xref: /kernel/linux/linux-6.6/net/ipv6/ip6_tunnel.c (revision 62306a36)
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
57MODULE_AUTHOR("Ville Nuorvala");
58MODULE_DESCRIPTION("IPv6 tunneling device");
59MODULE_LICENSE("GPL");
60MODULE_ALIAS_RTNL_LINK("ip6tnl");
61MODULE_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
66static bool log_ecn_error = true;
67module_param(log_ecn_error, bool, 0644);
68MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
69
70static 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
77static int ip6_tnl_dev_init(struct net_device *dev);
78static void ip6_tnl_dev_setup(struct net_device *dev);
79static struct rtnl_link_ops ip6_link_ops __read_mostly;
80
81static unsigned int ip6_tnl_net_id __read_mostly;
82struct 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
92static inline int ip6_tnl_mpls_supported(void)
93{
94	return IS_ENABLED(CONFIG_MPLS);
95}
96
97#define for_each_ip6_tunnel_rcu(start) \
98	for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
99
100/**
101 * ip6_tnl_lookup - fetch tunnel matching the end-point addresses
102 *   @net: network namespace
103 *   @link: ifindex of underlying interface
104 *   @remote: the address of the tunnel exit-point
105 *   @local: the address of the tunnel entry-point
106 *
107 * Return:
108 *   tunnel matching given end-points if found,
109 *   else fallback tunnel if its device is up,
110 *   else %NULL
111 **/
112
113static struct ip6_tnl *
114ip6_tnl_lookup(struct net *net, int link,
115	       const struct in6_addr *remote, const struct in6_addr *local)
116{
117	unsigned int hash = HASH(remote, local);
118	struct ip6_tnl *t, *cand = NULL;
119	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
120	struct in6_addr any;
121
122	for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
123		if (!ipv6_addr_equal(local, &t->parms.laddr) ||
124		    !ipv6_addr_equal(remote, &t->parms.raddr) ||
125		    !(t->dev->flags & IFF_UP))
126			continue;
127
128		if (link == t->parms.link)
129			return t;
130		else
131			cand = t;
132	}
133
134	memset(&any, 0, sizeof(any));
135	hash = HASH(&any, local);
136	for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
137		if (!ipv6_addr_equal(local, &t->parms.laddr) ||
138		    !ipv6_addr_any(&t->parms.raddr) ||
139		    !(t->dev->flags & IFF_UP))
140			continue;
141
142		if (link == t->parms.link)
143			return t;
144		else if (!cand)
145			cand = t;
146	}
147
148	hash = HASH(remote, &any);
149	for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
150		if (!ipv6_addr_equal(remote, &t->parms.raddr) ||
151		    !ipv6_addr_any(&t->parms.laddr) ||
152		    !(t->dev->flags & IFF_UP))
153			continue;
154
155		if (link == t->parms.link)
156			return t;
157		else if (!cand)
158			cand = t;
159	}
160
161	if (cand)
162		return cand;
163
164	t = rcu_dereference(ip6n->collect_md_tun);
165	if (t && t->dev->flags & IFF_UP)
166		return t;
167
168	t = rcu_dereference(ip6n->tnls_wc[0]);
169	if (t && (t->dev->flags & IFF_UP))
170		return t;
171
172	return NULL;
173}
174
175/**
176 * ip6_tnl_bucket - get head of list matching given tunnel parameters
177 *   @ip6n: the private data for ip6_vti in the netns
178 *   @p: parameters containing tunnel end-points
179 *
180 * Description:
181 *   ip6_tnl_bucket() returns the head of the list matching the
182 *   &struct in6_addr entries laddr and raddr in @p.
183 *
184 * Return: head of IPv6 tunnel list
185 **/
186
187static struct ip6_tnl __rcu **
188ip6_tnl_bucket(struct ip6_tnl_net *ip6n, const struct __ip6_tnl_parm *p)
189{
190	const struct in6_addr *remote = &p->raddr;
191	const struct in6_addr *local = &p->laddr;
192	unsigned int h = 0;
193	int prio = 0;
194
195	if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) {
196		prio = 1;
197		h = HASH(remote, local);
198	}
199	return &ip6n->tnls[prio][h];
200}
201
202/**
203 * ip6_tnl_link - add tunnel to hash table
204 *   @ip6n: the private data for ip6_vti in the netns
205 *   @t: tunnel to be added
206 **/
207
208static void
209ip6_tnl_link(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
210{
211	struct ip6_tnl __rcu **tp = ip6_tnl_bucket(ip6n, &t->parms);
212
213	if (t->parms.collect_md)
214		rcu_assign_pointer(ip6n->collect_md_tun, t);
215	rcu_assign_pointer(t->next , rtnl_dereference(*tp));
216	rcu_assign_pointer(*tp, t);
217}
218
219/**
220 * ip6_tnl_unlink - remove tunnel from hash table
221 *   @ip6n: the private data for ip6_vti in the netns
222 *   @t: tunnel to be removed
223 **/
224
225static void
226ip6_tnl_unlink(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
227{
228	struct ip6_tnl __rcu **tp;
229	struct ip6_tnl *iter;
230
231	if (t->parms.collect_md)
232		rcu_assign_pointer(ip6n->collect_md_tun, NULL);
233
234	for (tp = ip6_tnl_bucket(ip6n, &t->parms);
235	     (iter = rtnl_dereference(*tp)) != NULL;
236	     tp = &iter->next) {
237		if (t == iter) {
238			rcu_assign_pointer(*tp, t->next);
239			break;
240		}
241	}
242}
243
244static void ip6_dev_free(struct net_device *dev)
245{
246	struct ip6_tnl *t = netdev_priv(dev);
247
248	gro_cells_destroy(&t->gro_cells);
249	dst_cache_destroy(&t->dst_cache);
250	free_percpu(dev->tstats);
251}
252
253static 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
270out:
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
286static 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
317failed_free:
318	free_netdev(dev);
319failed:
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
338static 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
372static void
373ip6_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
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}
457EXPORT_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 */
462static int
463ip6_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
554out:
555	rcu_read_unlock();
556	return err;
557}
558
559static int
560ip4ip6_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, RT_TOS(eiph->tos), 0);
613	if (IS_ERR(rt))
614		goto out;
615
616	skb2->dev = rt->dst.dev;
617	ip_rt_put(rt);
618
619	/* route "incoming" packet */
620	if (rt->rt_flags & RTCF_LOCAL) {
621		rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL,
622					   eiph->daddr, eiph->saddr, 0, 0,
623					   IPPROTO_IPIP, RT_TOS(eiph->tos), 0);
624		if (IS_ERR(rt) || rt->dst.dev->type != ARPHRD_TUNNEL6) {
625			if (!IS_ERR(rt))
626				ip_rt_put(rt);
627			goto out;
628		}
629		skb_dst_set(skb2, &rt->dst);
630	} else {
631		if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos,
632				   skb2->dev) ||
633		    skb_dst(skb2)->dev->type != ARPHRD_TUNNEL6)
634			goto out;
635	}
636
637	/* change mtu on this route */
638	if (rel_type == ICMP_DEST_UNREACH && rel_code == ICMP_FRAG_NEEDED) {
639		if (rel_info > dst_mtu(skb_dst(skb2)))
640			goto out;
641
642		skb_dst_update_pmtu_no_confirm(skb2, rel_info);
643	}
644
645	icmp_send(skb2, rel_type, rel_code, htonl(rel_info));
646
647out:
648	kfree_skb(skb2);
649	return 0;
650}
651
652static int
653ip6ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
654	   u8 type, u8 code, int offset, __be32 info)
655{
656	__u32 rel_info = ntohl(info);
657	int err, rel_msg = 0;
658	u8 rel_type = type;
659	u8 rel_code = code;
660
661	err = ip6_tnl_err(skb, IPPROTO_IPV6, opt, &rel_type, &rel_code,
662			  &rel_msg, &rel_info, offset);
663	if (err < 0)
664		return err;
665
666	if (rel_msg && pskb_may_pull(skb, offset + sizeof(struct ipv6hdr))) {
667		struct rt6_info *rt;
668		struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
669
670		if (!skb2)
671			return 0;
672
673		skb_dst_drop(skb2);
674		skb_pull(skb2, offset);
675		skb_reset_network_header(skb2);
676
677		/* Try to guess incoming interface */
678		rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr,
679				NULL, 0, skb2, 0);
680
681		if (rt && rt->dst.dev)
682			skb2->dev = rt->dst.dev;
683
684		icmpv6_send(skb2, rel_type, rel_code, rel_info);
685
686		ip6_rt_put(rt);
687
688		kfree_skb(skb2);
689	}
690
691	return 0;
692}
693
694static int
695mplsip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
696	    u8 type, u8 code, int offset, __be32 info)
697{
698	__u32 rel_info = ntohl(info);
699	int err, rel_msg = 0;
700	u8 rel_type = type;
701	u8 rel_code = code;
702
703	err = ip6_tnl_err(skb, IPPROTO_MPLS, opt, &rel_type, &rel_code,
704			  &rel_msg, &rel_info, offset);
705	return err;
706}
707
708static int ip4ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
709				       const struct ipv6hdr *ipv6h,
710				       struct sk_buff *skb)
711{
712	__u8 dsfield = ipv6_get_dsfield(ipv6h) & ~INET_ECN_MASK;
713
714	if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
715		ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, dsfield);
716
717	return IP6_ECN_decapsulate(ipv6h, skb);
718}
719
720static int ip6ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
721				       const struct ipv6hdr *ipv6h,
722				       struct sk_buff *skb)
723{
724	if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
725		ipv6_copy_dscp(ipv6_get_dsfield(ipv6h), ipv6_hdr(skb));
726
727	return IP6_ECN_decapsulate(ipv6h, skb);
728}
729
730static inline int mplsip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
731					       const struct ipv6hdr *ipv6h,
732					       struct sk_buff *skb)
733{
734	/* ECN is not supported in AF_MPLS */
735	return 0;
736}
737
738__u32 ip6_tnl_get_cap(struct ip6_tnl *t,
739			     const struct in6_addr *laddr,
740			     const struct in6_addr *raddr)
741{
742	struct __ip6_tnl_parm *p = &t->parms;
743	int ltype = ipv6_addr_type(laddr);
744	int rtype = ipv6_addr_type(raddr);
745	__u32 flags = 0;
746
747	if (ltype == IPV6_ADDR_ANY || rtype == IPV6_ADDR_ANY) {
748		flags = IP6_TNL_F_CAP_PER_PACKET;
749	} else if (ltype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
750		   rtype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
751		   !((ltype|rtype) & IPV6_ADDR_LOOPBACK) &&
752		   (!((ltype|rtype) & IPV6_ADDR_LINKLOCAL) || p->link)) {
753		if (ltype&IPV6_ADDR_UNICAST)
754			flags |= IP6_TNL_F_CAP_XMIT;
755		if (rtype&IPV6_ADDR_UNICAST)
756			flags |= IP6_TNL_F_CAP_RCV;
757	}
758	return flags;
759}
760EXPORT_SYMBOL(ip6_tnl_get_cap);
761
762/* called with rcu_read_lock() */
763int ip6_tnl_rcv_ctl(struct ip6_tnl *t,
764				  const struct in6_addr *laddr,
765				  const struct in6_addr *raddr)
766{
767	struct __ip6_tnl_parm *p = &t->parms;
768	int ret = 0;
769	struct net *net = t->net;
770
771	if ((p->flags & IP6_TNL_F_CAP_RCV) ||
772	    ((p->flags & IP6_TNL_F_CAP_PER_PACKET) &&
773	     (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_RCV))) {
774		struct net_device *ldev = NULL;
775
776		if (p->link)
777			ldev = dev_get_by_index_rcu(net, p->link);
778
779		if ((ipv6_addr_is_multicast(laddr) ||
780		     likely(ipv6_chk_addr_and_flags(net, laddr, ldev, false,
781						    0, IFA_F_TENTATIVE))) &&
782		    ((p->flags & IP6_TNL_F_ALLOW_LOCAL_REMOTE) ||
783		     likely(!ipv6_chk_addr_and_flags(net, raddr, ldev, true,
784						     0, IFA_F_TENTATIVE))))
785			ret = 1;
786	}
787	return ret;
788}
789EXPORT_SYMBOL_GPL(ip6_tnl_rcv_ctl);
790
791static int __ip6_tnl_rcv(struct ip6_tnl *tunnel, struct sk_buff *skb,
792			 const struct tnl_ptk_info *tpi,
793			 struct metadata_dst *tun_dst,
794			 int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
795						const struct ipv6hdr *ipv6h,
796						struct sk_buff *skb),
797			 bool log_ecn_err)
798{
799	const struct ipv6hdr *ipv6h;
800	int nh, err;
801
802	if ((!(tpi->flags & TUNNEL_CSUM) &&
803	     (tunnel->parms.i_flags & TUNNEL_CSUM)) ||
804	    ((tpi->flags & TUNNEL_CSUM) &&
805	     !(tunnel->parms.i_flags & TUNNEL_CSUM))) {
806		DEV_STATS_INC(tunnel->dev, rx_crc_errors);
807		DEV_STATS_INC(tunnel->dev, rx_errors);
808		goto drop;
809	}
810
811	if (tunnel->parms.i_flags & TUNNEL_SEQ) {
812		if (!(tpi->flags & TUNNEL_SEQ) ||
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
883drop:
884	if (tun_dst)
885		dst_release((struct dst_entry *)tun_dst);
886	kfree_skb(skb);
887	return 0;
888}
889
890int 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}
906EXPORT_SYMBOL(ip6_tnl_rcv);
907
908static const struct tnl_ptk_info tpi_v6 = {
909	/* no tunnel info required for ipxip6. */
910	.proto = htons(ETH_P_IPV6),
911};
912
913static const struct tnl_ptk_info tpi_v4 = {
914	/* no tunnel info required for ipxip6. */
915	.proto = htons(ETH_P_IP),
916};
917
918static const struct tnl_ptk_info tpi_mpls = {
919	/* no tunnel info required for mplsip6. */
920	.proto = htons(ETH_P_MPLS_UC),
921};
922
923static 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			tun_dst = ipv6_tun_rx_dst(skb, 0, 0, 0);
951			if (!tun_dst)
952				goto drop;
953		}
954		ret = __ip6_tnl_rcv(t, skb, tpi, tun_dst, dscp_ecn_decapsulate,
955				    log_ecn_error);
956	}
957
958	rcu_read_unlock();
959
960	return ret;
961
962drop:
963	rcu_read_unlock();
964	kfree_skb(skb);
965	return 0;
966}
967
968static int ip4ip6_rcv(struct sk_buff *skb)
969{
970	return ipxip6_rcv(skb, IPPROTO_IPIP, &tpi_v4,
971			  ip4ip6_dscp_ecn_decapsulate);
972}
973
974static int ip6ip6_rcv(struct sk_buff *skb)
975{
976	return ipxip6_rcv(skb, IPPROTO_IPV6, &tpi_v6,
977			  ip6ip6_dscp_ecn_decapsulate);
978}
979
980static int mplsip6_rcv(struct sk_buff *skb)
981{
982	return ipxip6_rcv(skb, IPPROTO_MPLS, &tpi_mpls,
983			  mplsip6_dscp_ecn_decapsulate);
984}
985
986struct ipv6_tel_txoption {
987	struct ipv6_txoptions ops;
988	__u8 dst_opt[8];
989};
990
991static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit)
992{
993	memset(opt, 0, sizeof(struct ipv6_tel_txoption));
994
995	opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT;
996	opt->dst_opt[3] = 1;
997	opt->dst_opt[4] = encap_limit;
998	opt->dst_opt[5] = IPV6_TLV_PADN;
999	opt->dst_opt[6] = 1;
1000
1001	opt->ops.dst1opt = (struct ipv6_opt_hdr *) opt->dst_opt;
1002	opt->ops.opt_nflen = 8;
1003}
1004
1005/**
1006 * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
1007 *   @t: the outgoing tunnel device
1008 *   @hdr: IPv6 header from the incoming packet
1009 *
1010 * Description:
1011 *   Avoid trivial tunneling loop by checking that tunnel exit-point
1012 *   doesn't match source of incoming packet.
1013 *
1014 * Return:
1015 *   1 if conflict,
1016 *   0 else
1017 **/
1018
1019static inline bool
1020ip6_tnl_addr_conflict(const struct ip6_tnl *t, const struct ipv6hdr *hdr)
1021{
1022	return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
1023}
1024
1025int ip6_tnl_xmit_ctl(struct ip6_tnl *t,
1026		     const struct in6_addr *laddr,
1027		     const struct in6_addr *raddr)
1028{
1029	struct __ip6_tnl_parm *p = &t->parms;
1030	int ret = 0;
1031	struct net *net = t->net;
1032
1033	if (t->parms.collect_md)
1034		return 1;
1035
1036	if ((p->flags & IP6_TNL_F_CAP_XMIT) ||
1037	    ((p->flags & IP6_TNL_F_CAP_PER_PACKET) &&
1038	     (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_XMIT))) {
1039		struct net_device *ldev = NULL;
1040
1041		rcu_read_lock();
1042		if (p->link)
1043			ldev = dev_get_by_index_rcu(net, p->link);
1044
1045		if (unlikely(!ipv6_chk_addr_and_flags(net, laddr, ldev, false,
1046						      0, IFA_F_TENTATIVE)))
1047			pr_warn_ratelimited("%s xmit: Local address not yet configured!\n",
1048					    p->name);
1049		else if (!(p->flags & IP6_TNL_F_ALLOW_LOCAL_REMOTE) &&
1050			 !ipv6_addr_is_multicast(raddr) &&
1051			 unlikely(ipv6_chk_addr_and_flags(net, raddr, ldev,
1052							  true, 0, IFA_F_TENTATIVE)))
1053			pr_warn_ratelimited("%s xmit: Routing loop! Remote address found on this node!\n",
1054					    p->name);
1055		else
1056			ret = 1;
1057		rcu_read_unlock();
1058	}
1059	return ret;
1060}
1061EXPORT_SYMBOL_GPL(ip6_tnl_xmit_ctl);
1062
1063/**
1064 * ip6_tnl_xmit - encapsulate packet and send
1065 *   @skb: the outgoing socket buffer
1066 *   @dev: the outgoing tunnel device
1067 *   @dsfield: dscp code for outer header
1068 *   @fl6: flow of tunneled packet
1069 *   @encap_limit: encapsulation limit
1070 *   @pmtu: Path MTU is stored if packet is too big
1071 *   @proto: next header value
1072 *
1073 * Description:
1074 *   Build new header and do some sanity checks on the packet before sending
1075 *   it.
1076 *
1077 * Return:
1078 *   0 on success
1079 *   -1 fail
1080 *   %-EMSGSIZE message too big. return mtu in this case.
1081 **/
1082
1083int ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev, __u8 dsfield,
1084		 struct flowi6 *fl6, int encap_limit, __u32 *pmtu,
1085		 __u8 proto)
1086{
1087	struct ip6_tnl *t = netdev_priv(dev);
1088	struct net *net = t->net;
1089	struct ipv6hdr *ipv6h;
1090	struct ipv6_tel_txoption opt;
1091	struct dst_entry *dst = NULL, *ndst = NULL;
1092	struct net_device *tdev;
1093	int mtu;
1094	unsigned int eth_hlen = t->dev->type == ARPHRD_ETHER ? ETH_HLEN : 0;
1095	unsigned int psh_hlen = sizeof(struct ipv6hdr) + t->encap_hlen;
1096	unsigned int max_headroom = psh_hlen;
1097	__be16 payload_protocol;
1098	bool use_cache = false;
1099	u8 hop_limit;
1100	int err = -1;
1101
1102	payload_protocol = skb_protocol(skb, true);
1103
1104	if (t->parms.collect_md) {
1105		hop_limit = skb_tunnel_info(skb)->key.ttl;
1106		goto route_lookup;
1107	} else {
1108		hop_limit = t->parms.hop_limit;
1109	}
1110
1111	/* NBMA tunnel */
1112	if (ipv6_addr_any(&t->parms.raddr)) {
1113		if (payload_protocol == htons(ETH_P_IPV6)) {
1114			struct in6_addr *addr6;
1115			struct neighbour *neigh;
1116			int addr_type;
1117
1118			if (!skb_dst(skb))
1119				goto tx_err_link_failure;
1120
1121			neigh = dst_neigh_lookup(skb_dst(skb),
1122						 &ipv6_hdr(skb)->daddr);
1123			if (!neigh)
1124				goto tx_err_link_failure;
1125
1126			addr6 = (struct in6_addr *)&neigh->primary_key;
1127			addr_type = ipv6_addr_type(addr6);
1128
1129			if (addr_type == IPV6_ADDR_ANY)
1130				addr6 = &ipv6_hdr(skb)->daddr;
1131
1132			memcpy(&fl6->daddr, addr6, sizeof(fl6->daddr));
1133			neigh_release(neigh);
1134		} else if (payload_protocol == htons(ETH_P_IP)) {
1135			const struct rtable *rt = skb_rtable(skb);
1136
1137			if (!rt)
1138				goto tx_err_link_failure;
1139
1140			if (rt->rt_gw_family == AF_INET6)
1141				memcpy(&fl6->daddr, &rt->rt_gw6, sizeof(fl6->daddr));
1142		}
1143	} else if (t->parms.proto != 0 && !(t->parms.flags &
1144					    (IP6_TNL_F_USE_ORIG_TCLASS |
1145					     IP6_TNL_F_USE_ORIG_FWMARK))) {
1146		/* enable the cache only if neither the outer protocol nor the
1147		 * routing decision depends on the current inner header value
1148		 */
1149		use_cache = true;
1150	}
1151
1152	if (use_cache)
1153		dst = dst_cache_get(&t->dst_cache);
1154
1155	if (!ip6_tnl_xmit_ctl(t, &fl6->saddr, &fl6->daddr))
1156		goto tx_err_link_failure;
1157
1158	if (!dst) {
1159route_lookup:
1160		/* add dsfield to flowlabel for route lookup */
1161		fl6->flowlabel = ip6_make_flowinfo(dsfield, fl6->flowlabel);
1162
1163		dst = ip6_route_output(net, NULL, fl6);
1164
1165		if (dst->error)
1166			goto tx_err_link_failure;
1167		dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), NULL, 0);
1168		if (IS_ERR(dst)) {
1169			err = PTR_ERR(dst);
1170			dst = NULL;
1171			goto tx_err_link_failure;
1172		}
1173		if (t->parms.collect_md && ipv6_addr_any(&fl6->saddr) &&
1174		    ipv6_dev_get_saddr(net, ip6_dst_idev(dst)->dev,
1175				       &fl6->daddr, 0, &fl6->saddr))
1176			goto tx_err_link_failure;
1177		ndst = dst;
1178	}
1179
1180	tdev = dst->dev;
1181
1182	if (tdev == dev) {
1183		DEV_STATS_INC(dev, collisions);
1184		net_warn_ratelimited("%s: Local routing loop detected!\n",
1185				     t->parms.name);
1186		goto tx_err_dst_release;
1187	}
1188	mtu = dst_mtu(dst) - eth_hlen - psh_hlen - t->tun_hlen;
1189	if (encap_limit >= 0) {
1190		max_headroom += 8;
1191		mtu -= 8;
1192	}
1193	mtu = max(mtu, skb->protocol == htons(ETH_P_IPV6) ?
1194		       IPV6_MIN_MTU : IPV4_MIN_MTU);
1195
1196	skb_dst_update_pmtu_no_confirm(skb, mtu);
1197	if (skb->len - t->tun_hlen - eth_hlen > mtu && !skb_is_gso(skb)) {
1198		*pmtu = mtu;
1199		err = -EMSGSIZE;
1200		goto tx_err_dst_release;
1201	}
1202
1203	if (t->err_count > 0) {
1204		if (time_before(jiffies,
1205				t->err_time + IP6TUNNEL_ERR_TIMEO)) {
1206			t->err_count--;
1207
1208			dst_link_failure(skb);
1209		} else {
1210			t->err_count = 0;
1211		}
1212	}
1213
1214	skb_scrub_packet(skb, !net_eq(t->net, dev_net(dev)));
1215
1216	/*
1217	 * Okay, now see if we can stuff it in the buffer as-is.
1218	 */
1219	max_headroom += LL_RESERVED_SPACE(tdev);
1220
1221	if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
1222	    (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
1223		struct sk_buff *new_skb;
1224
1225		new_skb = skb_realloc_headroom(skb, max_headroom);
1226		if (!new_skb)
1227			goto tx_err_dst_release;
1228
1229		if (skb->sk)
1230			skb_set_owner_w(new_skb, skb->sk);
1231		consume_skb(skb);
1232		skb = new_skb;
1233	}
1234
1235	if (t->parms.collect_md) {
1236		if (t->encap.type != TUNNEL_ENCAP_NONE)
1237			goto tx_err_dst_release;
1238	} else {
1239		if (use_cache && ndst)
1240			dst_cache_set_ip6(&t->dst_cache, ndst, &fl6->saddr);
1241	}
1242	skb_dst_set(skb, dst);
1243
1244	if (hop_limit == 0) {
1245		if (payload_protocol == htons(ETH_P_IP))
1246			hop_limit = ip_hdr(skb)->ttl;
1247		else if (payload_protocol == htons(ETH_P_IPV6))
1248			hop_limit = ipv6_hdr(skb)->hop_limit;
1249		else
1250			hop_limit = ip6_dst_hoplimit(dst);
1251	}
1252
1253	/* Calculate max headroom for all the headers and adjust
1254	 * needed_headroom if necessary.
1255	 */
1256	max_headroom = LL_RESERVED_SPACE(dst->dev) + sizeof(struct ipv6hdr)
1257			+ dst->header_len + t->hlen;
1258	if (max_headroom > READ_ONCE(dev->needed_headroom))
1259		WRITE_ONCE(dev->needed_headroom, max_headroom);
1260
1261	err = ip6_tnl_encap(skb, t, &proto, fl6);
1262	if (err)
1263		return err;
1264
1265	if (encap_limit >= 0) {
1266		init_tel_txopt(&opt, encap_limit);
1267		ipv6_push_frag_opts(skb, &opt.ops, &proto);
1268	}
1269
1270	skb_push(skb, sizeof(struct ipv6hdr));
1271	skb_reset_network_header(skb);
1272	ipv6h = ipv6_hdr(skb);
1273	ip6_flow_hdr(ipv6h, dsfield,
1274		     ip6_make_flowlabel(net, skb, fl6->flowlabel, true, fl6));
1275	ipv6h->hop_limit = hop_limit;
1276	ipv6h->nexthdr = proto;
1277	ipv6h->saddr = fl6->saddr;
1278	ipv6h->daddr = fl6->daddr;
1279	ip6tunnel_xmit(NULL, skb, dev);
1280	return 0;
1281tx_err_link_failure:
1282	DEV_STATS_INC(dev, tx_carrier_errors);
1283	dst_link_failure(skb);
1284tx_err_dst_release:
1285	dst_release(dst);
1286	return err;
1287}
1288EXPORT_SYMBOL(ip6_tnl_xmit);
1289
1290static inline int
1291ipxip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev,
1292		u8 protocol)
1293{
1294	struct ip6_tnl *t = netdev_priv(dev);
1295	struct ipv6hdr *ipv6h;
1296	const struct iphdr  *iph;
1297	int encap_limit = -1;
1298	__u16 offset;
1299	struct flowi6 fl6;
1300	__u8 dsfield, orig_dsfield;
1301	__u32 mtu;
1302	u8 tproto;
1303	int err;
1304
1305	tproto = READ_ONCE(t->parms.proto);
1306	if (tproto != protocol && tproto != 0)
1307		return -1;
1308
1309	if (t->parms.collect_md) {
1310		struct ip_tunnel_info *tun_info;
1311		const struct ip_tunnel_key *key;
1312
1313		tun_info = skb_tunnel_info(skb);
1314		if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
1315			     ip_tunnel_info_af(tun_info) != AF_INET6))
1316			return -1;
1317		key = &tun_info->key;
1318		memset(&fl6, 0, sizeof(fl6));
1319		fl6.flowi6_proto = protocol;
1320		fl6.saddr = key->u.ipv6.src;
1321		fl6.daddr = key->u.ipv6.dst;
1322		fl6.flowlabel = key->label;
1323		dsfield =  key->tos;
1324		switch (protocol) {
1325		case IPPROTO_IPIP:
1326			iph = ip_hdr(skb);
1327			orig_dsfield = ipv4_get_dsfield(iph);
1328			break;
1329		case IPPROTO_IPV6:
1330			ipv6h = ipv6_hdr(skb);
1331			orig_dsfield = ipv6_get_dsfield(ipv6h);
1332			break;
1333		default:
1334			orig_dsfield = dsfield;
1335			break;
1336		}
1337	} else {
1338		if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1339			encap_limit = t->parms.encap_limit;
1340		if (protocol == IPPROTO_IPV6) {
1341			offset = ip6_tnl_parse_tlv_enc_lim(skb,
1342						skb_network_header(skb));
1343			/* ip6_tnl_parse_tlv_enc_lim() might have
1344			 * reallocated skb->head
1345			 */
1346			if (offset > 0) {
1347				struct ipv6_tlv_tnl_enc_lim *tel;
1348
1349				tel = (void *)&skb_network_header(skb)[offset];
1350				if (tel->encap_limit == 0) {
1351					icmpv6_ndo_send(skb, ICMPV6_PARAMPROB,
1352							ICMPV6_HDR_FIELD, offset + 2);
1353					return -1;
1354				}
1355				encap_limit = tel->encap_limit - 1;
1356			}
1357		}
1358
1359		memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
1360		fl6.flowi6_proto = protocol;
1361
1362		if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
1363			fl6.flowi6_mark = skb->mark;
1364		else
1365			fl6.flowi6_mark = t->parms.fwmark;
1366		switch (protocol) {
1367		case IPPROTO_IPIP:
1368			iph = ip_hdr(skb);
1369			orig_dsfield = ipv4_get_dsfield(iph);
1370			if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1371				dsfield = orig_dsfield;
1372			else
1373				dsfield = ip6_tclass(t->parms.flowinfo);
1374			break;
1375		case IPPROTO_IPV6:
1376			ipv6h = ipv6_hdr(skb);
1377			orig_dsfield = ipv6_get_dsfield(ipv6h);
1378			if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1379				dsfield = orig_dsfield;
1380			else
1381				dsfield = ip6_tclass(t->parms.flowinfo);
1382			if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
1383				fl6.flowlabel |= ip6_flowlabel(ipv6h);
1384			break;
1385		default:
1386			orig_dsfield = dsfield = ip6_tclass(t->parms.flowinfo);
1387			break;
1388		}
1389	}
1390
1391	fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
1392	dsfield = INET_ECN_encapsulate(dsfield, orig_dsfield);
1393
1394	if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP6))
1395		return -1;
1396
1397	skb_set_inner_ipproto(skb, protocol);
1398
1399	err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
1400			   protocol);
1401	if (err != 0) {
1402		/* XXX: send ICMP error even if DF is not set. */
1403		if (err == -EMSGSIZE)
1404			switch (protocol) {
1405			case IPPROTO_IPIP:
1406				icmp_ndo_send(skb, ICMP_DEST_UNREACH,
1407					      ICMP_FRAG_NEEDED, htonl(mtu));
1408				break;
1409			case IPPROTO_IPV6:
1410				icmpv6_ndo_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
1411				break;
1412			default:
1413				break;
1414			}
1415		return -1;
1416	}
1417
1418	return 0;
1419}
1420
1421static netdev_tx_t
1422ip6_tnl_start_xmit(struct sk_buff *skb, struct net_device *dev)
1423{
1424	struct ip6_tnl *t = netdev_priv(dev);
1425	u8 ipproto;
1426	int ret;
1427
1428	if (!pskb_inet_may_pull(skb))
1429		goto tx_err;
1430
1431	switch (skb->protocol) {
1432	case htons(ETH_P_IP):
1433		ipproto = IPPROTO_IPIP;
1434		break;
1435	case htons(ETH_P_IPV6):
1436		if (ip6_tnl_addr_conflict(t, ipv6_hdr(skb)))
1437			goto tx_err;
1438		ipproto = IPPROTO_IPV6;
1439		break;
1440	case htons(ETH_P_MPLS_UC):
1441		ipproto = IPPROTO_MPLS;
1442		break;
1443	default:
1444		goto tx_err;
1445	}
1446
1447	ret = ipxip6_tnl_xmit(skb, dev, ipproto);
1448	if (ret < 0)
1449		goto tx_err;
1450
1451	return NETDEV_TX_OK;
1452
1453tx_err:
1454	DEV_STATS_INC(dev, tx_errors);
1455	DEV_STATS_INC(dev, tx_dropped);
1456	kfree_skb(skb);
1457	return NETDEV_TX_OK;
1458}
1459
1460static void ip6_tnl_link_config(struct ip6_tnl *t)
1461{
1462	struct net_device *dev = t->dev;
1463	struct net_device *tdev = NULL;
1464	struct __ip6_tnl_parm *p = &t->parms;
1465	struct flowi6 *fl6 = &t->fl.u.ip6;
1466	int t_hlen;
1467	int mtu;
1468
1469	__dev_addr_set(dev, &p->laddr, sizeof(struct in6_addr));
1470	memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
1471
1472	/* Set up flowi template */
1473	fl6->saddr = p->laddr;
1474	fl6->daddr = p->raddr;
1475	fl6->flowi6_oif = p->link;
1476	fl6->flowlabel = 0;
1477
1478	if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
1479		fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
1480	if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
1481		fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
1482
1483	p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
1484	p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
1485
1486	if (p->flags&IP6_TNL_F_CAP_XMIT && p->flags&IP6_TNL_F_CAP_RCV)
1487		dev->flags |= IFF_POINTOPOINT;
1488	else
1489		dev->flags &= ~IFF_POINTOPOINT;
1490
1491	t->tun_hlen = 0;
1492	t->hlen = t->encap_hlen + t->tun_hlen;
1493	t_hlen = t->hlen + sizeof(struct ipv6hdr);
1494
1495	if (p->flags & IP6_TNL_F_CAP_XMIT) {
1496		int strict = (ipv6_addr_type(&p->raddr) &
1497			      (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
1498
1499		struct rt6_info *rt = rt6_lookup(t->net,
1500						 &p->raddr, &p->laddr,
1501						 p->link, NULL, strict);
1502		if (rt) {
1503			tdev = rt->dst.dev;
1504			ip6_rt_put(rt);
1505		}
1506
1507		if (!tdev && p->link)
1508			tdev = __dev_get_by_index(t->net, p->link);
1509
1510		if (tdev) {
1511			dev->hard_header_len = tdev->hard_header_len + t_hlen;
1512			mtu = min_t(unsigned int, tdev->mtu, IP6_MAX_MTU);
1513
1514			mtu = mtu - t_hlen;
1515			if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1516				mtu -= 8;
1517
1518			if (mtu < IPV6_MIN_MTU)
1519				mtu = IPV6_MIN_MTU;
1520			WRITE_ONCE(dev->mtu, mtu);
1521		}
1522	}
1523}
1524
1525/**
1526 * ip6_tnl_change - update the tunnel parameters
1527 *   @t: tunnel to be changed
1528 *   @p: tunnel configuration parameters
1529 *
1530 * Description:
1531 *   ip6_tnl_change() updates the tunnel parameters
1532 **/
1533
1534static void
1535ip6_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p)
1536{
1537	t->parms.laddr = p->laddr;
1538	t->parms.raddr = p->raddr;
1539	t->parms.flags = p->flags;
1540	t->parms.hop_limit = p->hop_limit;
1541	t->parms.encap_limit = p->encap_limit;
1542	t->parms.flowinfo = p->flowinfo;
1543	t->parms.link = p->link;
1544	t->parms.proto = p->proto;
1545	t->parms.fwmark = p->fwmark;
1546	dst_cache_reset(&t->dst_cache);
1547	ip6_tnl_link_config(t);
1548}
1549
1550static void ip6_tnl_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
1551{
1552	struct net *net = t->net;
1553	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1554
1555	ip6_tnl_unlink(ip6n, t);
1556	synchronize_net();
1557	ip6_tnl_change(t, p);
1558	ip6_tnl_link(ip6n, t);
1559	netdev_state_change(t->dev);
1560}
1561
1562static void ip6_tnl0_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
1563{
1564	/* for default tnl0 device allow to change only the proto */
1565	t->parms.proto = p->proto;
1566	netdev_state_change(t->dev);
1567}
1568
1569static void
1570ip6_tnl_parm_from_user(struct __ip6_tnl_parm *p, const struct ip6_tnl_parm *u)
1571{
1572	p->laddr = u->laddr;
1573	p->raddr = u->raddr;
1574	p->flags = u->flags;
1575	p->hop_limit = u->hop_limit;
1576	p->encap_limit = u->encap_limit;
1577	p->flowinfo = u->flowinfo;
1578	p->link = u->link;
1579	p->proto = u->proto;
1580	memcpy(p->name, u->name, sizeof(u->name));
1581}
1582
1583static void
1584ip6_tnl_parm_to_user(struct ip6_tnl_parm *u, const struct __ip6_tnl_parm *p)
1585{
1586	u->laddr = p->laddr;
1587	u->raddr = p->raddr;
1588	u->flags = p->flags;
1589	u->hop_limit = p->hop_limit;
1590	u->encap_limit = p->encap_limit;
1591	u->flowinfo = p->flowinfo;
1592	u->link = p->link;
1593	u->proto = p->proto;
1594	memcpy(u->name, p->name, sizeof(u->name));
1595}
1596
1597/**
1598 * ip6_tnl_siocdevprivate - configure ipv6 tunnels from userspace
1599 *   @dev: virtual device associated with tunnel
1600 *   @ifr: unused
1601 *   @data: parameters passed from userspace
1602 *   @cmd: command to be performed
1603 *
1604 * Description:
1605 *   ip6_tnl_ioctl() is used for managing IPv6 tunnels
1606 *   from userspace.
1607 *
1608 *   The possible commands are the following:
1609 *     %SIOCGETTUNNEL: get tunnel parameters for device
1610 *     %SIOCADDTUNNEL: add tunnel matching given tunnel parameters
1611 *     %SIOCCHGTUNNEL: change tunnel parameters to those given
1612 *     %SIOCDELTUNNEL: delete tunnel
1613 *
1614 *   The fallback device "ip6tnl0", created during module
1615 *   initialization, can be used for creating other tunnel devices.
1616 *
1617 * Return:
1618 *   0 on success,
1619 *   %-EFAULT if unable to copy data to or from userspace,
1620 *   %-EPERM if current process hasn't %CAP_NET_ADMIN set
1621 *   %-EINVAL if passed tunnel parameters are invalid,
1622 *   %-EEXIST if changing a tunnel's parameters would cause a conflict
1623 *   %-ENODEV if attempting to change or delete a nonexisting device
1624 **/
1625
1626static int
1627ip6_tnl_siocdevprivate(struct net_device *dev, struct ifreq *ifr,
1628		       void __user *data, int cmd)
1629{
1630	int err = 0;
1631	struct ip6_tnl_parm p;
1632	struct __ip6_tnl_parm p1;
1633	struct ip6_tnl *t = netdev_priv(dev);
1634	struct net *net = t->net;
1635	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1636
1637	memset(&p1, 0, sizeof(p1));
1638
1639	switch (cmd) {
1640	case SIOCGETTUNNEL:
1641		if (dev == ip6n->fb_tnl_dev) {
1642			if (copy_from_user(&p, data, sizeof(p))) {
1643				err = -EFAULT;
1644				break;
1645			}
1646			ip6_tnl_parm_from_user(&p1, &p);
1647			t = ip6_tnl_locate(net, &p1, 0);
1648			if (IS_ERR(t))
1649				t = netdev_priv(dev);
1650		} else {
1651			memset(&p, 0, sizeof(p));
1652		}
1653		ip6_tnl_parm_to_user(&p, &t->parms);
1654		if (copy_to_user(data, &p, sizeof(p)))
1655			err = -EFAULT;
1656		break;
1657	case SIOCADDTUNNEL:
1658	case SIOCCHGTUNNEL:
1659		err = -EPERM;
1660		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1661			break;
1662		err = -EFAULT;
1663		if (copy_from_user(&p, data, sizeof(p)))
1664			break;
1665		err = -EINVAL;
1666		if (p.proto != IPPROTO_IPV6 && p.proto != IPPROTO_IPIP &&
1667		    p.proto != 0)
1668			break;
1669		ip6_tnl_parm_from_user(&p1, &p);
1670		t = ip6_tnl_locate(net, &p1, cmd == SIOCADDTUNNEL);
1671		if (cmd == SIOCCHGTUNNEL) {
1672			if (!IS_ERR(t)) {
1673				if (t->dev != dev) {
1674					err = -EEXIST;
1675					break;
1676				}
1677			} else
1678				t = netdev_priv(dev);
1679			if (dev == ip6n->fb_tnl_dev)
1680				ip6_tnl0_update(t, &p1);
1681			else
1682				ip6_tnl_update(t, &p1);
1683		}
1684		if (!IS_ERR(t)) {
1685			err = 0;
1686			ip6_tnl_parm_to_user(&p, &t->parms);
1687			if (copy_to_user(data, &p, sizeof(p)))
1688				err = -EFAULT;
1689
1690		} else {
1691			err = PTR_ERR(t);
1692		}
1693		break;
1694	case SIOCDELTUNNEL:
1695		err = -EPERM;
1696		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1697			break;
1698
1699		if (dev == ip6n->fb_tnl_dev) {
1700			err = -EFAULT;
1701			if (copy_from_user(&p, data, sizeof(p)))
1702				break;
1703			err = -ENOENT;
1704			ip6_tnl_parm_from_user(&p1, &p);
1705			t = ip6_tnl_locate(net, &p1, 0);
1706			if (IS_ERR(t))
1707				break;
1708			err = -EPERM;
1709			if (t->dev == ip6n->fb_tnl_dev)
1710				break;
1711			dev = t->dev;
1712		}
1713		err = 0;
1714		unregister_netdevice(dev);
1715		break;
1716	default:
1717		err = -EINVAL;
1718	}
1719	return err;
1720}
1721
1722/**
1723 * ip6_tnl_change_mtu - change mtu manually for tunnel device
1724 *   @dev: virtual device associated with tunnel
1725 *   @new_mtu: the new mtu
1726 *
1727 * Return:
1728 *   0 on success,
1729 *   %-EINVAL if mtu too small
1730 **/
1731
1732int ip6_tnl_change_mtu(struct net_device *dev, int new_mtu)
1733{
1734	struct ip6_tnl *tnl = netdev_priv(dev);
1735
1736	if (tnl->parms.proto == IPPROTO_IPV6) {
1737		if (new_mtu < IPV6_MIN_MTU)
1738			return -EINVAL;
1739	} else {
1740		if (new_mtu < ETH_MIN_MTU)
1741			return -EINVAL;
1742	}
1743	if (tnl->parms.proto == IPPROTO_IPV6 || tnl->parms.proto == 0) {
1744		if (new_mtu > IP6_MAX_MTU - dev->hard_header_len)
1745			return -EINVAL;
1746	} else {
1747		if (new_mtu > IP_MAX_MTU - dev->hard_header_len)
1748			return -EINVAL;
1749	}
1750	dev->mtu = new_mtu;
1751	return 0;
1752}
1753EXPORT_SYMBOL(ip6_tnl_change_mtu);
1754
1755int ip6_tnl_get_iflink(const struct net_device *dev)
1756{
1757	struct ip6_tnl *t = netdev_priv(dev);
1758
1759	return t->parms.link;
1760}
1761EXPORT_SYMBOL(ip6_tnl_get_iflink);
1762
1763int ip6_tnl_encap_add_ops(const struct ip6_tnl_encap_ops *ops,
1764			  unsigned int num)
1765{
1766	if (num >= MAX_IPTUN_ENCAP_OPS)
1767		return -ERANGE;
1768
1769	return !cmpxchg((const struct ip6_tnl_encap_ops **)
1770			&ip6tun_encaps[num],
1771			NULL, ops) ? 0 : -1;
1772}
1773EXPORT_SYMBOL(ip6_tnl_encap_add_ops);
1774
1775int ip6_tnl_encap_del_ops(const struct ip6_tnl_encap_ops *ops,
1776			  unsigned int num)
1777{
1778	int ret;
1779
1780	if (num >= MAX_IPTUN_ENCAP_OPS)
1781		return -ERANGE;
1782
1783	ret = (cmpxchg((const struct ip6_tnl_encap_ops **)
1784		       &ip6tun_encaps[num],
1785		       ops, NULL) == ops) ? 0 : -1;
1786
1787	synchronize_net();
1788
1789	return ret;
1790}
1791EXPORT_SYMBOL(ip6_tnl_encap_del_ops);
1792
1793int ip6_tnl_encap_setup(struct ip6_tnl *t,
1794			struct ip_tunnel_encap *ipencap)
1795{
1796	int hlen;
1797
1798	memset(&t->encap, 0, sizeof(t->encap));
1799
1800	hlen = ip6_encap_hlen(ipencap);
1801	if (hlen < 0)
1802		return hlen;
1803
1804	t->encap.type = ipencap->type;
1805	t->encap.sport = ipencap->sport;
1806	t->encap.dport = ipencap->dport;
1807	t->encap.flags = ipencap->flags;
1808
1809	t->encap_hlen = hlen;
1810	t->hlen = t->encap_hlen + t->tun_hlen;
1811
1812	return 0;
1813}
1814EXPORT_SYMBOL_GPL(ip6_tnl_encap_setup);
1815
1816static const struct net_device_ops ip6_tnl_netdev_ops = {
1817	.ndo_init	= ip6_tnl_dev_init,
1818	.ndo_uninit	= ip6_tnl_dev_uninit,
1819	.ndo_start_xmit = ip6_tnl_start_xmit,
1820	.ndo_siocdevprivate = ip6_tnl_siocdevprivate,
1821	.ndo_change_mtu = ip6_tnl_change_mtu,
1822	.ndo_get_stats64 = dev_get_tstats64,
1823	.ndo_get_iflink = ip6_tnl_get_iflink,
1824};
1825
1826#define IPXIPX_FEATURES (NETIF_F_SG |		\
1827			 NETIF_F_FRAGLIST |	\
1828			 NETIF_F_HIGHDMA |	\
1829			 NETIF_F_GSO_SOFTWARE |	\
1830			 NETIF_F_HW_CSUM)
1831
1832/**
1833 * ip6_tnl_dev_setup - setup virtual tunnel device
1834 *   @dev: virtual device associated with tunnel
1835 *
1836 * Description:
1837 *   Initialize function pointers and device parameters
1838 **/
1839
1840static void ip6_tnl_dev_setup(struct net_device *dev)
1841{
1842	dev->netdev_ops = &ip6_tnl_netdev_ops;
1843	dev->header_ops = &ip_tunnel_header_ops;
1844	dev->needs_free_netdev = true;
1845	dev->priv_destructor = ip6_dev_free;
1846
1847	dev->type = ARPHRD_TUNNEL6;
1848	dev->flags |= IFF_NOARP;
1849	dev->addr_len = sizeof(struct in6_addr);
1850	dev->features |= NETIF_F_LLTX;
1851	netif_keep_dst(dev);
1852
1853	dev->features		|= IPXIPX_FEATURES;
1854	dev->hw_features	|= IPXIPX_FEATURES;
1855
1856	/* This perm addr will be used as interface identifier by IPv6 */
1857	dev->addr_assign_type = NET_ADDR_RANDOM;
1858	eth_random_addr(dev->perm_addr);
1859}
1860
1861
1862/**
1863 * ip6_tnl_dev_init_gen - general initializer for all tunnel devices
1864 *   @dev: virtual device associated with tunnel
1865 **/
1866
1867static inline int
1868ip6_tnl_dev_init_gen(struct net_device *dev)
1869{
1870	struct ip6_tnl *t = netdev_priv(dev);
1871	int ret;
1872	int t_hlen;
1873
1874	t->dev = dev;
1875	t->net = dev_net(dev);
1876	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1877	if (!dev->tstats)
1878		return -ENOMEM;
1879
1880	ret = dst_cache_init(&t->dst_cache, GFP_KERNEL);
1881	if (ret)
1882		goto free_stats;
1883
1884	ret = gro_cells_init(&t->gro_cells, dev);
1885	if (ret)
1886		goto destroy_dst;
1887
1888	t->tun_hlen = 0;
1889	t->hlen = t->encap_hlen + t->tun_hlen;
1890	t_hlen = t->hlen + sizeof(struct ipv6hdr);
1891
1892	dev->type = ARPHRD_TUNNEL6;
1893	dev->hard_header_len = LL_MAX_HEADER + t_hlen;
1894	dev->mtu = ETH_DATA_LEN - t_hlen;
1895	if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1896		dev->mtu -= 8;
1897	dev->min_mtu = ETH_MIN_MTU;
1898	dev->max_mtu = IP6_MAX_MTU - dev->hard_header_len;
1899
1900	netdev_hold(dev, &t->dev_tracker, GFP_KERNEL);
1901	return 0;
1902
1903destroy_dst:
1904	dst_cache_destroy(&t->dst_cache);
1905free_stats:
1906	free_percpu(dev->tstats);
1907	dev->tstats = NULL;
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
1917static 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
1937static 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
1949static 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
1966static 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
2005static 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
2041static 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
2075static 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
2084static 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
2118static 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
2146nla_put_failure:
2147	return -EMSGSIZE;
2148}
2149
2150struct net *ip6_tnl_get_link_net(const struct net_device *dev)
2151{
2152	struct ip6_tnl *tunnel = netdev_priv(dev);
2153
2154	return tunnel->net;
2155}
2156EXPORT_SYMBOL(ip6_tnl_get_link_net);
2157
2158static 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
2175static 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
2190static struct xfrm6_tunnel ip4ip6_handler __read_mostly = {
2191	.handler	= ip4ip6_rcv,
2192	.err_handler	= ip4ip6_err,
2193	.priority	=	1,
2194};
2195
2196static struct xfrm6_tunnel ip6ip6_handler __read_mostly = {
2197	.handler	= ip6ip6_rcv,
2198	.err_handler	= ip6ip6_err,
2199	.priority	=	1,
2200};
2201
2202static struct xfrm6_tunnel mplsip6_handler __read_mostly = {
2203	.handler	= mplsip6_rcv,
2204	.err_handler	= mplsip6_err,
2205	.priority	=	1,
2206};
2207
2208static 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
2242static 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->features |= NETIF_F_NETNS_LOCAL;
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
2279err_register:
2280	free_netdev(ip6n->fb_tnl_dev);
2281err_alloc_dev:
2282	return err;
2283}
2284
2285static void __net_exit ip6_tnl_exit_batch_net(struct list_head *net_list)
2286{
2287	struct net *net;
2288	LIST_HEAD(list);
2289
2290	rtnl_lock();
2291	list_for_each_entry(net, net_list, exit_list)
2292		ip6_tnl_destroy_tunnels(net, &list);
2293	unregister_netdevice_many(&list);
2294	rtnl_unlock();
2295}
2296
2297static struct pernet_operations ip6_tnl_net_ops = {
2298	.init = ip6_tnl_init_net,
2299	.exit_batch = ip6_tnl_exit_batch_net,
2300	.id   = &ip6_tnl_net_id,
2301	.size = sizeof(struct ip6_tnl_net),
2302};
2303
2304/**
2305 * ip6_tunnel_init - register protocol and reserve needed resources
2306 *
2307 * Return: 0 on success
2308 **/
2309
2310static int __init ip6_tunnel_init(void)
2311{
2312	int  err;
2313
2314	if (!ipv6_mod_enabled())
2315		return -EOPNOTSUPP;
2316
2317	err = register_pernet_device(&ip6_tnl_net_ops);
2318	if (err < 0)
2319		goto out_pernet;
2320
2321	err = xfrm6_tunnel_register(&ip4ip6_handler, AF_INET);
2322	if (err < 0) {
2323		pr_err("%s: can't register ip4ip6\n", __func__);
2324		goto out_ip4ip6;
2325	}
2326
2327	err = xfrm6_tunnel_register(&ip6ip6_handler, AF_INET6);
2328	if (err < 0) {
2329		pr_err("%s: can't register ip6ip6\n", __func__);
2330		goto out_ip6ip6;
2331	}
2332
2333	if (ip6_tnl_mpls_supported()) {
2334		err = xfrm6_tunnel_register(&mplsip6_handler, AF_MPLS);
2335		if (err < 0) {
2336			pr_err("%s: can't register mplsip6\n", __func__);
2337			goto out_mplsip6;
2338		}
2339	}
2340
2341	err = rtnl_link_register(&ip6_link_ops);
2342	if (err < 0)
2343		goto rtnl_link_failed;
2344
2345	return 0;
2346
2347rtnl_link_failed:
2348	if (ip6_tnl_mpls_supported())
2349		xfrm6_tunnel_deregister(&mplsip6_handler, AF_MPLS);
2350out_mplsip6:
2351	xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6);
2352out_ip6ip6:
2353	xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET);
2354out_ip4ip6:
2355	unregister_pernet_device(&ip6_tnl_net_ops);
2356out_pernet:
2357	return err;
2358}
2359
2360/**
2361 * ip6_tunnel_cleanup - free resources and unregister protocol
2362 **/
2363
2364static void __exit ip6_tunnel_cleanup(void)
2365{
2366	rtnl_link_unregister(&ip6_link_ops);
2367	if (xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET))
2368		pr_info("%s: can't deregister ip4ip6\n", __func__);
2369
2370	if (xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6))
2371		pr_info("%s: can't deregister ip6ip6\n", __func__);
2372
2373	if (ip6_tnl_mpls_supported() &&
2374	    xfrm6_tunnel_deregister(&mplsip6_handler, AF_MPLS))
2375		pr_info("%s: can't deregister mplsip6\n", __func__);
2376	unregister_pernet_device(&ip6_tnl_net_ops);
2377}
2378
2379module_init(ip6_tunnel_init);
2380module_exit(ip6_tunnel_cleanup);
2381