_TUNNEL6) {
658 			if (!IS_ERR(rt))
659 				ip_rt_put(rt);
660 			goto out;
661 		}
662 		skb_dst_set(skb2, &rt->dst);
663 	} else {
664 		if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos,
665 				   skb2->dev) ||
666 		    skb_dst(skb2)->dev->type != ARPHRD_TUNNEL6)
667 			goto out;
668 	}
669 
670 	/* change mtu on this route */
671 	if (rel_type == ICMP_DEST_UNREACH && rel_code == ICMP_FRAG_NEEDED) {
672 		if (rel_info > dst_mtu(skb_dst(skb2)))
673 			goto out;
674 
675 		skb_dst_update_pmtu_no_confirm(skb2, rel_info);
676 	}
677 
678 	icmp_send(skb2, rel_type, rel_code, htonl(rel_info));
679 
680 out:
681 	kfree_skb(skb2);
682 	return 0;
683 }
684 
685 static int
ip6ip6_err(struct sk_buff * skb,struct inet6_skb_parm * opt,u8 type,u8 code,int offset,__be32 info)686 ip6ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
687 	   u8 type, u8 code, int offset, __be32 info)
688 {
689 	__u32 rel_info = ntohl(info);
690 	int err, rel_msg = 0;
691 	u8 rel_type = type;
692 	u8 rel_code = code;
693 
694 	err = ip6_tnl_err(skb, IPPROTO_IPV6, opt, &rel_type, &rel_code,
695 			  &rel_msg, &rel_info, offset);
696 	if (err < 0)
697 		return err;
698 
699 	if (rel_msg && pskb_may_pull(skb, offset + sizeof(struct ipv6hdr))) {
700 		struct rt6_info *rt;
701 		struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
702 
703 		if (!skb2)
704 			return 0;
705 
706 		skb_dst_drop(skb2);
707 		skb_pull(skb2, offset);
708 		skb_reset_network_header(skb2);
709 
710 		/* Try to guess incoming interface */
711 		rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr,
712 				NULL, 0, skb2, 0);
713 
714 		if (rt && rt->dst.dev)
715 			skb2->dev = rt->dst.dev;
716 
717 		icmpv6_send(skb2, rel_type, rel_code, rel_info);
718 
719 		ip6_rt_put(rt);
720 
721 		kfree_skb(skb2);
722 	}
723 
724 	return 0;
725 }
726 
727 static int
mplsip6_err(struct sk_buff * skb,struct inet6_skb_parm * opt,u8 type,u8 code,int offset,__be32 info)728 mplsip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
729 	    u8 type, u8 code, int offset, __be32 info)
730 {
731 	__u32 rel_info = ntohl(info);
732 	int err, rel_msg = 0;
733 	u8 rel_type = type;
734 	u8 rel_code = code;
735 
736 	err = ip6_tnl_err(skb, IPPROTO_MPLS, opt, &rel_type, &rel_code,
737 			  &rel_msg, &rel_info, offset);
738 	return err;
739 }
740 
ip4ip6_dscp_ecn_decapsulate(const struct ip6_tnl * t,const struct ipv6hdr * ipv6h,struct sk_buff * skb)741 static int ip4ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
742 				       const struct ipv6hdr *ipv6h,
743 				       struct sk_buff *skb)
744 {
745 	__u8 dsfield = ipv6_get_dsfield(ipv6h) & ~INET_ECN_MASK;
746 
747 	if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
748 		ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, dsfield);
749 
750 	return IP6_ECN_decapsulate(ipv6h, skb);
751 }
752 
ip6ip6_dscp_ecn_decapsulate(const struct ip6_tnl * t,const struct ipv6hdr * ipv6h,struct sk_buff * skb)753 static int ip6ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
754 				       const struct ipv6hdr *ipv6h,
755 				       struct sk_buff *skb)
756 {
757 	if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
758 		ipv6_copy_dscp(ipv6_get_dsfield(ipv6h), ipv6_hdr(skb));
759 
760 	return IP6_ECN_decapsulate(ipv6h, skb);
761 }
762 
mplsip6_dscp_ecn_decapsulate(const struct ip6_tnl * t,const struct ipv6hdr * ipv6h,struct sk_buff * skb)763 static inline int mplsip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
764 					       const struct ipv6hdr *ipv6h,
765 					       struct sk_buff *skb)
766 {
767 	/* ECN is not supported in AF_MPLS */
768 	return 0;
769 }
770 
ip6_tnl_get_cap(struct ip6_tnl * t,const struct in6_addr * laddr,const struct in6_addr * raddr)771 __u32 ip6_tnl_get_cap(struct ip6_tnl *t,
772 			     const struct in6_addr *laddr,
773 			     const struct in6_addr *raddr)
774 {
775 	struct __ip6_tnl_parm *p = &t->parms;
776 	int ltype = ipv6_addr_type(laddr);
777 	int rtype = ipv6_addr_type(raddr);
778 	__u32 flags = 0;
779 
780 	if (ltype == IPV6_ADDR_ANY || rtype == IPV6_ADDR_ANY) {
781 		flags = IP6_TNL_F_CAP_PER_PACKET;
782 	} else if (ltype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
783 		   rtype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
784 		   !((ltype|rtype) & IPV6_ADDR_LOOPBACK) &&
785 		   (!((ltype|rtype) & IPV6_ADDR_LINKLOCAL) || p->link)) {
786 		if (ltype&IPV6_ADDR_UNICAST)
787 			flags |= IP6_TNL_F_CAP_XMIT;
788 		if (rtype&IPV6_ADDR_UNICAST)
789 			flags |= IP6_TNL_F_CAP_RCV;
790 	}
791 	return flags;
792 }
793 EXPORT_SYMBOL(ip6_tnl_get_cap);
794 
795 /* called with rcu_read_lock() */
ip6_tnl_rcv_ctl(struct ip6_tnl * t,const struct in6_addr * laddr,const struct in6_addr * raddr)796 int ip6_tnl_rcv_ctl(struct ip6_tnl *t,
797 				  const struct in6_addr *laddr,
798 				  const struct in6_addr *raddr)
799 {
800 	struct __ip6_tnl_parm *p = &t->parms;
801 	int ret = 0;
802 	struct net *net = t->net;
803 
804 	if ((p->flags & IP6_TNL_F_CAP_RCV) ||
805 	    ((p->flags & IP6_TNL_F_CAP_PER_PACKET) &&
806 	     (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_RCV))) {
807 		struct net_device *ldev = NULL;
808 
809 		if (p->link)
810 			ldev = dev_get_by_index_rcu(net, p->link);
811 
812 		if ((ipv6_addr_is_multicast(laddr) ||
813 		     likely(ipv6_chk_addr_and_flags(net, laddr, ldev, false,
814 						    0, IFA_F_TENTATIVE))) &&
815 		    ((p->flags & IP6_TNL_F_ALLOW_LOCAL_REMOTE) ||
816 		     likely(!ipv6_chk_addr_and_flags(net, raddr, ldev, true,
817 						     0, IFA_F_TENTATIVE))))
818 			ret = 1;
819 	}
820 	return ret;
821 }
822 EXPORT_SYMBOL_GPL(ip6_tnl_rcv_ctl);
823 
__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)824 static int __ip6_tnl_rcv(struct ip6_tnl *tunnel, struct sk_buff *skb,
825 			 const struct tnl_ptk_info *tpi,
826 			 struct metadata_dst *tun_dst,
827 			 int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
828 						const struct ipv6hdr *ipv6h,
829 						struct sk_buff *skb),
830 			 bool log_ecn_err)
831 {
832 	const struct ipv6hdr *ipv6h;
833 	int nh, err;
834 
835 	if ((!(tpi->flags & TUNNEL_CSUM) &&
836 	     (tunnel->parms.i_flags & TUNNEL_CSUM)) ||
837 	    ((tpi->flags & TUNNEL_CSUM) &&
838 	     !(tunnel->parms.i_flags & TUNNEL_CSUM))) {
839 		tunnel->dev->stats.rx_crc_errors++;
840 		tunnel->dev->stats.rx_errors++;
841 		goto drop;
842 	}
843 
844 	if (tunnel->parms.i_flags & TUNNEL_SEQ) {
845 		if (!(tpi->flags & TUNNEL_SEQ) ||
846 		    (tunnel->i_seqno &&
847 		     (s32)(ntohl(tpi->seq) - tunnel->i_seqno) < 0)) {
848 			tunnel->dev->stats.rx_fifo_errors++;
849 			tunnel->dev->stats.rx_errors++;
850 			goto drop;
851 		}
852 		tunnel->i_seqno = ntohl(tpi->seq) + 1;
853 	}
854 
855 	skb->protocol = tpi->proto;
856 
857 	/* Warning: All skb pointers will be invalidated! */
858 	if (tunnel->dev->type == ARPHRD_ETHER) {
859 		if (!pskb_may_pull(skb, ETH_HLEN)) {
860 			tunnel->dev->stats.rx_length_errors++;
861 			tunnel->dev->stats.rx_errors++;
862 			goto drop;
863 		}
864 
865 		skb->protocol = eth_type_trans(skb, tunnel->dev);
866 		skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
867 	} else {
868 		skb->dev = tunnel->dev;
869 	}
870 
871 	/* Save offset of outer header relative to skb->head,
872 	 * because we are going to reset the network header to the inner header
873 	 * and might change skb->head.
874 	 */
875 	nh = skb_network_header(skb) - skb->head;
876 
877 	skb_reset_network_header(skb);
878 
879 	if (!pskb_inet_may_pull(skb)) {
880 		DEV_STATS_INC(tunnel->dev, rx_length_errors);
881 		DEV_STATS_INC(tunnel->dev, rx_errors);
882 		goto drop;
883 	}
884 
885 	/* Get the outer header. */
886 	ipv6h = (struct ipv6hdr *)(skb->head + nh);
887 
888 	memset(skb->cb, 0, sizeof(struct inet6_skb_parm));
889 
890 	__skb_tunnel_rx(skb, tunnel->dev, tunnel->net);
891 
892 	err = dscp_ecn_decapsulate(tunnel, ipv6h, skb);
893 	if (unlikely(err)) {
894 		if (log_ecn_err)
895 			net_info_ratelimited("non-ECT from %pI6 with DS=%#x\n",
896 					     &ipv6h->saddr,
897 					     ipv6_get_dsfield(ipv6h));
898 		if (err > 1) {
899 			++tunnel->dev->stats.rx_frame_errors;
900 			++tunnel->dev->stats.rx_errors;
901 			goto drop;
902 		}
903 	}
904 
905 	dev_sw_netstats_rx_add(tunnel->dev, skb->len);
906 
907 	skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(tunnel->dev)));
908 
909 	if (tun_dst)
910 		skb_dst_set(skb, (struct dst_entry *)tun_dst);
911 
912 	gro_cells_receive(&tunnel->gro_cells, skb);
913 	return 0;
914 
915 drop:
916 	if (tun_dst)
917 		dst_release((struct dst_entry *)tun_dst);
918 	kfree_skb(skb);
919 	return 0;
920 }
921 
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)922 int ip6_tnl_rcv(struct ip6_tnl *t, struct sk_buff *skb,
923 		const struct tnl_ptk_info *tpi,
924 		struct metadata_dst *tun_dst,
925 		bool log_ecn_err)
926 {
927 	int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
928 				    const struct ipv6hdr *ipv6h,
929 				    struct sk_buff *skb);
930 
931 	dscp_ecn_decapsulate = ip6ip6_dscp_ecn_decapsulate;
932 	if (tpi->proto == htons(ETH_P_IP))
933 		dscp_ecn_decapsulate = ip4ip6_dscp_ecn_decapsulate;
934 
935 	return __ip6_tnl_rcv(t, skb, tpi, tun_dst, dscp_ecn_decapsulate,
936 			     log_ecn_err);
937 }
938 EXPORT_SYMBOL(ip6_tnl_rcv);
939 
940 static const struct tnl_ptk_info tpi_v6 = {
941 	/* no tunnel info required for ipxip6. */
942 	.proto = htons(ETH_P_IPV6),
943 };
944 
945 static const struct tnl_ptk_info tpi_v4 = {
946 	/* no tunnel info required for ipxip6. */
947 	.proto = htons(ETH_P_IP),
948 };
949 
950 static const struct tnl_ptk_info tpi_mpls = {
951 	/* no tunnel info required for mplsip6. */
952 	.proto = htons(ETH_P_MPLS_UC),
953 };
954 
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))955 static int ipxip6_rcv(struct sk_buff *skb, u8 ipproto,
956 		      const struct tnl_ptk_info *tpi,
957 		      int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
958 						  const struct ipv6hdr *ipv6h,
959 						  struct sk_buff *skb))
960 {
961 	struct ip6_tnl *t;
962 	const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
963 	struct metadata_dst *tun_dst = NULL;
964 	int ret = -1;
965 
966 	rcu_read_lock();
967 	t = ip6_tnl_lookup(dev_net(skb->dev), skb->dev->ifindex, &ipv6h->saddr, &ipv6h->daddr);
968 
969 	if (t) {
970 		u8 tproto = READ_ONCE(t->parms.proto);
971 
972 		if (tproto != ipproto && tproto != 0)
973 			goto drop;
974 		if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
975 			goto drop;
976 		ipv6h = ipv6_hdr(skb);
977 		if (!ip6_tnl_rcv_ctl(t, &ipv6h->daddr, &ipv6h->saddr))
978 			goto drop;
979 		if (iptunnel_pull_header(skb, 0, tpi->proto, false))
980 			goto drop;
981 		if (t->parms.collect_md) {
982 			tun_dst = ipv6_tun_rx_dst(skb, 0, 0, 0);
983 			if (!tun_dst)
984 				goto drop;
985 		}
986 		ret = __ip6_tnl_rcv(t, skb, tpi, tun_dst, dscp_ecn_decapsulate,
987 				    log_ecn_error);
988 	}
989 
990 	rcu_read_unlock();
991 
992 	return ret;
993 
994 drop:
995 	rcu_read_unlock();
996 	kfree_skb(skb);
997 	return 0;
998 }
999 
ip4ip6_rcv(struct sk_buff * skb)1000 static int ip4ip6_rcv(struct sk_buff *skb)
1001 {
1002 	return ipxip6_rcv(skb, IPPROTO_IPIP, &tpi_v4,
1003 			  ip4ip6_dscp_ecn_decapsulate);
1004 }
1005 
ip6ip6_rcv(struct sk_buff * skb)1006 static int ip6ip6_rcv(struct sk_buff *skb)
1007 {
1008 	return ipxip6_rcv(skb, IPPROTO_IPV6, &tpi_v6,
1009 			  ip6ip6_dscp_ecn_decapsulate);
1010 }
1011 
mplsip6_rcv(struct sk_buff * skb)1012 static int mplsip6_rcv(struct sk_buff *skb)
1013 {
1014 	return ipxip6_rcv(skb, IPPROTO_MPLS, &tpi_mpls,
1015 			  mplsip6_dscp_ecn_decapsulate);
1016 }
1017 
1018 struct ipv6_tel_txoption {
1019 	struct ipv6_txoptions ops;
1020 	__u8 dst_opt[8];
1021 };
1022 
init_tel_txopt(struct ipv6_tel_txoption * opt,__u8 encap_limit)1023 static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit)
1024 {
1025 	memset(opt, 0, sizeof(struct ipv6_tel_txoption));
1026 
1027 	opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT;
1028 	opt->dst_opt[3] = 1;
1029 	opt->dst_opt[4] = encap_limit;
1030 	opt->dst_opt[5] = IPV6_TLV_PADN;
1031 	opt->dst_opt[6] = 1;
1032 
1033 	opt->ops.dst1opt = (struct ipv6_opt_hdr *) opt->dst_opt;
1034 	opt->ops.opt_nflen = 8;
1035 }
1036 
1037 /**
1038  * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
1039  *   @t: the outgoing tunnel device
1040  *   @hdr: IPv6 header from the incoming packet
1041  *
1042  * Description:
1043  *   Avoid trivial tunneling loop by checking that tunnel exit-point
1044  *   doesn't match source of incoming packet.
1045  *
1046  * Return:
1047  *   1 if conflict,
1048  *   0 else
1049  **/
1050 
1051 static inline bool
ip6_tnl_addr_conflict(const struct ip6_tnl * t,const struct ipv6hdr * hdr)1052 ip6_tnl_addr_conflict(const struct ip6_tnl *t, const struct ipv6hdr *hdr)
1053 {
1054 	return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
1055 }
1056 
ip6_tnl_xmit_ctl(struct ip6_tnl * t,const struct in6_addr * laddr,const struct in6_addr * raddr)1057 int ip6_tnl_xmit_ctl(struct ip6_tnl *t,
1058 		     const struct in6_addr *laddr,
1059 		     const struct in6_addr *raddr)
1060 {
1061 	struct __ip6_tnl_parm *p = &t->parms;
1062 	int ret = 0;
1063 	struct net *net = t->net;
1064 
1065 	if (t->parms.collect_md)
1066 		return 1;
1067 
1068 	if ((p->flags & IP6_TNL_F_CAP_XMIT) ||
1069 	    ((p->flags & IP6_TNL_F_CAP_PER_PACKET) &&
1070 	     (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_XMIT))) {
1071 		struct net_device *ldev = NULL;
1072 
1073 		rcu_read_lock();
1074 		if (p->link)
1075 			ldev = dev_get_by_index_rcu(net, p->link);
1076 
1077 		if (unlikely(!ipv6_chk_addr_and_flags(net, laddr, ldev, false,
1078 						      0, IFA_F_TENTATIVE)))
1079 			pr_warn_ratelimited("%s xmit: Local address not yet configured!\n",
1080 					    p->name);
1081 		else if (!(p->flags & IP6_TNL_F_ALLOW_LOCAL_REMOTE) &&
1082 			 !ipv6_addr_is_multicast(raddr) &&
1083 			 unlikely(ipv6_chk_addr_and_flags(net, raddr, ldev,
1084 							  true, 0, IFA_F_TENTATIVE)))
1085 			pr_warn_ratelimited("%s xmit: Routing loop! Remote address found on this node!\n",
1086 					    p->name);
1087 		else
1088 			ret = 1;
1089 		rcu_read_unlock();
1090 	}
1091 	return ret;
1092 }
1093 EXPORT_SYMBOL_GPL(ip6_tnl_xmit_ctl);
1094 
1095 /**
1096  * ip6_tnl_xmit - encapsulate packet and send
1097  *   @skb: the outgoing socket buffer
1098  *   @dev: the outgoing tunnel device
1099  *   @dsfield: dscp code for outer header
1100  *   @fl6: flow of tunneled packet
1101  *   @encap_limit: encapsulation limit
1102  *   @pmtu: Path MTU is stored if packet is too big
1103  *   @proto: next header value
1104  *
1105  * Description:
1106  *   Build new header and do some sanity checks on the packet before sending
1107  *   it.
1108  *
1109  * Return:
1110  *   0 on success
1111  *   -1 fail
1112  *   %-EMSGSIZE message too big. return mtu in this case.
1113  **/
1114 
ip6_tnl_xmit(struct sk_buff * skb,struct net_device * dev,__u8 dsfield,struct flowi6 * fl6,int encap_limit,__u32 * pmtu,__u8 proto)1115 int ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev, __u8 dsfield,
1116 		 struct flowi6 *fl6, int encap_limit, __u32 *pmtu,
1117 		 __u8 proto)
1118 {
1119 	struct ip6_tnl *t = netdev_priv(dev);
1120 	struct net *net = t->net;
1121 	struct net_device_stats *stats = &t->dev->stats;
1122 	struct ipv6hdr *ipv6h;
1123 	struct ipv6_tel_txoption opt;
1124 	struct dst_entry *dst = NULL, *ndst = NULL;
1125 	struct net_device *tdev;
1126 	int mtu;
1127 	unsigned int eth_hlen = t->dev->type == ARPHRD_ETHER ? ETH_HLEN : 0;
1128 	unsigned int psh_hlen = sizeof(struct ipv6hdr) + t->encap_hlen;
1129 	unsigned int max_headroom = psh_hlen;
1130 	bool use_cache = false;
1131 	u8 hop_limit;
1132 	int err = -1;
1133 
1134 	if (t->parms.collect_md) {
1135 		hop_limit = skb_tunnel_info(skb)->key.ttl;
1136 		goto route_lookup;
1137 	} else {
1138 		hop_limit = t->parms.hop_limit;
1139 	}
1140 
1141 	/* NBMA tunnel */
1142 	if (ipv6_addr_any(&t->parms.raddr)) {
1143 		if (skb->protocol == htons(ETH_P_IPV6)) {
1144 			struct in6_addr *addr6;
1145 			struct neighbour *neigh;
1146 			int addr_type;
1147 
1148 			if (!skb_dst(skb))
1149 				goto tx_err_link_failure;
1150 
1151 			neigh = dst_neigh_lookup(skb_dst(skb),
1152 						 &ipv6_hdr(skb)->daddr);
1153 			if (!neigh)
1154 				goto tx_err_link_failure;
1155 
1156 			addr6 = (struct in6_addr *)&neigh->primary_key;
1157 			addr_type = ipv6_addr_type(addr6);
1158 
1159 			if (addr_type == IPV6_ADDR_ANY)
1160 				addr6 = &ipv6_hdr(skb)->daddr;
1161 
1162 			memcpy(&fl6->daddr, addr6, sizeof(fl6->daddr));
1163 			neigh_release(neigh);
1164 		}
1165 	} else if (t->parms.proto != 0 && !(t->parms.flags &
1166 					    (IP6_TNL_F_USE_ORIG_TCLASS |
1167 					     IP6_TNL_F_USE_ORIG_FWMARK))) {
1168 		/* enable the cache only if neither the outer protocol nor the
1169 		 * routing decision depends on the current inner header value
1170 		 */
1171 		use_cache = true;
1172 	}
1173 
1174 	if (use_cache)
1175 		dst = dst_cache_get(&t->dst_cache);
1176 
1177 	if (!ip6_tnl_xmit_ctl(t, &fl6->saddr, &fl6->daddr))
1178 		goto tx_err_link_failure;
1179 
1180 	if (!dst) {
1181 route_lookup:
1182 		/* add dsfield to flowlabel for route lookup */
1183 		fl6->flowlabel = ip6_make_flowinfo(dsfield, fl6->flowlabel);
1184 
1185 		dst = ip6_route_output(net, NULL, fl6);
1186 
1187 		if (dst->error)
1188 			goto tx_err_link_failure;
1189 		dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), NULL, 0);
1190 		if (IS_ERR(dst)) {
1191 			err = PTR_ERR(dst);
1192 			dst = NULL;
1193 			goto tx_err_link_failure;
1194 		}
1195 		if (t->parms.collect_md && ipv6_addr_any(&fl6->saddr) &&
1196 		    ipv6_dev_get_saddr(net, ip6_dst_idev(dst)->dev,
1197 				       &fl6->daddr, 0, &fl6->saddr))
1198 			goto tx_err_link_failure;
1199 		ndst = dst;
1200 	}
1201 
1202 	tdev = dst->dev;
1203 
1204 	if (tdev == dev) {
1205 		stats->collisions++;
1206 		net_warn_ratelimited("%s: Local routing loop detected!\n",
1207 				     t->parms.name);
1208 		goto tx_err_dst_release;
1209 	}
1210 	mtu = dst_mtu(dst) - eth_hlen - psh_hlen - t->tun_hlen;
1211 	if (encap_limit >= 0) {
1212 		max_headroom += 8;
1213 		mtu -= 8;
1214 	}
1215 	mtu = max(mtu, skb->protocol == htons(ETH_P_IPV6) ?
1216 		       IPV6_MIN_MTU : IPV4_MIN_MTU);
1217 
1218 	skb_dst_update_pmtu_no_confirm(skb, mtu);
1219 	if (skb->len - t->tun_hlen - eth_hlen > mtu && !skb_is_gso(skb)) {
1220 		*pmtu = mtu;
1221 		err = -EMSGSIZE;
1222 		goto tx_err_dst_release;
1223 	}
1224 
1225 	if (t->err_count > 0) {
1226 		if (time_before(jiffies,
1227 				t->err_time + IP6TUNNEL_ERR_TIMEO)) {
1228 			t->err_count--;
1229 
1230 			dst_link_failure(skb);
1231 		} else {
1232 			t->err_count = 0;
1233 		}
1234 	}
1235 
1236 	skb_scrub_packet(skb, !net_eq(t->net, dev_net(dev)));
1237 
1238 	/*
1239 	 * Okay, now see if we can stuff it in the buffer as-is.
1240 	 */
1241 	max_headroom += LL_RESERVED_SPACE(tdev);
1242 
1243 	if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
1244 	    (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
1245 		struct sk_buff *new_skb;
1246 
1247 		new_skb = skb_realloc_headroom(skb, max_headroom);
1248 		if (!new_skb)
1249 			goto tx_err_dst_release;
1250 
1251 		if (skb->sk)
1252 			skb_set_owner_w(new_skb, skb->sk);
1253 		consume_skb(skb);
1254 		skb = new_skb;
1255 	}
1256 
1257 	if (t->parms.collect_md) {
1258 		if (t->encap.type != TUNNEL_ENCAP_NONE)
1259 			goto tx_err_dst_release;
1260 	} else {
1261 		if (use_cache && ndst)
1262 			dst_cache_set_ip6(&t->dst_cache, ndst, &fl6->saddr);
1263 	}
1264 	skb_dst_set(skb, dst);
1265 
1266 	if (hop_limit == 0) {
1267 		if (skb->protocol == htons(ETH_P_IP))
1268 			hop_limit = ip_hdr(skb)->ttl;
1269 		else if (skb->protocol == htons(ETH_P_IPV6))
1270 			hop_limit = ipv6_hdr(skb)->hop_limit;
1271 		else
1272 			hop_limit = ip6_dst_hoplimit(dst);
1273 	}
1274 
1275 	/* Calculate max headroom for all the headers and adjust
1276 	 * needed_headroom if necessary.
1277 	 */
1278 	max_headroom = LL_RESERVED_SPACE(dst->dev) + sizeof(struct ipv6hdr)
1279 			+ dst->header_len + t->hlen;
1280 	if (max_headroom > READ_ONCE(dev->needed_headroom))
1281 		WRITE_ONCE(dev->needed_headroom, max_headroom);
1282 
1283 	err = ip6_tnl_encap(skb, t, &proto, fl6);
1284 	if (err)
1285 		return err;
1286 
1287 	if (encap_limit >= 0) {
1288 		init_tel_txopt(&opt, encap_limit);
1289 		ipv6_push_frag_opts(skb, &opt.ops, &proto);
1290 	}
1291 
1292 	skb_push(skb, sizeof(struct ipv6hdr));
1293 	skb_reset_network_header(skb);
1294 	ipv6h = ipv6_hdr(skb);
1295 	ip6_flow_hdr(ipv6h, dsfield,
1296 		     ip6_make_flowlabel(net, skb, fl6->flowlabel, true, fl6));
1297 	ipv6h->hop_limit = hop_limit;
1298 	ipv6h->nexthdr = proto;
1299 	ipv6h->saddr = fl6->saddr;
1300 	ipv6h->daddr = fl6->daddr;
1301 	ip6tunnel_xmit(NULL, skb, dev);
1302 	return 0;
1303 tx_err_link_failure:
1304 	stats->tx_carrier_errors++;
1305 	dst_link_failure(skb);
1306 tx_err_dst_release:
1307 	dst_release(dst);
1308 	return err;
1309 }
1310 EXPORT_SYMBOL(ip6_tnl_xmit);
1311 
1312 static inline int
ipxip6_tnl_xmit(struct sk_buff * skb,struct net_device * dev,u8 protocol)1313 ipxip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev,
1314 		u8 protocol)
1315 {
1316 	struct ip6_tnl *t = netdev_priv(dev);
1317 	struct ipv6hdr *ipv6h;
1318 	const struct iphdr  *iph;
1319 	int encap_limit = -1;
1320 	__u16 offset;
1321 	struct flowi6 fl6;
1322 	__u8 dsfield, orig_dsfield;
1323 	__u32 mtu;
1324 	u8 tproto;
1325 	int err;
1326 
1327 	tproto = READ_ONCE(t->parms.proto);
1328 	if (tproto != protocol && tproto != 0)
1329 		return -1;
1330 
1331 	if (t->parms.collect_md) {
1332 		struct ip_tunnel_info *tun_info;
1333 		const struct ip_tunnel_key *key;
1334 
1335 		tun_info = skb_tunnel_info(skb);
1336 		if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
1337 			     ip_tunnel_info_af(tun_info) != AF_INET6))
1338 			return -1;
1339 		key = &tun_info->key;
1340 		memset(&fl6, 0, sizeof(fl6));
1341 		fl6.flowi6_proto = protocol;
1342 		fl6.saddr = key->u.ipv6.src;
1343 		fl6.daddr = key->u.ipv6.dst;
1344 		fl6.flowlabel = key->label;
1345 		dsfield =  key->tos;
1346 		switch (protocol) {
1347 		case IPPROTO_IPIP:
1348 			iph = ip_hdr(skb);
1349 			orig_dsfield = ipv4_get_dsfield(iph);
1350 			break;
1351 		case IPPROTO_IPV6:
1352 			ipv6h = ipv6_hdr(skb);
1353 			orig_dsfield = ipv6_get_dsfield(ipv6h);
1354 			break;
1355 		default:
1356 			orig_dsfield = dsfield;
1357 			break;
1358 		}
1359 	} else {
1360 		if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1361 			encap_limit = t->parms.encap_limit;
1362 		if (protocol == IPPROTO_IPV6) {
1363 			offset = ip6_tnl_parse_tlv_enc_lim(skb,
1364 						skb_network_header(skb));
1365 			/* ip6_tnl_parse_tlv_enc_lim() might have
1366 			 * reallocated skb->head
1367 			 */
1368 			if (offset > 0) {
1369 				struct ipv6_tlv_tnl_enc_lim *tel;
1370 
1371 				tel = (void *)&skb_network_header(skb)[offset];
1372 				if (tel->encap_limit == 0) {
1373 					icmpv6_ndo_send(skb, ICMPV6_PARAMPROB,
1374 							ICMPV6_HDR_FIELD, offset + 2);
1375 					return -1;
1376 				}
1377 				encap_limit = tel->encap_limit - 1;
1378 			}
1379 		}
1380 
1381 		memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
1382 		fl6.flowi6_proto = protocol;
1383 
1384 		if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
1385 			fl6.flowi6_mark = skb->mark;
1386 		else
1387 			fl6.flowi6_mark = t->parms.fwmark;
1388 		switch (protocol) {
1389 		case IPPROTO_IPIP:
1390 			iph = ip_hdr(skb);
1391 			orig_dsfield = ipv4_get_dsfield(iph);
1392 			if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1393 				dsfield = orig_dsfield;
1394 			else
1395 				dsfield = ip6_tclass(t->parms.flowinfo);
1396 			break;
1397 		case IPPROTO_IPV6:
1398 			ipv6h = ipv6_hdr(skb);
1399 			orig_dsfield = ipv6_get_dsfield(ipv6h);
1400 			if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1401 				dsfield = orig_dsfield;
1402 			else
1403 				dsfield = ip6_tclass(t->parms.flowinfo);
1404 			if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
1405 				fl6.flowlabel |= ip6_flowlabel(ipv6h);
1406 			break;
1407 		default:
1408 			orig_dsfield = dsfield = ip6_tclass(t->parms.flowinfo);
1409 			break;
1410 		}
1411 	}
1412 
1413 	fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
1414 	dsfield = INET_ECN_encapsulate(dsfield, orig_dsfield);
1415 
1416 	if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP6))
1417 		return -1;
1418 
1419 	skb_set_inner_ipproto(skb, protocol);
1420 
1421 	err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
1422 			   protocol);
1423 	if (err != 0) {
1424 		/* XXX: send ICMP error even if DF is not set. */
1425 		if (err == -EMSGSIZE)
1426 			switch (protocol) {
1427 			case IPPROTO_IPIP:
1428 				icmp_ndo_send(skb, ICMP_DEST_UNREACH,
1429 					      ICMP_FRAG_NEEDED, htonl(mtu));
1430 				break;
1431 			case IPPROTO_IPV6:
1432 				icmpv6_ndo_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
1433 				break;
1434 			default:
1435 				break;
1436 			}
1437 		return -1;
1438 	}
1439 
1440 	return 0;
1441 }
1442 
1443 static netdev_tx_t
ip6_tnl_start_xmit(struct sk_buff * skb,struct net_device * dev)1444 ip6_tnl_start_xmit(struct sk_buff *skb, struct net_device *dev)
1445 {
1446 	struct ip6_tnl *t = netdev_priv(dev);
1447 	struct net_device_stats *stats = &t->dev->stats;
1448 	u8 ipproto;
1449 	int ret;
1450 
1451 	if (!pskb_inet_may_pull(skb))
1452 		goto tx_err;
1453 
1454 	switch (skb->protocol) {
1455 	case htons(ETH_P_IP):
1456 		ipproto = IPPROTO_IPIP;
1457 		break;
1458 	case htons(ETH_P_IPV6):
1459 		if (ip6_tnl_addr_conflict(t, ipv6_hdr(skb)))
1460 			goto tx_err;
1461 		ipproto = IPPROTO_IPV6;
1462 		break;
1463 	case htons(ETH_P_MPLS_UC):
1464 		ipproto = IPPROTO_MPLS;
1465 		break;
1466 	default:
1467 		goto tx_err;
1468 	}
1469 
1470 	ret = ipxip6_tnl_xmit(skb, dev, ipproto);
1471 	if (ret < 0)
1472 		goto tx_err;
1473 
1474 	return NETDEV_TX_OK;
1475 
1476 tx_err:
1477 	stats->tx_errors++;
1478 	stats->tx_dropped++;
1479 	kfree_skb(skb);
1480 	return NETDEV_TX_OK;
1481 }
1482 
ip6_tnl_link_config(struct ip6_tnl * t)1483 static void ip6_tnl_link_config(struct ip6_tnl *t)
1484 {
1485 	struct net_device *dev = t->dev;
1486 	struct net_device *tdev = NULL;
1487 	struct __ip6_tnl_parm *p = &t->parms;
1488 	struct flowi6 *fl6 = &t->fl.u.ip6;
1489 	int t_hlen;
1490 	int mtu;
1491 
1492 	memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
1493 	memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
1494 
1495 	/* Set up flowi template */
1496 	fl6->saddr = p->laddr;
1497 	fl6->daddr = p->raddr;
1498 	fl6->flowi6_oif = p->link;
1499 	fl6->flowlabel = 0;
1500 
1501 	if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
1502 		fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
1503 	if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
1504 		fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
1505 
1506 	p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
1507 	p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
1508 
1509 	if (p->flags&IP6_TNL_F_CAP_XMIT && p->flags&IP6_TNL_F_CAP_RCV)
1510 		dev->flags |= IFF_POINTOPOINT;
1511 	else
1512 		dev->flags &= ~IFF_POINTOPOINT;
1513 
1514 	t->tun_hlen = 0;
1515 	t->hlen = t->encap_hlen + t->tun_hlen;
1516 	t_hlen = t->hlen + sizeof(struct ipv6hdr);
1517 
1518 	if (p->flags & IP6_TNL_F_CAP_XMIT) {
1519 		int strict = (ipv6_addr_type(&p->raddr) &
1520 			      (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
1521 
1522 		struct rt6_info *rt = rt6_lookup(t->net,
1523 						 &p->raddr, &p->laddr,
1524 						 p->link, NULL, strict);
1525 		if (rt) {
1526 			tdev = rt->dst.dev;
1527 			ip6_rt_put(rt);
1528 		}
1529 
1530 		if (!tdev && p->link)
1531 			tdev = __dev_get_by_index(t->net, p->link);
1532 
1533 		if (tdev) {
1534 			dev->hard_header_len = tdev->hard_header_len + t_hlen;
1535 			mtu = min_t(unsigned int, tdev->mtu, IP6_MAX_MTU);
1536 
1537 			mtu = mtu - t_hlen;
1538 			if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1539 				mtu -= 8;
1540 
1541 			if (mtu < IPV6_MIN_MTU)
1542 				mtu = IPV6_MIN_MTU;
1543 			WRITE_ONCE(dev->mtu, mtu);
1544 		}
1545 	}
1546 }
1547 
1548 /**
1549  * ip6_tnl_change - update the tunnel parameters
1550  *   @t: tunnel to be changed
1551  *   @p: tunnel configuration parameters
1552  *
1553  * Description:
1554  *   ip6_tnl_change() updates the tunnel parameters
1555  **/
1556 
1557 static int
ip6_tnl_change(struct ip6_tnl * t,const struct __ip6_tnl_parm * p)1558 ip6_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p)
1559 {
1560 	t->parms.laddr = p->laddr;
1561 	t->parms.raddr = p->raddr;
1562 	t->parms.flags = p->flags;
1563 	t->parms.hop_limit = p->hop_limit;
1564 	t->parms.encap_limit = p->encap_limit;
1565 	t->parms.flowinfo = p->flowinfo;
1566 	t->parms.link = p->link;
1567 	t->parms.proto = p->proto;
1568 	t->parms.fwmark = p->fwmark;
1569 	dst_cache_reset(&t->dst_cache);
1570 	ip6_tnl_link_config(t);
1571 	return 0;
1572 }
1573 
ip6_tnl_update(struct ip6_tnl * t,struct __ip6_tnl_parm * p)1574 static int ip6_tnl_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
1575 {
1576 	struct net *net = t->net;
1577 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1578 	int err;
1579 
1580 	ip6_tnl_unlink(ip6n, t);
1581 	synchronize_net();
1582 	err = ip6_tnl_change(t, p);
1583 	ip6_tnl_link(ip6n, t);
1584 	netdev_state_change(t->dev);
1585 	return err;
1586 }
1587 
ip6_tnl0_update(struct ip6_tnl * t,struct __ip6_tnl_parm * p)1588 static int ip6_tnl0_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
1589 {
1590 	/* for default tnl0 device allow to change only the proto */
1591 	t->parms.proto = p->proto;
1592 	netdev_state_change(t->dev);
1593 	return 0;
1594 }
1595 
1596 static void
ip6_tnl_parm_from_user(struct __ip6_tnl_parm * p,const struct ip6_tnl_parm * u)1597 ip6_tnl_parm_from_user(struct __ip6_tnl_parm *p, const struct ip6_tnl_parm *u)
1598 {
1599 	p->laddr = u->laddr;
1600 	p->raddr = u->raddr;
1601 	p->flags = u->flags;
1602 	p->hop_limit = u->hop_limit;
1603 	p->encap_limit = u->encap_limit;
1604 	p->flowinfo = u->flowinfo;
1605 	p->link = u->link;
1606 	p->proto = u->proto;
1607 	memcpy(p->name, u->name, sizeof(u->name));
1608 }
1609 
1610 static void
ip6_tnl_parm_to_user(struct ip6_tnl_parm * u,const struct __ip6_tnl_parm * p)1611 ip6_tnl_parm_to_user(struct ip6_tnl_parm *u, const struct __ip6_tnl_parm *p)
1612 {
1613 	u->laddr = p->laddr;
1614 	u->raddr = p->raddr;
1615 	u->flags = p->flags;
1616 	u->hop_limit = p->hop_limit;
1617 	u->encap_limit = p->encap_limit;
1618 	u->flowinfo = p->flowinfo;
1619 	u->link = p->link;
1620 	u->proto = p->proto;
1621 	memcpy(u->name, p->name, sizeof(u->name));
1622 }
1623 
1624 /**
1625  * ip6_tnl_ioctl - configure ipv6 tunnels from userspace
1626  *   @dev: virtual device associated with tunnel
1627  *   @ifr: parameters passed from userspace
1628  *   @cmd: command to be performed
1629  *
1630  * Description:
1631  *   ip6_tnl_ioctl() is used for managing IPv6 tunnels
1632  *   from userspace.
1633  *
1634  *   The possible commands are the following:
1635  *     %SIOCGETTUNNEL: get tunnel parameters for device
1636  *     %SIOCADDTUNNEL: add tunnel matching given tunnel parameters
1637  *     %SIOCCHGTUNNEL: change tunnel parameters to those given
1638  *     %SIOCDELTUNNEL: delete tunnel
1639  *
1640  *   The fallback device "ip6tnl0", created during module
1641  *   initialization, can be used for creating other tunnel devices.
1642  *
1643  * Return:
1644  *   0 on success,
1645  *   %-EFAULT if unable to copy data to or from userspace,
1646  *   %-EPERM if current process hasn't %CAP_NET_ADMIN set
1647  *   %-EINVAL if passed tunnel parameters are invalid,
1648  *   %-EEXIST if changing a tunnel's parameters would cause a conflict
1649  *   %-ENODEV if attempting to change or delete a nonexisting device
1650  **/
1651 
1652 static int
ip6_tnl_ioctl(struct net_device * dev,struct ifreq * ifr,int cmd)1653 ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1654 {
1655 	int err = 0;
1656 	struct ip6_tnl_parm p;
1657 	struct __ip6_tnl_parm p1;
1658 	struct ip6_tnl *t = netdev_priv(dev);
1659 	struct net *net = t->net;
1660 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1661 
1662 	memset(&p1, 0, sizeof(p1));
1663 
1664 	switch (cmd) {
1665 	case SIOCGETTUNNEL:
1666 		if (dev == ip6n->fb_tnl_dev) {
1667 			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1668 				err = -EFAULT;
1669 				break;
1670 			}
1671 			ip6_tnl_parm_from_user(&p1, &p);
1672 			t = ip6_tnl_locate(net, &p1, 0);
1673 			if (IS_ERR(t))
1674 				t = netdev_priv(dev);
1675 		} else {
1676 			memset(&p, 0, sizeof(p));
1677 		}
1678 		ip6_tnl_parm_to_user(&p, &t->parms);
1679 		if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) {
1680 			err = -EFAULT;
1681 		}
1682 		break;
1683 	case SIOCADDTUNNEL:
1684 	case SIOCCHGTUNNEL:
1685 		err = -EPERM;
1686 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1687 			break;
1688 		err = -EFAULT;
1689 		if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1690 			break;
1691 		err = -EINVAL;
1692 		if (p.proto != IPPROTO_IPV6 && p.proto != IPPROTO_IPIP &&
1693 		    p.proto != 0)
1694 			break;
1695 		ip6_tnl_parm_from_user(&p1, &p);
1696 		t = ip6_tnl_locate(net, &p1, cmd == SIOCADDTUNNEL);
1697 		if (cmd == SIOCCHGTUNNEL) {
1698 			if (!IS_ERR(t)) {
1699 				if (t->dev != dev) {
1700 					err = -EEXIST;
1701 					break;
1702 				}
1703 			} else
1704 				t = netdev_priv(dev);
1705 			if (dev == ip6n->fb_tnl_dev)
1706 				err = ip6_tnl0_update(t, &p1);
1707 			else
1708 				err = ip6_tnl_update(t, &p1);
1709 		}
1710 		if (!IS_ERR(t)) {
1711 			err = 0;
1712 			ip6_tnl_parm_to_user(&p, &t->parms);
1713 			if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1714 				err = -EFAULT;
1715 
1716 		} else {
1717 			err = PTR_ERR(t);
1718 		}
1719 		break;
1720 	case SIOCDELTUNNEL:
1721 		err = -EPERM;
1722 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1723 			break;
1724 
1725 		if (dev == ip6n->fb_tnl_dev) {
1726 			err = -EFAULT;
1727 			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1728 				break;
1729 			err = -ENOENT;
1730 			ip6_tnl_parm_from_user(&p1, &p);
1731 			t = ip6_tnl_locate(net, &p1, 0);
1732 			if (IS_ERR(t))
1733 				break;
1734 			err = -EPERM;
1735 			if (t->dev == ip6n->fb_tnl_dev)
1736 				break;
1737 			dev = t->dev;
1738 		}
1739 		err = 0;
1740 		unregister_netdevice(dev);
1741 		break;
1742 	default:
1743 		err = -EINVAL;
1744 	}
1745 	return err;
1746 }
1747 
1748 /**
1749  * ip6_tnl_change_mtu - change mtu manually for tunnel device
1750  *   @dev: virtual device associated with tunnel
1751  *   @new_mtu: the new mtu
1752  *
1753  * Return:
1754  *   0 on success,
1755  *   %-EINVAL if mtu too small
1756  **/
1757 
ip6_tnl_change_mtu(struct net_device * dev,int new_mtu)1758 int ip6_tnl_change_mtu(struct net_device *dev, int new_mtu)
1759 {
1760 	struct ip6_tnl *tnl = netdev_priv(dev);
1761 
1762 	if (tnl->parms.proto == IPPROTO_IPV6) {
1763 		if (new_mtu < IPV6_MIN_MTU)
1764 			return -EINVAL;
1765 	} else {
1766 		if (new_mtu < ETH_MIN_MTU)
1767 			return -EINVAL;
1768 	}
1769 	if (tnl->parms.proto == IPPROTO_IPV6 || tnl->parms.proto == 0) {
1770 		if (new_mtu > IP6_MAX_MTU - dev->hard_header_len)
1771 			return -EINVAL;
1772 	} else {
1773 		if (new_mtu > IP_MAX_MTU - dev->hard_header_len)
1774 			return -EINVAL;
1775 	}
1776 	dev->mtu = new_mtu;
1777 	return 0;
1778 }
1779 EXPORT_SYMBOL(ip6_tnl_change_mtu);
1780 
ip6_tnl_get_iflink(const struct net_device * dev)1781 int ip6_tnl_get_iflink(const struct net_device *dev)
1782 {
1783 	struct ip6_tnl *t = netdev_priv(dev);
1784 
1785 	return t->parms.link;
1786 }
1787 EXPORT_SYMBOL(ip6_tnl_get_iflink);
1788 
ip6_tnl_encap_add_ops(const struct ip6_tnl_encap_ops * ops,unsigned int num)1789 int ip6_tnl_encap_add_ops(const struct ip6_tnl_encap_ops *ops,
1790 			  unsigned int num)
1791 {
1792 	if (num >= MAX_IPTUN_ENCAP_OPS)
1793 		return -ERANGE;
1794 
1795 	return !cmpxchg((const struct ip6_tnl_encap_ops **)
1796 			&ip6tun_encaps[num],
1797 			NULL, ops) ? 0 : -1;
1798 }
1799 EXPORT_SYMBOL(ip6_tnl_encap_add_ops);
1800 
ip6_tnl_encap_del_ops(const struct ip6_tnl_encap_ops * ops,unsigned int num)1801 int ip6_tnl_encap_del_ops(const struct ip6_tnl_encap_ops *ops,
1802 			  unsigned int num)
1803 {
1804 	int ret;
1805 
1806 	if (num >= MAX_IPTUN_ENCAP_OPS)
1807 		return -ERANGE;
1808 
1809 	ret = (cmpxchg((const struct ip6_tnl_encap_ops **)
1810 		       &ip6tun_encaps[num],
1811 		       ops, NULL) == ops) ? 0 : -1;
1812 
1813 	synchronize_net();
1814 
1815 	return ret;
1816 }
1817 EXPORT_SYMBOL(ip6_tnl_encap_del_ops);
1818 
ip6_tnl_encap_setup(struct ip6_tnl * t,struct ip_tunnel_encap * ipencap)1819 int ip6_tnl_encap_setup(struct ip6_tnl *t,
1820 			struct ip_tunnel_encap *ipencap)
1821 {
1822 	int hlen;
1823 
1824 	memset(&t->encap, 0, sizeof(t->encap));
1825 
1826 	hlen = ip6_encap_hlen(ipencap);
1827 	if (hlen < 0)
1828 		return hlen;
1829 
1830 	t->encap.type = ipencap->type;
1831 	t->encap.sport = ipencap->sport;
1832 	t->encap.dport = ipencap->dport;
1833 	t->encap.flags = ipencap->flags;
1834 
1835 	t->encap_hlen = hlen;
1836 	t->hlen = t->encap_hlen + t->tun_hlen;
1837 
1838 	return 0;
1839 }
1840 EXPORT_SYMBOL_GPL(ip6_tnl_encap_setup);
1841 
1842 static const struct net_device_ops ip6_tnl_netdev_ops = {
1843 	.ndo_init	= ip6_tnl_dev_init,
1844 	.ndo_uninit	= ip6_tnl_dev_uninit,
1845 	.ndo_start_xmit = ip6_tnl_start_xmit,
1846 	.ndo_do_ioctl	= ip6_tnl_ioctl,
1847 	.ndo_change_mtu = ip6_tnl_change_mtu,
1848 	.ndo_get_stats	= ip6_get_stats,
1849 	.ndo_get_iflink = ip6_tnl_get_iflink,
1850 };
1851 
1852 #define IPXIPX_FEATURES (NETIF_F_SG |		\
1853 			 NETIF_F_FRAGLIST |	\
1854 			 NETIF_F_HIGHDMA |	\
1855 			 NETIF_F_GSO_SOFTWARE |	\
1856 			 NETIF_F_HW_CSUM)
1857 
1858 /**
1859  * ip6_tnl_dev_setup - setup virtual tunnel device
1860  *   @dev: virtual device associated with tunnel
1861  *
1862  * Description:
1863  *   Initialize function pointers and device parameters
1864  **/
1865 
ip6_tnl_dev_setup(struct net_device * dev)1866 static void ip6_tnl_dev_setup(struct net_device *dev)
1867 {
1868 	dev->netdev_ops = &ip6_tnl_netdev_ops;
1869 	dev->header_ops = &ip_tunnel_header_ops;
1870 	dev->needs_free_netdev = true;
1871 	dev->priv_destructor = ip6_dev_free;
1872 
1873 	dev->type = ARPHRD_TUNNEL6;
1874 	dev->flags |= IFF_NOARP;
1875 	dev->addr_len = sizeof(struct in6_addr);
1876 	dev->features |= NETIF_F_LLTX;
1877 	netif_keep_dst(dev);
1878 
1879 	dev->features		|= IPXIPX_FEATURES;
1880 	dev->hw_features	|= IPXIPX_FEATURES;
1881 
1882 	/* This perm addr will be used as interface identifier by IPv6 */
1883 	dev->addr_assign_type = NET_ADDR_RANDOM;
1884 	eth_random_addr(dev->perm_addr);
1885 }
1886 
1887 
1888 /**
1889  * ip6_tnl_dev_init_gen - general initializer for all tunnel devices
1890  *   @dev: virtual device associated with tunnel
1891  **/
1892 
1893 static inline int
ip6_tnl_dev_init_gen(struct net_device * dev)1894 ip6_tnl_dev_init_gen(struct net_device *dev)
1895 {
1896 	struct ip6_tnl *t = netdev_priv(dev);
1897 	int ret;
1898 	int t_hlen;
1899 
1900 	t->dev = dev;
1901 	t->net = dev_net(dev);
1902 	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1903 	if (!dev->tstats)
1904 		return -ENOMEM;
1905 
1906 	ret = dst_cache_init(&t->dst_cache, GFP_KERNEL);
1907 	if (ret)
1908 		goto free_stats;
1909 
1910 	ret = gro_cells_init(&t->gro_cells, dev);
1911 	if (ret)
1912 		goto destroy_dst;
1913 
1914 	t->tun_hlen = 0;
1915 	t->hlen = t->encap_hlen + t->tun_hlen;
1916 	t_hlen = t->hlen + sizeof(struct ipv6hdr);
1917 
1918 	dev->type = ARPHRD_TUNNEL6;
1919 	dev->hard_header_len = LL_MAX_HEADER + t_hlen;
1920 	dev->mtu = ETH_DATA_LEN - t_hlen;
1921 	if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1922 		dev->mtu -= 8;
1923 	dev->min_mtu = ETH_MIN_MTU;
1924 	dev->max_mtu = IP6_MAX_MTU - dev->hard_header_len;
1925 
1926 	dev_hold(dev);
1927 	return 0;
1928 
1929 destroy_dst:
1930 	dst_cache_destroy(&t->dst_cache);
1931 free_stats:
1932 	free_percpu(dev->tstats);
1933 	dev->tstats = NULL;
1934 
1935 	return ret;
1936 }
1937 
1938 /**
1939  * ip6_tnl_dev_init - initializer for all non fallback tunnel devices
1940  *   @dev: virtual device associated with tunnel
1941  **/
1942 
ip6_tnl_dev_init(struct net_device * dev)1943 static int ip6_tnl_dev_init(struct net_device *dev)
1944 {
1945 	struct ip6_tnl *t = netdev_priv(dev);
1946 	int err = ip6_tnl_dev_init_gen(dev);
1947 
1948 	if (err)
1949 		return err;
1950 	ip6_tnl_link_config(t);
1951 	if (t->parms.collect_md)
1952 		netif_keep_dst(dev);
1953 	return 0;
1954 }
1955 
1956 /**
1957  * ip6_fb_tnl_dev_init - initializer for fallback tunnel device
1958  *   @dev: fallback device
1959  *
1960  * Return: 0
1961  **/
1962 
ip6_fb_tnl_dev_init(struct net_device * dev)1963 static int __net_init ip6_fb_tnl_dev_init(struct net_device *dev)
1964 {
1965 	struct ip6_tnl *t = netdev_priv(dev);
1966 	struct net *net = dev_net(dev);
1967 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1968 
1969 	t->parms.proto = IPPROTO_IPV6;
1970 
1971 	rcu_assign_pointer(ip6n->tnls_wc[0], t);
1972 	return 0;
1973 }
1974 
ip6_tnl_validate(struct nlattr * tb[],struct nlattr * data[],struct netlink_ext_ack * extack)1975 static int ip6_tnl_validate(struct nlattr *tb[], struct nlattr *data[],
1976 			    struct netlink_ext_ack *extack)
1977 {
1978 	u8 proto;
1979 
1980 	if (!data || !data[IFLA_IPTUN_PROTO])
1981 		return 0;
1982 
1983 	proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1984 	if (proto != IPPROTO_IPV6 &&
1985 	    proto != IPPROTO_IPIP &&
1986 	    proto != 0)
1987 		return -EINVAL;
1988 
1989 	return 0;
1990 }
1991 
ip6_tnl_netlink_parms(struct nlattr * data[],struct __ip6_tnl_parm * parms)1992 static void ip6_tnl_netlink_parms(struct nlattr *data[],
1993 				  struct __ip6_tnl_parm *parms)
1994 {
1995 	memset(parms, 0, sizeof(*parms));
1996 
1997 	if (!data)
1998 		return;
1999 
2000 	if (data[IFLA_IPTUN_LINK])
2001 		parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
2002 
2003 	if (data[IFLA_IPTUN_LOCAL])
2004 		parms->laddr = nla_get_in6_addr(data[IFLA_IPTUN_LOCAL]);
2005 
2006 	if (data[IFLA_IPTUN_REMOTE])
2007 		parms->raddr = nla_get_in6_addr(data[IFLA_IPTUN_REMOTE]);
2008 
2009 	if (data[IFLA_IPTUN_TTL])
2010 		parms->hop_limit = nla_get_u8(data[IFLA_IPTUN_TTL]);
2011 
2012 	if (data[IFLA_IPTUN_ENCAP_LIMIT])
2013 		parms->encap_limit = nla_get_u8(data[IFLA_IPTUN_ENCAP_LIMIT]);
2014 
2015 	if (data[IFLA_IPTUN_FLOWINFO])
2016 		parms->flowinfo = nla_get_be32(data[IFLA_IPTUN_FLOWINFO]);
2017 
2018 	if (data[IFLA_IPTUN_FLAGS])
2019 		parms->flags = nla_get_u32(data[IFLA_IPTUN_FLAGS]);
2020 
2021 	if (data[IFLA_IPTUN_PROTO])
2022 		parms->proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
2023 
2024 	if (data[IFLA_IPTUN_COLLECT_METADATA])
2025 		parms->collect_md = true;
2026 
2027 	if (data[IFLA_IPTUN_FWMARK])
2028 		parms->fwmark = nla_get_u32(data[IFLA_IPTUN_FWMARK]);
2029 }
2030 
ip6_tnl_netlink_encap_parms(struct nlattr * data[],struct ip_tunnel_encap * ipencap)2031 static bool ip6_tnl_netlink_encap_parms(struct nlattr *data[],
2032 					struct ip_tunnel_encap *ipencap)
2033 {
2034 	bool ret = false;
2035 
2036 	memset(ipencap, 0, sizeof(*ipencap));
2037 
2038 	if (!data)
2039 		return ret;
2040 
2041 	if (data[IFLA_IPTUN_ENCAP_TYPE]) {
2042 		ret = true;
2043 		ipencap->type = nla_get_u16(data[IFLA_IPTUN_ENCAP_TYPE]);
2044 	}
2045 
2046 	if (data[IFLA_IPTUN_ENCAP_FLAGS]) {
2047 		ret = true;
2048 		ipencap->flags = nla_get_u16(data[IFLA_IPTUN_ENCAP_FLAGS]);
2049 	}
2050 
2051 	if (data[IFLA_IPTUN_ENCAP_SPORT]) {
2052 		ret = true;
2053 		ipencap->sport = nla_get_be16(data[IFLA_IPTUN_ENCAP_SPORT]);
2054 	}
2055 
2056 	if (data[IFLA_IPTUN_ENCAP_DPORT]) {
2057 		ret = true;
2058 		ipencap->dport = nla_get_be16(data[IFLA_IPTUN_ENCAP_DPORT]);
2059 	}
2060 
2061 	return ret;
2062 }
2063 
ip6_tnl_newlink(struct net * src_net,struct net_device * dev,struct nlattr * tb[],struct nlattr * data[],struct netlink_ext_ack * extack)2064 static int ip6_tnl_newlink(struct net *src_net, struct net_device *dev,
2065 			   struct nlattr *tb[], struct nlattr *data[],
2066 			   struct netlink_ext_ack *extack)
2067 {
2068 	struct net *net = dev_net(dev);
2069 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2070 	struct ip_tunnel_encap ipencap;
2071 	struct ip6_tnl *nt, *t;
2072 	int err;
2073 
2074 	nt = netdev_priv(dev);
2075 
2076 	if (ip6_tnl_netlink_encap_parms(data, &ipencap)) {
2077 		err = ip6_tnl_encap_setup(nt, &ipencap);
2078 		if (err < 0)
2079 			return err;
2080 	}
2081 
2082 	ip6_tnl_netlink_parms(data, &nt->parms);
2083 
2084 	if (nt->parms.collect_md) {
2085 		if (rtnl_dereference(ip6n->collect_md_tun))
2086 			return -EEXIST;
2087 	} else {
2088 		t = ip6_tnl_locate(net, &nt->parms, 0);
2089 		if (!IS_ERR(t))
2090 			return -EEXIST;
2091 	}
2092 
2093 	err = ip6_tnl_create2(dev);
2094 	if (!err && tb[IFLA_MTU])
2095 		ip6_tnl_change_mtu(dev, nla_get_u32(tb[IFLA_MTU]));
2096 
2097 	return err;
2098 }
2099 
ip6_tnl_changelink(struct net_device * dev,struct nlattr * tb[],struct nlattr * data[],struct netlink_ext_ack * extack)2100 static int ip6_tnl_changelink(struct net_device *dev, struct nlattr *tb[],
2101 			      struct nlattr *data[],
2102 			      struct netlink_ext_ack *extack)
2103 {
2104 	struct ip6_tnl *t = netdev_priv(dev);
2105 	struct __ip6_tnl_parm p;
2106 	struct net *net = t->net;
2107 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2108 	struct ip_tunnel_encap ipencap;
2109 
2110 	if (dev == ip6n->fb_tnl_dev)
2111 		return -EINVAL;
2112 
2113 	if (ip6_tnl_netlink_encap_parms(data, &ipencap)) {
2114 		int err = ip6_tnl_encap_setup(t, &ipencap);
2115 
2116 		if (err < 0)
2117 			return err;
2118 	}
2119 	ip6_tnl_netlink_parms(data, &p);
2120 	if (p.collect_md)
2121 		return -EINVAL;
2122 
2123 	t = ip6_tnl_locate(net, &p, 0);
2124 	if (!IS_ERR(t)) {
2125 		if (t->dev != dev)
2126 			return -EEXIST;
2127 	} else
2128 		t = netdev_priv(dev);
2129 
2130 	return ip6_tnl_update(t, &p);
2131 }
2132 
ip6_tnl_dellink(struct net_device * dev,struct list_head * head)2133 static void ip6_tnl_dellink(struct net_device *dev, struct list_head *head)
2134 {
2135 	struct net *net = dev_net(dev);
2136 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2137 
2138 	if (dev != ip6n->fb_tnl_dev)
2139 		unregister_netdevice_queue(dev, head);
2140 }
2141 
ip6_tnl_get_size(const struct net_device * dev)2142 static size_t ip6_tnl_get_size(const struct net_device *dev)
2143 {
2144 	return
2145 		/* IFLA_IPTUN_LINK */
2146 		nla_total_size(4) +
2147 		/* IFLA_IPTUN_LOCAL */
2148 		nla_total_size(sizeof(struct in6_addr)) +
2149 		/* IFLA_IPTUN_REMOTE */
2150 		nla_total_size(sizeof(struct in6_addr)) +
2151 		/* IFLA_IPTUN_TTL */
2152 		nla_total_size(1) +
2153 		/* IFLA_IPTUN_ENCAP_LIMIT */
2154 		nla_total_size(1) +
2155 		/* IFLA_IPTUN_FLOWINFO */
2156 		nla_total_size(4) +
2157 		/* IFLA_IPTUN_FLAGS */
2158 		nla_total_size(4) +
2159 		/* IFLA_IPTUN_PROTO */
2160 		nla_total_size(1) +
2161 		/* IFLA_IPTUN_ENCAP_TYPE */
2162 		nla_total_size(2) +
2163 		/* IFLA_IPTUN_ENCAP_FLAGS */
2164 		nla_total_size(2) +
2165 		/* IFLA_IPTUN_ENCAP_SPORT */
2166 		nla_total_size(2) +
2167 		/* IFLA_IPTUN_ENCAP_DPORT */
2168 		nla_total_size(2) +
2169 		/* IFLA_IPTUN_COLLECT_METADATA */
2170 		nla_total_size(0) +
2171 		/* IFLA_IPTUN_FWMARK */
2172 		nla_total_size(4) +
2173 		0;
2174 }
2175 
ip6_tnl_fill_info(struct sk_buff * skb,const struct net_device * dev)2176 static int ip6_tnl_fill_info(struct sk_buff *skb, const struct net_device *dev)
2177 {
2178 	struct ip6_tnl *tunnel = netdev_priv(dev);
2179 	struct __ip6_tnl_parm *parm = &tunnel->parms;
2180 
2181 	if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
2182 	    nla_put_in6_addr(skb, IFLA_IPTUN_LOCAL, &parm->laddr) ||
2183 	    nla_put_in6_addr(skb, IFLA_IPTUN_REMOTE, &parm->raddr) ||
2184 	    nla_put_u8(skb, IFLA_IPTUN_TTL, parm->hop_limit) ||
2185 	    nla_put_u8(skb, IFLA_IPTUN_ENCAP_LIMIT, parm->encap_limit) ||
2186 	    nla_put_be32(skb, IFLA_IPTUN_FLOWINFO, parm->flowinfo) ||
2187 	    nla_put_u32(skb, IFLA_IPTUN_FLAGS, parm->flags) ||
2188 	    nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->proto) ||
2189 	    nla_put_u32(skb, IFLA_IPTUN_FWMARK, parm->fwmark))
2190 		goto nla_put_failure;
2191 
2192 	if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE, tunnel->encap.type) ||
2193 	    nla_put_be16(skb, IFLA_IPTUN_ENCAP_SPORT, tunnel->encap.sport) ||
2194 	    nla_put_be16(skb, IFLA_IPTUN_ENCAP_DPORT, tunnel->encap.dport) ||
2195 	    nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS, tunnel->encap.flags))
2196 		goto nla_put_failure;
2197 
2198 	if (parm->collect_md)
2199 		if (nla_put_flag(skb, IFLA_IPTUN_COLLECT_METADATA))
2200 			goto nla_put_failure;
2201 
2202 	return 0;
2203 
2204 nla_put_failure:
2205 	return -EMSGSIZE;
2206 }
2207 
ip6_tnl_get_link_net(const struct net_device * dev)2208 struct net *ip6_tnl_get_link_net(const struct net_device *dev)
2209 {
2210 	struct ip6_tnl *tunnel = netdev_priv(dev);
2211 
2212 	return tunnel->net;
2213 }
2214 EXPORT_SYMBOL(ip6_tnl_get_link_net);
2215 
2216 static const struct nla_policy ip6_tnl_policy[IFLA_IPTUN_MAX + 1] = {
2217 	[IFLA_IPTUN_LINK]		= { .type = NLA_U32 },
2218 	[IFLA_IPTUN_LOCAL]		= { .len = sizeof(struct in6_addr) },
2219 	[IFLA_IPTUN_REMOTE]		= { .len = sizeof(struct in6_addr) },
2220 	[IFLA_IPTUN_TTL]		= { .type = NLA_U8 },
2221 	[IFLA_IPTUN_ENCAP_LIMIT]	= { .type = NLA_U8 },
2222 	[IFLA_IPTUN_FLOWINFO]		= { .type = NLA_U32 },
2223 	[IFLA_IPTUN_FLAGS]		= { .type = NLA_U32 },
2224 	[IFLA_IPTUN_PROTO]		= { .type = NLA_U8 },
2225 	[IFLA_IPTUN_ENCAP_TYPE]		= { .type = NLA_U16 },
2226 	[IFLA_IPTUN_ENCAP_FLAGS]	= { .type = NLA_U16 },
2227 	[IFLA_IPTUN_ENCAP_SPORT]	= { .type = NLA_U16 },
2228 	[IFLA_IPTUN_ENCAP_DPORT]	= { .type = NLA_U16 },
2229 	[IFLA_IPTUN_COLLECT_METADATA]	= { .type = NLA_FLAG },
2230 	[IFLA_IPTUN_FWMARK]		= { .type = NLA_U32 },
2231 };
2232 
2233 static struct rtnl_link_ops ip6_link_ops __read_mostly = {
2234 	.kind		= "ip6tnl",
2235 	.maxtype	= IFLA_IPTUN_MAX,
2236 	.policy		= ip6_tnl_policy,
2237 	.priv_size	= sizeof(struct ip6_tnl),
2238 	.setup		= ip6_tnl_dev_setup,
2239 	.validate	= ip6_tnl_validate,
2240 	.newlink	= ip6_tnl_newlink,
2241 	.changelink	= ip6_tnl_changelink,
2242 	.dellink	= ip6_tnl_dellink,
2243 	.get_size	= ip6_tnl_get_size,
2244 	.fill_info	= ip6_tnl_fill_info,
2245 	.get_link_net	= ip6_tnl_get_link_net,
2246 };
2247 
2248 static struct xfrm6_tunnel ip4ip6_handler __read_mostly = {
2249 	.handler	= ip4ip6_rcv,
2250 	.err_handler	= ip4ip6_err,
2251 	.priority	=	1,
2252 };
2253 
2254 static struct xfrm6_tunnel ip6ip6_handler __read_mostly = {
2255 	.handler	= ip6ip6_rcv,
2256 	.err_handler	= ip6ip6_err,
2257 	.priority	=	1,
2258 };
2259 
2260 static struct xfrm6_tunnel mplsip6_handler __read_mostly = {
2261 	.handler	= mplsip6_rcv,
2262 	.err_handler	= mplsip6_err,
2263 	.priority	=	1,
2264 };
2265 
ip6_tnl_destroy_tunnels(struct net * net,struct list_head * list)2266 static void __net_exit ip6_tnl_destroy_tunnels(struct net *net, struct list_head *list)
2267 {
2268 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2269 	struct net_device *dev, *aux;
2270 	int h;
2271 	struct ip6_tnl *t;
2272 
2273 	for_each_netdev_safe(net, dev, aux)
2274 		if (dev->rtnl_link_ops == &ip6_link_ops)
2275 			unregister_netdevice_queue(dev, list);
2276 
2277 	for (h = 0; h < IP6_TUNNEL_HASH_SIZE; h++) {
2278 		t = rtnl_dereference(ip6n->tnls_r_l[h]);
2279 		while (t) {
2280 			/* If dev is in the same netns, it has already
2281 			 * been added to the list by the previous loop.
2282 			 */
2283 			if (!net_eq(dev_net(t->dev), net))
2284 				unregister_netdevice_queue(t->dev, list);
2285 			t = rtnl_dereference(t->next);
2286 		}
2287 	}
2288 
2289 	t = rtnl_dereference(ip6n->tnls_wc[0]);
2290 	while (t) {
2291 		/* If dev is in the same netns, it has already
2292 		 * been added to the list by the previous loop.
2293 		 */
2294 		if (!net_eq(dev_net(t->dev), net))
2295 			unregister_netdevice_queue(t->dev, list);
2296 		t = rtnl_dereference(t->next);
2297 	}
2298 }
2299 
ip6_tnl_init_net(struct net * net)2300 static int __net_init ip6_tnl_init_net(struct net *net)
2301 {
2302 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2303 	struct ip6_tnl *t = NULL;
2304 	int err;
2305 
2306 	ip6n->tnls[0] = ip6n->tnls_wc;
2307 	ip6n->tnls[1] = ip6n->tnls_r_l;
2308 
2309 	if (!net_has_fallback_tunnels(net))
2310 		return 0;
2311 	err = -ENOMEM;
2312 	ip6n->fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6tnl0",
2313 					NET_NAME_UNKNOWN, ip6_tnl_dev_setup);
2314 
2315 	if (!ip6n->fb_tnl_dev)
2316 		goto err_alloc_dev;
2317 	dev_net_set(ip6n->fb_tnl_dev, net);
2318 	ip6n->fb_tnl_dev->rtnl_link_ops = &ip6_link_ops;
2319 	/* FB netdevice is special: we have one, and only one per netns.
2320 	 * Allowing to move it to another netns is clearly unsafe.
2321 	 */
2322 	ip6n->fb_tnl_dev->features |= NETIF_F_NETNS_LOCAL;
2323 
2324 	err = ip6_fb_tnl_dev_init(ip6n->fb_tnl_dev);
2325 	if (err < 0)
2326 		goto err_register;
2327 
2328 	err = register_netdev(ip6n->fb_tnl_dev);
2329 	if (err < 0)
2330 		goto err_register;
2331 
2332 	t = netdev_priv(ip6n->fb_tnl_dev);
2333 
2334 	strcpy(t->parms.name, ip6n->fb_tnl_dev->name);
2335 	return 0;
2336 
2337 err_register:
2338 	free_netdev(ip6n->fb_tnl_dev);
2339 err_alloc_dev:
2340 	return err;
2341 }
2342 
ip6_tnl_exit_batch_net(struct list_head * net_list)2343 static void __net_exit ip6_tnl_exit_batch_net(struct list_head *net_list)
2344 {
2345 	struct net *net;
2346 	LIST_HEAD(list);
2347 
2348 	rtnl_lock();
2349 	list_for_each_entry(net, net_list, exit_list)
2350 		ip6_tnl_destroy_tunnels(net, &list);
2351 	unregister_netdevice_many(&list);
2352 	rtnl_unlock();
2353 }
2354 
2355 static struct pernet_operations ip6_tnl_net_ops = {
2356 	.init = ip6_tnl_init_net,
2357 	.exit_batch = ip6_tnl_exit_batch_net,
2358 	.id   = &ip6_tnl_net_id,
2359 	.size = sizeof(struct ip6_tnl_net),
2360 };
2361 
2362 /**
2363  * ip6_tunnel_init - register protocol and reserve needed resources
2364  *
2365  * Return: 0 on success
2366  **/
2367 
ip6_tunnel_init(void)2368 static int __init ip6_tunnel_init(void)
2369 {
2370 	int  err;
2371 
2372 	if (!ipv6_mod_enabled())
2373 		return -EOPNOTSUPP;
2374 
2375 	err = register_pernet_device(&ip6_tnl_net_ops);
2376 	if (err < 0)
2377 		goto out_pernet;
2378 
2379 	err = xfrm6_tunnel_register(&ip4ip6_handler, AF_INET);
2380 	if (err < 0) {
2381 		pr_err("%s: can't register ip4ip6\n", __func__);
2382 		goto out_ip4ip6;
2383 	}
2384 
2385 	err = xfrm6_tunnel_register(&ip6ip6_handler, AF_INET6);
2386 	if (err < 0) {
2387 		pr_err("%s: can't register ip6ip6\n", __func__);
2388 		goto out_ip6ip6;
2389 	}
2390 
2391 	if (ip6_tnl_mpls_supported()) {
2392 		err = xfrm6_tunnel_register(&mplsip6_handler, AF_MPLS);
2393 		if (err < 0) {
2394 			pr_err("%s: can't register mplsip6\n", __func__);
2395 			goto out_mplsip6;
2396 		}
2397 	}
2398 
2399 	err = rtnl_link_register(&ip6_link_ops);
2400 	if (err < 0)
2401 		goto rtnl_link_failed;
2402 
2403 	return 0;
2404 
2405 rtnl_link_failed:
2406 	if (ip6_tnl_mpls_supported())
2407 		xfrm6_tunnel_deregister(&mplsip6_handler, AF_MPLS);
2408 out_mplsip6:
2409 	xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6);
2410 out_ip6ip6:
2411 	xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET);
2412 out_ip4ip6:
2413 	unregister_pernet_device(&ip6_tnl_net_ops);
2414 out_pernet:
2415 	return err;
2416 }
2417 
2418 /**
2419  * ip6_tunnel_cleanup - free resources and unregister protocol
2420  **/
2421 
ip6_tunnel_cleanup(void)2422 static void __exit ip6_tunnel_cleanup(void)
2423 {
2424 	rtnl_link_unregister(&ip6_link_ops);
2425 	if (xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET))
2426 		pr_info("%s: can't deregister ip4ip6\n", __func__);
2427 
2428 	if (xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6))
2429 		pr_info("%s: can't deregister ip6ip6\n", __func__);
2430 
2431 	if (ip6_tnl_mpls_supported() &&
2432 	    xfrm6_tunnel_deregister(&mplsip6_handler, AF_MPLS))
2433 		pr_info("%s: can't deregister mplsip6\n", __func__);
2434 	unregister_pernet_device(&ip6_tnl_net_ops);
2435 }
2436 
2437 module_init(ip6_tunnel_init);
2438 module_exit(ip6_tunnel_cleanup);
2439