xref: /kernel/linux/linux-6.6/net/ipv6/sit.c (revision 62306a36)
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 *	IPv6 over IPv4 tunnel device - Simple Internet Transition (SIT)
4 *	Linux INET6 implementation
5 *
6 *	Authors:
7 *	Pedro Roque		<roque@di.fc.ul.pt>
8 *	Alexey Kuznetsov	<kuznet@ms2.inr.ac.ru>
9 *
10 *	Changes:
11 * Roger Venning <r.venning@telstra.com>:	6to4 support
12 * Nate Thompson <nate@thebog.net>:		6to4 support
13 * Fred Templin <fred.l.templin@boeing.com>:	isatap support
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/socket.h>
23#include <linux/sockios.h>
24#include <linux/net.h>
25#include <linux/in6.h>
26#include <linux/netdevice.h>
27#include <linux/if_arp.h>
28#include <linux/icmp.h>
29#include <linux/slab.h>
30#include <linux/uaccess.h>
31#include <linux/init.h>
32#include <linux/netfilter_ipv4.h>
33#include <linux/if_ether.h>
34
35#include <net/sock.h>
36#include <net/snmp.h>
37
38#include <net/ipv6.h>
39#include <net/protocol.h>
40#include <net/transp_v6.h>
41#include <net/ip6_fib.h>
42#include <net/ip6_route.h>
43#include <net/ndisc.h>
44#include <net/addrconf.h>
45#include <net/ip.h>
46#include <net/udp.h>
47#include <net/icmp.h>
48#include <net/ip_tunnels.h>
49#include <net/inet_ecn.h>
50#include <net/xfrm.h>
51#include <net/dsfield.h>
52#include <net/net_namespace.h>
53#include <net/netns/generic.h>
54
55/*
56   This version of net/ipv6/sit.c is cloned of net/ipv4/ip_gre.c
57
58   For comments look at net/ipv4/ip_gre.c --ANK
59 */
60
61#define IP6_SIT_HASH_SIZE  16
62#define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF)
63
64static bool log_ecn_error = true;
65module_param(log_ecn_error, bool, 0644);
66MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
67
68static int ipip6_tunnel_init(struct net_device *dev);
69static void ipip6_tunnel_setup(struct net_device *dev);
70static void ipip6_dev_free(struct net_device *dev);
71static bool check_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst,
72		      __be32 *v4dst);
73static struct rtnl_link_ops sit_link_ops __read_mostly;
74
75static unsigned int sit_net_id __read_mostly;
76struct sit_net {
77	struct ip_tunnel __rcu *tunnels_r_l[IP6_SIT_HASH_SIZE];
78	struct ip_tunnel __rcu *tunnels_r[IP6_SIT_HASH_SIZE];
79	struct ip_tunnel __rcu *tunnels_l[IP6_SIT_HASH_SIZE];
80	struct ip_tunnel __rcu *tunnels_wc[1];
81	struct ip_tunnel __rcu **tunnels[4];
82
83	struct net_device *fb_tunnel_dev;
84};
85
86static inline struct sit_net *dev_to_sit_net(struct net_device *dev)
87{
88	struct ip_tunnel *t = netdev_priv(dev);
89
90	return net_generic(t->net, sit_net_id);
91}
92
93/*
94 * Must be invoked with rcu_read_lock
95 */
96static struct ip_tunnel *ipip6_tunnel_lookup(struct net *net,
97					     struct net_device *dev,
98					     __be32 remote, __be32 local,
99					     int sifindex)
100{
101	unsigned int h0 = HASH(remote);
102	unsigned int h1 = HASH(local);
103	struct ip_tunnel *t;
104	struct sit_net *sitn = net_generic(net, sit_net_id);
105	int ifindex = dev ? dev->ifindex : 0;
106
107	for_each_ip_tunnel_rcu(t, sitn->tunnels_r_l[h0 ^ h1]) {
108		if (local == t->parms.iph.saddr &&
109		    remote == t->parms.iph.daddr &&
110		    (!dev || !t->parms.link || ifindex == t->parms.link ||
111		     sifindex == t->parms.link) &&
112		    (t->dev->flags & IFF_UP))
113			return t;
114	}
115	for_each_ip_tunnel_rcu(t, sitn->tunnels_r[h0]) {
116		if (remote == t->parms.iph.daddr &&
117		    (!dev || !t->parms.link || ifindex == t->parms.link ||
118		     sifindex == t->parms.link) &&
119		    (t->dev->flags & IFF_UP))
120			return t;
121	}
122	for_each_ip_tunnel_rcu(t, sitn->tunnels_l[h1]) {
123		if (local == t->parms.iph.saddr &&
124		    (!dev || !t->parms.link || ifindex == t->parms.link ||
125		     sifindex == t->parms.link) &&
126		    (t->dev->flags & IFF_UP))
127			return t;
128	}
129	t = rcu_dereference(sitn->tunnels_wc[0]);
130	if (t && (t->dev->flags & IFF_UP))
131		return t;
132	return NULL;
133}
134
135static struct ip_tunnel __rcu **__ipip6_bucket(struct sit_net *sitn,
136		struct ip_tunnel_parm *parms)
137{
138	__be32 remote = parms->iph.daddr;
139	__be32 local = parms->iph.saddr;
140	unsigned int h = 0;
141	int prio = 0;
142
143	if (remote) {
144		prio |= 2;
145		h ^= HASH(remote);
146	}
147	if (local) {
148		prio |= 1;
149		h ^= HASH(local);
150	}
151	return &sitn->tunnels[prio][h];
152}
153
154static inline struct ip_tunnel __rcu **ipip6_bucket(struct sit_net *sitn,
155		struct ip_tunnel *t)
156{
157	return __ipip6_bucket(sitn, &t->parms);
158}
159
160static void ipip6_tunnel_unlink(struct sit_net *sitn, struct ip_tunnel *t)
161{
162	struct ip_tunnel __rcu **tp;
163	struct ip_tunnel *iter;
164
165	for (tp = ipip6_bucket(sitn, t);
166	     (iter = rtnl_dereference(*tp)) != NULL;
167	     tp = &iter->next) {
168		if (t == iter) {
169			rcu_assign_pointer(*tp, t->next);
170			break;
171		}
172	}
173}
174
175static void ipip6_tunnel_link(struct sit_net *sitn, struct ip_tunnel *t)
176{
177	struct ip_tunnel __rcu **tp = ipip6_bucket(sitn, t);
178
179	rcu_assign_pointer(t->next, rtnl_dereference(*tp));
180	rcu_assign_pointer(*tp, t);
181}
182
183static void ipip6_tunnel_clone_6rd(struct net_device *dev, struct sit_net *sitn)
184{
185#ifdef CONFIG_IPV6_SIT_6RD
186	struct ip_tunnel *t = netdev_priv(dev);
187
188	if (dev == sitn->fb_tunnel_dev || !sitn->fb_tunnel_dev) {
189		ipv6_addr_set(&t->ip6rd.prefix, htonl(0x20020000), 0, 0, 0);
190		t->ip6rd.relay_prefix = 0;
191		t->ip6rd.prefixlen = 16;
192		t->ip6rd.relay_prefixlen = 0;
193	} else {
194		struct ip_tunnel *t0 = netdev_priv(sitn->fb_tunnel_dev);
195		memcpy(&t->ip6rd, &t0->ip6rd, sizeof(t->ip6rd));
196	}
197#endif
198}
199
200static int ipip6_tunnel_create(struct net_device *dev)
201{
202	struct ip_tunnel *t = netdev_priv(dev);
203	struct net *net = dev_net(dev);
204	struct sit_net *sitn = net_generic(net, sit_net_id);
205	int err;
206
207	__dev_addr_set(dev, &t->parms.iph.saddr, 4);
208	memcpy(dev->broadcast, &t->parms.iph.daddr, 4);
209
210	if ((__force u16)t->parms.i_flags & SIT_ISATAP)
211		dev->priv_flags |= IFF_ISATAP;
212
213	dev->rtnl_link_ops = &sit_link_ops;
214
215	err = register_netdevice(dev);
216	if (err < 0)
217		goto out;
218
219	ipip6_tunnel_clone_6rd(dev, sitn);
220
221	ipip6_tunnel_link(sitn, t);
222	return 0;
223
224out:
225	return err;
226}
227
228static struct ip_tunnel *ipip6_tunnel_locate(struct net *net,
229		struct ip_tunnel_parm *parms, int create)
230{
231	__be32 remote = parms->iph.daddr;
232	__be32 local = parms->iph.saddr;
233	struct ip_tunnel *t, *nt;
234	struct ip_tunnel __rcu **tp;
235	struct net_device *dev;
236	char name[IFNAMSIZ];
237	struct sit_net *sitn = net_generic(net, sit_net_id);
238
239	for (tp = __ipip6_bucket(sitn, parms);
240	    (t = rtnl_dereference(*tp)) != NULL;
241	     tp = &t->next) {
242		if (local == t->parms.iph.saddr &&
243		    remote == t->parms.iph.daddr &&
244		    parms->link == t->parms.link) {
245			if (create)
246				return NULL;
247			else
248				return t;
249		}
250	}
251	if (!create)
252		goto failed;
253
254	if (parms->name[0]) {
255		if (!dev_valid_name(parms->name))
256			goto failed;
257		strscpy(name, parms->name, IFNAMSIZ);
258	} else {
259		strcpy(name, "sit%d");
260	}
261	dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
262			   ipip6_tunnel_setup);
263	if (!dev)
264		return NULL;
265
266	dev_net_set(dev, net);
267
268	nt = netdev_priv(dev);
269
270	nt->parms = *parms;
271	if (ipip6_tunnel_create(dev) < 0)
272		goto failed_free;
273
274	if (!parms->name[0])
275		strcpy(parms->name, dev->name);
276
277	return nt;
278
279failed_free:
280	free_netdev(dev);
281failed:
282	return NULL;
283}
284
285#define for_each_prl_rcu(start)			\
286	for (prl = rcu_dereference(start);	\
287	     prl;				\
288	     prl = rcu_dereference(prl->next))
289
290static struct ip_tunnel_prl_entry *
291__ipip6_tunnel_locate_prl(struct ip_tunnel *t, __be32 addr)
292{
293	struct ip_tunnel_prl_entry *prl;
294
295	for_each_prl_rcu(t->prl)
296		if (prl->addr == addr)
297			break;
298	return prl;
299
300}
301
302static int ipip6_tunnel_get_prl(struct net_device *dev, struct ip_tunnel_prl __user *a)
303{
304	struct ip_tunnel *t = netdev_priv(dev);
305	struct ip_tunnel_prl kprl, *kp;
306	struct ip_tunnel_prl_entry *prl;
307	unsigned int cmax, c = 0, ca, len;
308	int ret = 0;
309
310	if (dev == dev_to_sit_net(dev)->fb_tunnel_dev)
311		return -EINVAL;
312
313	if (copy_from_user(&kprl, a, sizeof(kprl)))
314		return -EFAULT;
315	cmax = kprl.datalen / sizeof(kprl);
316	if (cmax > 1 && kprl.addr != htonl(INADDR_ANY))
317		cmax = 1;
318
319	/* For simple GET or for root users,
320	 * we try harder to allocate.
321	 */
322	kp = (cmax <= 1 || capable(CAP_NET_ADMIN)) ?
323		kcalloc(cmax, sizeof(*kp), GFP_KERNEL_ACCOUNT | __GFP_NOWARN) :
324		NULL;
325
326	ca = min(t->prl_count, cmax);
327
328	if (!kp) {
329		/* We don't try hard to allocate much memory for
330		 * non-root users.
331		 * For root users, retry allocating enough memory for
332		 * the answer.
333		 */
334		kp = kcalloc(ca, sizeof(*kp), GFP_ATOMIC | __GFP_ACCOUNT |
335					      __GFP_NOWARN);
336		if (!kp) {
337			ret = -ENOMEM;
338			goto out;
339		}
340	}
341
342	rcu_read_lock();
343	for_each_prl_rcu(t->prl) {
344		if (c >= cmax)
345			break;
346		if (kprl.addr != htonl(INADDR_ANY) && prl->addr != kprl.addr)
347			continue;
348		kp[c].addr = prl->addr;
349		kp[c].flags = prl->flags;
350		c++;
351		if (kprl.addr != htonl(INADDR_ANY))
352			break;
353	}
354
355	rcu_read_unlock();
356
357	len = sizeof(*kp) * c;
358	ret = 0;
359	if ((len && copy_to_user(a + 1, kp, len)) || put_user(len, &a->datalen))
360		ret = -EFAULT;
361
362	kfree(kp);
363out:
364	return ret;
365}
366
367static int
368ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg)
369{
370	struct ip_tunnel_prl_entry *p;
371	int err = 0;
372
373	if (a->addr == htonl(INADDR_ANY))
374		return -EINVAL;
375
376	ASSERT_RTNL();
377
378	for (p = rtnl_dereference(t->prl); p; p = rtnl_dereference(p->next)) {
379		if (p->addr == a->addr) {
380			if (chg) {
381				p->flags = a->flags;
382				goto out;
383			}
384			err = -EEXIST;
385			goto out;
386		}
387	}
388
389	if (chg) {
390		err = -ENXIO;
391		goto out;
392	}
393
394	p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL);
395	if (!p) {
396		err = -ENOBUFS;
397		goto out;
398	}
399
400	p->next = t->prl;
401	p->addr = a->addr;
402	p->flags = a->flags;
403	t->prl_count++;
404	rcu_assign_pointer(t->prl, p);
405out:
406	return err;
407}
408
409static void prl_list_destroy_rcu(struct rcu_head *head)
410{
411	struct ip_tunnel_prl_entry *p, *n;
412
413	p = container_of(head, struct ip_tunnel_prl_entry, rcu_head);
414	do {
415		n = rcu_dereference_protected(p->next, 1);
416		kfree(p);
417		p = n;
418	} while (p);
419}
420
421static int
422ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a)
423{
424	struct ip_tunnel_prl_entry *x;
425	struct ip_tunnel_prl_entry __rcu **p;
426	int err = 0;
427
428	ASSERT_RTNL();
429
430	if (a && a->addr != htonl(INADDR_ANY)) {
431		for (p = &t->prl;
432		     (x = rtnl_dereference(*p)) != NULL;
433		     p = &x->next) {
434			if (x->addr == a->addr) {
435				*p = x->next;
436				kfree_rcu(x, rcu_head);
437				t->prl_count--;
438				goto out;
439			}
440		}
441		err = -ENXIO;
442	} else {
443		x = rtnl_dereference(t->prl);
444		if (x) {
445			t->prl_count = 0;
446			call_rcu(&x->rcu_head, prl_list_destroy_rcu);
447			t->prl = NULL;
448		}
449	}
450out:
451	return err;
452}
453
454static int ipip6_tunnel_prl_ctl(struct net_device *dev,
455				struct ip_tunnel_prl __user *data, int cmd)
456{
457	struct ip_tunnel *t = netdev_priv(dev);
458	struct ip_tunnel_prl prl;
459	int err;
460
461	if (!ns_capable(t->net->user_ns, CAP_NET_ADMIN))
462		return -EPERM;
463	if (dev == dev_to_sit_net(dev)->fb_tunnel_dev)
464		return -EINVAL;
465
466	if (copy_from_user(&prl, data, sizeof(prl)))
467		return -EFAULT;
468
469	switch (cmd) {
470	case SIOCDELPRL:
471		err = ipip6_tunnel_del_prl(t, &prl);
472		break;
473	case SIOCADDPRL:
474	case SIOCCHGPRL:
475		err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL);
476		break;
477	}
478	dst_cache_reset(&t->dst_cache);
479	netdev_state_change(dev);
480	return err;
481}
482
483static int
484isatap_chksrc(struct sk_buff *skb, const struct iphdr *iph, struct ip_tunnel *t)
485{
486	struct ip_tunnel_prl_entry *p;
487	int ok = 1;
488
489	rcu_read_lock();
490	p = __ipip6_tunnel_locate_prl(t, iph->saddr);
491	if (p) {
492		if (p->flags & PRL_DEFAULT)
493			skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT;
494		else
495			skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT;
496	} else {
497		const struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr;
498
499		if (ipv6_addr_is_isatap(addr6) &&
500		    (addr6->s6_addr32[3] == iph->saddr) &&
501		    ipv6_chk_prefix(addr6, t->dev))
502			skb->ndisc_nodetype = NDISC_NODETYPE_HOST;
503		else
504			ok = 0;
505	}
506	rcu_read_unlock();
507	return ok;
508}
509
510static void ipip6_tunnel_uninit(struct net_device *dev)
511{
512	struct ip_tunnel *tunnel = netdev_priv(dev);
513	struct sit_net *sitn = net_generic(tunnel->net, sit_net_id);
514
515	if (dev == sitn->fb_tunnel_dev) {
516		RCU_INIT_POINTER(sitn->tunnels_wc[0], NULL);
517	} else {
518		ipip6_tunnel_unlink(sitn, tunnel);
519		ipip6_tunnel_del_prl(tunnel, NULL);
520	}
521	dst_cache_reset(&tunnel->dst_cache);
522	netdev_put(dev, &tunnel->dev_tracker);
523}
524
525static int ipip6_err(struct sk_buff *skb, u32 info)
526{
527	const struct iphdr *iph = (const struct iphdr *)skb->data;
528	const int type = icmp_hdr(skb)->type;
529	const int code = icmp_hdr(skb)->code;
530	unsigned int data_len = 0;
531	struct ip_tunnel *t;
532	int sifindex;
533	int err;
534
535	switch (type) {
536	default:
537	case ICMP_PARAMETERPROB:
538		return 0;
539
540	case ICMP_DEST_UNREACH:
541		switch (code) {
542		case ICMP_SR_FAILED:
543			/* Impossible event. */
544			return 0;
545		default:
546			/* All others are translated to HOST_UNREACH.
547			   rfc2003 contains "deep thoughts" about NET_UNREACH,
548			   I believe they are just ether pollution. --ANK
549			 */
550			break;
551		}
552		break;
553	case ICMP_TIME_EXCEEDED:
554		if (code != ICMP_EXC_TTL)
555			return 0;
556		data_len = icmp_hdr(skb)->un.reserved[1] * 4; /* RFC 4884 4.1 */
557		break;
558	case ICMP_REDIRECT:
559		break;
560	}
561
562	err = -ENOENT;
563
564	sifindex = netif_is_l3_master(skb->dev) ? IPCB(skb)->iif : 0;
565	t = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
566				iph->daddr, iph->saddr, sifindex);
567	if (!t)
568		goto out;
569
570	if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
571		ipv4_update_pmtu(skb, dev_net(skb->dev), info,
572				 t->parms.link, iph->protocol);
573		err = 0;
574		goto out;
575	}
576	if (type == ICMP_REDIRECT) {
577		ipv4_redirect(skb, dev_net(skb->dev), t->parms.link,
578			      iph->protocol);
579		err = 0;
580		goto out;
581	}
582
583	err = 0;
584	if (__in6_dev_get(skb->dev) &&
585	    !ip6_err_gen_icmpv6_unreach(skb, iph->ihl * 4, type, data_len))
586		goto out;
587
588	if (t->parms.iph.daddr == 0)
589		goto out;
590
591	if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
592		goto out;
593
594	if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
595		t->err_count++;
596	else
597		t->err_count = 1;
598	t->err_time = jiffies;
599out:
600	return err;
601}
602
603static inline bool is_spoofed_6rd(struct ip_tunnel *tunnel, const __be32 v4addr,
604				  const struct in6_addr *v6addr)
605{
606	__be32 v4embed = 0;
607	if (check_6rd(tunnel, v6addr, &v4embed) && v4addr != v4embed)
608		return true;
609	return false;
610}
611
612/* Checks if an address matches an address on the tunnel interface.
613 * Used to detect the NAT of proto 41 packets and let them pass spoofing test.
614 * Long story:
615 * This function is called after we considered the packet as spoofed
616 * in is_spoofed_6rd.
617 * We may have a router that is doing NAT for proto 41 packets
618 * for an internal station. Destination a.a.a.a/PREFIX:bbbb:bbbb
619 * will be translated to n.n.n.n/PREFIX:bbbb:bbbb. And is_spoofed_6rd
620 * function will return true, dropping the packet.
621 * But, we can still check if is spoofed against the IP
622 * addresses associated with the interface.
623 */
624static bool only_dnatted(const struct ip_tunnel *tunnel,
625	const struct in6_addr *v6dst)
626{
627	int prefix_len;
628
629#ifdef CONFIG_IPV6_SIT_6RD
630	prefix_len = tunnel->ip6rd.prefixlen + 32
631		- tunnel->ip6rd.relay_prefixlen;
632#else
633	prefix_len = 48;
634#endif
635	return ipv6_chk_custom_prefix(v6dst, prefix_len, tunnel->dev);
636}
637
638/* Returns true if a packet is spoofed */
639static bool packet_is_spoofed(struct sk_buff *skb,
640			      const struct iphdr *iph,
641			      struct ip_tunnel *tunnel)
642{
643	const struct ipv6hdr *ipv6h;
644
645	if (tunnel->dev->priv_flags & IFF_ISATAP) {
646		if (!isatap_chksrc(skb, iph, tunnel))
647			return true;
648
649		return false;
650	}
651
652	if (tunnel->dev->flags & IFF_POINTOPOINT)
653		return false;
654
655	ipv6h = ipv6_hdr(skb);
656
657	if (unlikely(is_spoofed_6rd(tunnel, iph->saddr, &ipv6h->saddr))) {
658		net_warn_ratelimited("Src spoofed %pI4/%pI6c -> %pI4/%pI6c\n",
659				     &iph->saddr, &ipv6h->saddr,
660				     &iph->daddr, &ipv6h->daddr);
661		return true;
662	}
663
664	if (likely(!is_spoofed_6rd(tunnel, iph->daddr, &ipv6h->daddr)))
665		return false;
666
667	if (only_dnatted(tunnel, &ipv6h->daddr))
668		return false;
669
670	net_warn_ratelimited("Dst spoofed %pI4/%pI6c -> %pI4/%pI6c\n",
671			     &iph->saddr, &ipv6h->saddr,
672			     &iph->daddr, &ipv6h->daddr);
673	return true;
674}
675
676static int ipip6_rcv(struct sk_buff *skb)
677{
678	const struct iphdr *iph = ip_hdr(skb);
679	struct ip_tunnel *tunnel;
680	int sifindex;
681	int err;
682
683	sifindex = netif_is_l3_master(skb->dev) ? IPCB(skb)->iif : 0;
684	tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
685				     iph->saddr, iph->daddr, sifindex);
686	if (tunnel) {
687		if (tunnel->parms.iph.protocol != IPPROTO_IPV6 &&
688		    tunnel->parms.iph.protocol != 0)
689			goto out;
690
691		skb->mac_header = skb->network_header;
692		skb_reset_network_header(skb);
693		IPCB(skb)->flags = 0;
694		skb->dev = tunnel->dev;
695
696		if (packet_is_spoofed(skb, iph, tunnel)) {
697			DEV_STATS_INC(tunnel->dev, rx_errors);
698			goto out;
699		}
700
701		if (iptunnel_pull_header(skb, 0, htons(ETH_P_IPV6),
702		    !net_eq(tunnel->net, dev_net(tunnel->dev))))
703			goto out;
704
705		/* skb can be uncloned in iptunnel_pull_header, so
706		 * old iph is no longer valid
707		 */
708		iph = (const struct iphdr *)skb_mac_header(skb);
709		skb_reset_mac_header(skb);
710
711		err = IP_ECN_decapsulate(iph, skb);
712		if (unlikely(err)) {
713			if (log_ecn_error)
714				net_info_ratelimited("non-ECT from %pI4 with TOS=%#x\n",
715						     &iph->saddr, iph->tos);
716			if (err > 1) {
717				DEV_STATS_INC(tunnel->dev, rx_frame_errors);
718				DEV_STATS_INC(tunnel->dev, rx_errors);
719				goto out;
720			}
721		}
722
723		dev_sw_netstats_rx_add(tunnel->dev, skb->len);
724
725		netif_rx(skb);
726
727		return 0;
728	}
729
730	/* no tunnel matched,  let upstream know, ipsec may handle it */
731	return 1;
732out:
733	kfree_skb(skb);
734	return 0;
735}
736
737static const struct tnl_ptk_info ipip_tpi = {
738	/* no tunnel info required for ipip. */
739	.proto = htons(ETH_P_IP),
740};
741
742#if IS_ENABLED(CONFIG_MPLS)
743static const struct tnl_ptk_info mplsip_tpi = {
744	/* no tunnel info required for mplsip. */
745	.proto = htons(ETH_P_MPLS_UC),
746};
747#endif
748
749static int sit_tunnel_rcv(struct sk_buff *skb, u8 ipproto)
750{
751	const struct iphdr *iph;
752	struct ip_tunnel *tunnel;
753	int sifindex;
754
755	sifindex = netif_is_l3_master(skb->dev) ? IPCB(skb)->iif : 0;
756
757	iph = ip_hdr(skb);
758	tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
759				     iph->saddr, iph->daddr, sifindex);
760	if (tunnel) {
761		const struct tnl_ptk_info *tpi;
762
763		if (tunnel->parms.iph.protocol != ipproto &&
764		    tunnel->parms.iph.protocol != 0)
765			goto drop;
766
767		if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
768			goto drop;
769#if IS_ENABLED(CONFIG_MPLS)
770		if (ipproto == IPPROTO_MPLS)
771			tpi = &mplsip_tpi;
772		else
773#endif
774			tpi = &ipip_tpi;
775		if (iptunnel_pull_header(skb, 0, tpi->proto, false))
776			goto drop;
777		skb_reset_mac_header(skb);
778
779		return ip_tunnel_rcv(tunnel, skb, tpi, NULL, log_ecn_error);
780	}
781
782	return 1;
783
784drop:
785	kfree_skb(skb);
786	return 0;
787}
788
789static int ipip_rcv(struct sk_buff *skb)
790{
791	return sit_tunnel_rcv(skb, IPPROTO_IPIP);
792}
793
794#if IS_ENABLED(CONFIG_MPLS)
795static int mplsip_rcv(struct sk_buff *skb)
796{
797	return sit_tunnel_rcv(skb, IPPROTO_MPLS);
798}
799#endif
800
801/*
802 * If the IPv6 address comes from 6rd / 6to4 (RFC 3056) addr space this function
803 * stores the embedded IPv4 address in v4dst and returns true.
804 */
805static bool check_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst,
806		      __be32 *v4dst)
807{
808#ifdef CONFIG_IPV6_SIT_6RD
809	if (ipv6_prefix_equal(v6dst, &tunnel->ip6rd.prefix,
810			      tunnel->ip6rd.prefixlen)) {
811		unsigned int pbw0, pbi0;
812		int pbi1;
813		u32 d;
814
815		pbw0 = tunnel->ip6rd.prefixlen >> 5;
816		pbi0 = tunnel->ip6rd.prefixlen & 0x1f;
817
818		d = tunnel->ip6rd.relay_prefixlen < 32 ?
819			(ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >>
820		    tunnel->ip6rd.relay_prefixlen : 0;
821
822		pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen;
823		if (pbi1 > 0)
824			d |= ntohl(v6dst->s6_addr32[pbw0 + 1]) >>
825			     (32 - pbi1);
826
827		*v4dst = tunnel->ip6rd.relay_prefix | htonl(d);
828		return true;
829	}
830#else
831	if (v6dst->s6_addr16[0] == htons(0x2002)) {
832		/* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */
833		memcpy(v4dst, &v6dst->s6_addr16[1], 4);
834		return true;
835	}
836#endif
837	return false;
838}
839
840static inline __be32 try_6rd(struct ip_tunnel *tunnel,
841			     const struct in6_addr *v6dst)
842{
843	__be32 dst = 0;
844	check_6rd(tunnel, v6dst, &dst);
845	return dst;
846}
847
848/*
849 *	This function assumes it is being called from dev_queue_xmit()
850 *	and that skb is filled properly by that function.
851 */
852
853static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
854				     struct net_device *dev)
855{
856	struct ip_tunnel *tunnel = netdev_priv(dev);
857	const struct iphdr  *tiph = &tunnel->parms.iph;
858	const struct ipv6hdr *iph6 = ipv6_hdr(skb);
859	u8     tos = tunnel->parms.iph.tos;
860	__be16 df = tiph->frag_off;
861	struct rtable *rt;		/* Route to the other host */
862	struct net_device *tdev;	/* Device to other host */
863	unsigned int max_headroom;	/* The extra header space needed */
864	__be32 dst = tiph->daddr;
865	struct flowi4 fl4;
866	int    mtu;
867	const struct in6_addr *addr6;
868	int addr_type;
869	u8 ttl;
870	u8 protocol = IPPROTO_IPV6;
871	int t_hlen = tunnel->hlen + sizeof(struct iphdr);
872
873	if (tos == 1)
874		tos = ipv6_get_dsfield(iph6);
875
876	/* ISATAP (RFC4214) - must come before 6to4 */
877	if (dev->priv_flags & IFF_ISATAP) {
878		struct neighbour *neigh = NULL;
879		bool do_tx_error = false;
880
881		if (skb_dst(skb))
882			neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr);
883
884		if (!neigh) {
885			net_dbg_ratelimited("nexthop == NULL\n");
886			goto tx_error;
887		}
888
889		addr6 = (const struct in6_addr *)&neigh->primary_key;
890		addr_type = ipv6_addr_type(addr6);
891
892		if ((addr_type & IPV6_ADDR_UNICAST) &&
893		     ipv6_addr_is_isatap(addr6))
894			dst = addr6->s6_addr32[3];
895		else
896			do_tx_error = true;
897
898		neigh_release(neigh);
899		if (do_tx_error)
900			goto tx_error;
901	}
902
903	if (!dst)
904		dst = try_6rd(tunnel, &iph6->daddr);
905
906	if (!dst) {
907		struct neighbour *neigh = NULL;
908		bool do_tx_error = false;
909
910		if (skb_dst(skb))
911			neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr);
912
913		if (!neigh) {
914			net_dbg_ratelimited("nexthop == NULL\n");
915			goto tx_error;
916		}
917
918		addr6 = (const struct in6_addr *)&neigh->primary_key;
919		addr_type = ipv6_addr_type(addr6);
920
921		if (addr_type == IPV6_ADDR_ANY) {
922			addr6 = &ipv6_hdr(skb)->daddr;
923			addr_type = ipv6_addr_type(addr6);
924		}
925
926		if ((addr_type & IPV6_ADDR_COMPATv4) != 0)
927			dst = addr6->s6_addr32[3];
928		else
929			do_tx_error = true;
930
931		neigh_release(neigh);
932		if (do_tx_error)
933			goto tx_error;
934	}
935
936	flowi4_init_output(&fl4, tunnel->parms.link, tunnel->fwmark,
937			   RT_TOS(tos), RT_SCOPE_UNIVERSE, IPPROTO_IPV6,
938			   0, dst, tiph->saddr, 0, 0,
939			   sock_net_uid(tunnel->net, NULL));
940
941	rt = dst_cache_get_ip4(&tunnel->dst_cache, &fl4.saddr);
942	if (!rt) {
943		rt = ip_route_output_flow(tunnel->net, &fl4, NULL);
944		if (IS_ERR(rt)) {
945			DEV_STATS_INC(dev, tx_carrier_errors);
946			goto tx_error_icmp;
947		}
948		dst_cache_set_ip4(&tunnel->dst_cache, &rt->dst, fl4.saddr);
949	}
950
951	if (rt->rt_type != RTN_UNICAST && rt->rt_type != RTN_LOCAL) {
952		ip_rt_put(rt);
953		DEV_STATS_INC(dev, tx_carrier_errors);
954		goto tx_error_icmp;
955	}
956	tdev = rt->dst.dev;
957
958	if (tdev == dev) {
959		ip_rt_put(rt);
960		DEV_STATS_INC(dev, collisions);
961		goto tx_error;
962	}
963
964	if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP4)) {
965		ip_rt_put(rt);
966		goto tx_error;
967	}
968
969	if (df) {
970		mtu = dst_mtu(&rt->dst) - t_hlen;
971
972		if (mtu < IPV4_MIN_MTU) {
973			DEV_STATS_INC(dev, collisions);
974			ip_rt_put(rt);
975			goto tx_error;
976		}
977
978		if (mtu < IPV6_MIN_MTU) {
979			mtu = IPV6_MIN_MTU;
980			df = 0;
981		}
982
983		if (tunnel->parms.iph.daddr)
984			skb_dst_update_pmtu_no_confirm(skb, mtu);
985
986		if (skb->len > mtu && !skb_is_gso(skb)) {
987			icmpv6_ndo_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
988			ip_rt_put(rt);
989			goto tx_error;
990		}
991	}
992
993	if (tunnel->err_count > 0) {
994		if (time_before(jiffies,
995				tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
996			tunnel->err_count--;
997			dst_link_failure(skb);
998		} else
999			tunnel->err_count = 0;
1000	}
1001
1002	/*
1003	 * Okay, now see if we can stuff it in the buffer as-is.
1004	 */
1005	max_headroom = LL_RESERVED_SPACE(tdev) + t_hlen;
1006
1007	if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
1008	    (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
1009		struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
1010		if (!new_skb) {
1011			ip_rt_put(rt);
1012			DEV_STATS_INC(dev, tx_dropped);
1013			kfree_skb(skb);
1014			return NETDEV_TX_OK;
1015		}
1016		if (skb->sk)
1017			skb_set_owner_w(new_skb, skb->sk);
1018		dev_kfree_skb(skb);
1019		skb = new_skb;
1020		iph6 = ipv6_hdr(skb);
1021	}
1022	ttl = tiph->ttl;
1023	if (ttl == 0)
1024		ttl = iph6->hop_limit;
1025	tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6));
1026
1027	if (ip_tunnel_encap(skb, &tunnel->encap, &protocol, &fl4) < 0) {
1028		ip_rt_put(rt);
1029		goto tx_error;
1030	}
1031
1032	skb_set_inner_ipproto(skb, IPPROTO_IPV6);
1033
1034	iptunnel_xmit(NULL, rt, skb, fl4.saddr, fl4.daddr, protocol, tos, ttl,
1035		      df, !net_eq(tunnel->net, dev_net(dev)));
1036	return NETDEV_TX_OK;
1037
1038tx_error_icmp:
1039	dst_link_failure(skb);
1040tx_error:
1041	kfree_skb(skb);
1042	DEV_STATS_INC(dev, tx_errors);
1043	return NETDEV_TX_OK;
1044}
1045
1046static netdev_tx_t sit_tunnel_xmit__(struct sk_buff *skb,
1047				     struct net_device *dev, u8 ipproto)
1048{
1049	struct ip_tunnel *tunnel = netdev_priv(dev);
1050	const struct iphdr  *tiph = &tunnel->parms.iph;
1051
1052	if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP4))
1053		goto tx_error;
1054
1055	skb_set_inner_ipproto(skb, ipproto);
1056
1057	ip_tunnel_xmit(skb, dev, tiph, ipproto);
1058	return NETDEV_TX_OK;
1059tx_error:
1060	kfree_skb(skb);
1061	DEV_STATS_INC(dev, tx_errors);
1062	return NETDEV_TX_OK;
1063}
1064
1065static netdev_tx_t sit_tunnel_xmit(struct sk_buff *skb,
1066				   struct net_device *dev)
1067{
1068	if (!pskb_inet_may_pull(skb))
1069		goto tx_err;
1070
1071	switch (skb->protocol) {
1072	case htons(ETH_P_IP):
1073		sit_tunnel_xmit__(skb, dev, IPPROTO_IPIP);
1074		break;
1075	case htons(ETH_P_IPV6):
1076		ipip6_tunnel_xmit(skb, dev);
1077		break;
1078#if IS_ENABLED(CONFIG_MPLS)
1079	case htons(ETH_P_MPLS_UC):
1080		sit_tunnel_xmit__(skb, dev, IPPROTO_MPLS);
1081		break;
1082#endif
1083	default:
1084		goto tx_err;
1085	}
1086
1087	return NETDEV_TX_OK;
1088
1089tx_err:
1090	DEV_STATS_INC(dev, tx_errors);
1091	kfree_skb(skb);
1092	return NETDEV_TX_OK;
1093
1094}
1095
1096static void ipip6_tunnel_bind_dev(struct net_device *dev)
1097{
1098	struct ip_tunnel *tunnel = netdev_priv(dev);
1099	int t_hlen = tunnel->hlen + sizeof(struct iphdr);
1100	struct net_device *tdev = NULL;
1101	int hlen = LL_MAX_HEADER;
1102	const struct iphdr *iph;
1103	struct flowi4 fl4;
1104
1105	iph = &tunnel->parms.iph;
1106
1107	if (iph->daddr) {
1108		struct rtable *rt = ip_route_output_ports(tunnel->net, &fl4,
1109							  NULL,
1110							  iph->daddr, iph->saddr,
1111							  0, 0,
1112							  IPPROTO_IPV6,
1113							  RT_TOS(iph->tos),
1114							  tunnel->parms.link);
1115
1116		if (!IS_ERR(rt)) {
1117			tdev = rt->dst.dev;
1118			ip_rt_put(rt);
1119		}
1120		dev->flags |= IFF_POINTOPOINT;
1121	}
1122
1123	if (!tdev && tunnel->parms.link)
1124		tdev = __dev_get_by_index(tunnel->net, tunnel->parms.link);
1125
1126	if (tdev && !netif_is_l3_master(tdev)) {
1127		int mtu;
1128
1129		mtu = tdev->mtu - t_hlen;
1130		if (mtu < IPV6_MIN_MTU)
1131			mtu = IPV6_MIN_MTU;
1132		WRITE_ONCE(dev->mtu, mtu);
1133		hlen = tdev->hard_header_len + tdev->needed_headroom;
1134	}
1135	dev->needed_headroom = t_hlen + hlen;
1136}
1137
1138static void ipip6_tunnel_update(struct ip_tunnel *t, struct ip_tunnel_parm *p,
1139				__u32 fwmark)
1140{
1141	struct net *net = t->net;
1142	struct sit_net *sitn = net_generic(net, sit_net_id);
1143
1144	ipip6_tunnel_unlink(sitn, t);
1145	synchronize_net();
1146	t->parms.iph.saddr = p->iph.saddr;
1147	t->parms.iph.daddr = p->iph.daddr;
1148	__dev_addr_set(t->dev, &p->iph.saddr, 4);
1149	memcpy(t->dev->broadcast, &p->iph.daddr, 4);
1150	ipip6_tunnel_link(sitn, t);
1151	t->parms.iph.ttl = p->iph.ttl;
1152	t->parms.iph.tos = p->iph.tos;
1153	t->parms.iph.frag_off = p->iph.frag_off;
1154	if (t->parms.link != p->link || t->fwmark != fwmark) {
1155		t->parms.link = p->link;
1156		t->fwmark = fwmark;
1157		ipip6_tunnel_bind_dev(t->dev);
1158	}
1159	dst_cache_reset(&t->dst_cache);
1160	netdev_state_change(t->dev);
1161}
1162
1163#ifdef CONFIG_IPV6_SIT_6RD
1164static int ipip6_tunnel_update_6rd(struct ip_tunnel *t,
1165				   struct ip_tunnel_6rd *ip6rd)
1166{
1167	struct in6_addr prefix;
1168	__be32 relay_prefix;
1169
1170	if (ip6rd->relay_prefixlen > 32 ||
1171	    ip6rd->prefixlen + (32 - ip6rd->relay_prefixlen) > 64)
1172		return -EINVAL;
1173
1174	ipv6_addr_prefix(&prefix, &ip6rd->prefix, ip6rd->prefixlen);
1175	if (!ipv6_addr_equal(&prefix, &ip6rd->prefix))
1176		return -EINVAL;
1177	if (ip6rd->relay_prefixlen)
1178		relay_prefix = ip6rd->relay_prefix &
1179			       htonl(0xffffffffUL <<
1180				     (32 - ip6rd->relay_prefixlen));
1181	else
1182		relay_prefix = 0;
1183	if (relay_prefix != ip6rd->relay_prefix)
1184		return -EINVAL;
1185
1186	t->ip6rd.prefix = prefix;
1187	t->ip6rd.relay_prefix = relay_prefix;
1188	t->ip6rd.prefixlen = ip6rd->prefixlen;
1189	t->ip6rd.relay_prefixlen = ip6rd->relay_prefixlen;
1190	dst_cache_reset(&t->dst_cache);
1191	netdev_state_change(t->dev);
1192	return 0;
1193}
1194
1195static int
1196ipip6_tunnel_get6rd(struct net_device *dev, struct ip_tunnel_parm __user *data)
1197{
1198	struct ip_tunnel *t = netdev_priv(dev);
1199	struct ip_tunnel_6rd ip6rd;
1200	struct ip_tunnel_parm p;
1201
1202	if (dev == dev_to_sit_net(dev)->fb_tunnel_dev) {
1203		if (copy_from_user(&p, data, sizeof(p)))
1204			return -EFAULT;
1205		t = ipip6_tunnel_locate(t->net, &p, 0);
1206	}
1207	if (!t)
1208		t = netdev_priv(dev);
1209
1210	ip6rd.prefix = t->ip6rd.prefix;
1211	ip6rd.relay_prefix = t->ip6rd.relay_prefix;
1212	ip6rd.prefixlen = t->ip6rd.prefixlen;
1213	ip6rd.relay_prefixlen = t->ip6rd.relay_prefixlen;
1214	if (copy_to_user(data, &ip6rd, sizeof(ip6rd)))
1215		return -EFAULT;
1216	return 0;
1217}
1218
1219static int
1220ipip6_tunnel_6rdctl(struct net_device *dev, struct ip_tunnel_6rd __user *data,
1221		    int cmd)
1222{
1223	struct ip_tunnel *t = netdev_priv(dev);
1224	struct ip_tunnel_6rd ip6rd;
1225	int err;
1226
1227	if (!ns_capable(t->net->user_ns, CAP_NET_ADMIN))
1228		return -EPERM;
1229	if (copy_from_user(&ip6rd, data, sizeof(ip6rd)))
1230		return -EFAULT;
1231
1232	if (cmd != SIOCDEL6RD) {
1233		err = ipip6_tunnel_update_6rd(t, &ip6rd);
1234		if (err < 0)
1235			return err;
1236	} else
1237		ipip6_tunnel_clone_6rd(dev, dev_to_sit_net(dev));
1238	return 0;
1239}
1240
1241#endif /* CONFIG_IPV6_SIT_6RD */
1242
1243static bool ipip6_valid_ip_proto(u8 ipproto)
1244{
1245	return ipproto == IPPROTO_IPV6 ||
1246		ipproto == IPPROTO_IPIP ||
1247#if IS_ENABLED(CONFIG_MPLS)
1248		ipproto == IPPROTO_MPLS ||
1249#endif
1250		ipproto == 0;
1251}
1252
1253static int
1254__ipip6_tunnel_ioctl_validate(struct net *net, struct ip_tunnel_parm *p)
1255{
1256	if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1257		return -EPERM;
1258
1259	if (!ipip6_valid_ip_proto(p->iph.protocol))
1260		return -EINVAL;
1261	if (p->iph.version != 4 ||
1262	    p->iph.ihl != 5 || (p->iph.frag_off & htons(~IP_DF)))
1263		return -EINVAL;
1264
1265	if (p->iph.ttl)
1266		p->iph.frag_off |= htons(IP_DF);
1267	return 0;
1268}
1269
1270static int
1271ipip6_tunnel_get(struct net_device *dev, struct ip_tunnel_parm *p)
1272{
1273	struct ip_tunnel *t = netdev_priv(dev);
1274
1275	if (dev == dev_to_sit_net(dev)->fb_tunnel_dev)
1276		t = ipip6_tunnel_locate(t->net, p, 0);
1277	if (!t)
1278		t = netdev_priv(dev);
1279	memcpy(p, &t->parms, sizeof(*p));
1280	return 0;
1281}
1282
1283static int
1284ipip6_tunnel_add(struct net_device *dev, struct ip_tunnel_parm *p)
1285{
1286	struct ip_tunnel *t = netdev_priv(dev);
1287	int err;
1288
1289	err = __ipip6_tunnel_ioctl_validate(t->net, p);
1290	if (err)
1291		return err;
1292
1293	t = ipip6_tunnel_locate(t->net, p, 1);
1294	if (!t)
1295		return -ENOBUFS;
1296	return 0;
1297}
1298
1299static int
1300ipip6_tunnel_change(struct net_device *dev, struct ip_tunnel_parm *p)
1301{
1302	struct ip_tunnel *t = netdev_priv(dev);
1303	int err;
1304
1305	err = __ipip6_tunnel_ioctl_validate(t->net, p);
1306	if (err)
1307		return err;
1308
1309	t = ipip6_tunnel_locate(t->net, p, 0);
1310	if (dev == dev_to_sit_net(dev)->fb_tunnel_dev) {
1311		if (!t)
1312			return -ENOENT;
1313	} else {
1314		if (t) {
1315			if (t->dev != dev)
1316				return -EEXIST;
1317		} else {
1318			if (((dev->flags & IFF_POINTOPOINT) && !p->iph.daddr) ||
1319			    (!(dev->flags & IFF_POINTOPOINT) && p->iph.daddr))
1320				return -EINVAL;
1321			t = netdev_priv(dev);
1322		}
1323
1324		ipip6_tunnel_update(t, p, t->fwmark);
1325	}
1326
1327	return 0;
1328}
1329
1330static int
1331ipip6_tunnel_del(struct net_device *dev, struct ip_tunnel_parm *p)
1332{
1333	struct ip_tunnel *t = netdev_priv(dev);
1334
1335	if (!ns_capable(t->net->user_ns, CAP_NET_ADMIN))
1336		return -EPERM;
1337
1338	if (dev == dev_to_sit_net(dev)->fb_tunnel_dev) {
1339		t = ipip6_tunnel_locate(t->net, p, 0);
1340		if (!t)
1341			return -ENOENT;
1342		if (t == netdev_priv(dev_to_sit_net(dev)->fb_tunnel_dev))
1343			return -EPERM;
1344		dev = t->dev;
1345	}
1346	unregister_netdevice(dev);
1347	return 0;
1348}
1349
1350static int
1351ipip6_tunnel_ctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd)
1352{
1353	switch (cmd) {
1354	case SIOCGETTUNNEL:
1355		return ipip6_tunnel_get(dev, p);
1356	case SIOCADDTUNNEL:
1357		return ipip6_tunnel_add(dev, p);
1358	case SIOCCHGTUNNEL:
1359		return ipip6_tunnel_change(dev, p);
1360	case SIOCDELTUNNEL:
1361		return ipip6_tunnel_del(dev, p);
1362	default:
1363		return -EINVAL;
1364	}
1365}
1366
1367static int
1368ipip6_tunnel_siocdevprivate(struct net_device *dev, struct ifreq *ifr,
1369			    void __user *data, int cmd)
1370{
1371	switch (cmd) {
1372	case SIOCGETTUNNEL:
1373	case SIOCADDTUNNEL:
1374	case SIOCCHGTUNNEL:
1375	case SIOCDELTUNNEL:
1376		return ip_tunnel_siocdevprivate(dev, ifr, data, cmd);
1377	case SIOCGETPRL:
1378		return ipip6_tunnel_get_prl(dev, data);
1379	case SIOCADDPRL:
1380	case SIOCDELPRL:
1381	case SIOCCHGPRL:
1382		return ipip6_tunnel_prl_ctl(dev, data, cmd);
1383#ifdef CONFIG_IPV6_SIT_6RD
1384	case SIOCGET6RD:
1385		return ipip6_tunnel_get6rd(dev, data);
1386	case SIOCADD6RD:
1387	case SIOCCHG6RD:
1388	case SIOCDEL6RD:
1389		return ipip6_tunnel_6rdctl(dev, data, cmd);
1390#endif
1391	default:
1392		return -EINVAL;
1393	}
1394}
1395
1396static const struct net_device_ops ipip6_netdev_ops = {
1397	.ndo_init	= ipip6_tunnel_init,
1398	.ndo_uninit	= ipip6_tunnel_uninit,
1399	.ndo_start_xmit	= sit_tunnel_xmit,
1400	.ndo_siocdevprivate = ipip6_tunnel_siocdevprivate,
1401	.ndo_get_stats64 = dev_get_tstats64,
1402	.ndo_get_iflink = ip_tunnel_get_iflink,
1403	.ndo_tunnel_ctl = ipip6_tunnel_ctl,
1404};
1405
1406static void ipip6_dev_free(struct net_device *dev)
1407{
1408	struct ip_tunnel *tunnel = netdev_priv(dev);
1409
1410	dst_cache_destroy(&tunnel->dst_cache);
1411	free_percpu(dev->tstats);
1412}
1413
1414#define SIT_FEATURES (NETIF_F_SG	   | \
1415		      NETIF_F_FRAGLIST	   | \
1416		      NETIF_F_HIGHDMA	   | \
1417		      NETIF_F_GSO_SOFTWARE | \
1418		      NETIF_F_HW_CSUM)
1419
1420static void ipip6_tunnel_setup(struct net_device *dev)
1421{
1422	struct ip_tunnel *tunnel = netdev_priv(dev);
1423	int t_hlen = tunnel->hlen + sizeof(struct iphdr);
1424
1425	dev->netdev_ops		= &ipip6_netdev_ops;
1426	dev->header_ops		= &ip_tunnel_header_ops;
1427	dev->needs_free_netdev	= true;
1428	dev->priv_destructor	= ipip6_dev_free;
1429
1430	dev->type		= ARPHRD_SIT;
1431	dev->mtu		= ETH_DATA_LEN - t_hlen;
1432	dev->min_mtu		= IPV6_MIN_MTU;
1433	dev->max_mtu		= IP6_MAX_MTU - t_hlen;
1434	dev->flags		= IFF_NOARP;
1435	netif_keep_dst(dev);
1436	dev->addr_len		= 4;
1437	dev->features		|= NETIF_F_LLTX;
1438	dev->features		|= SIT_FEATURES;
1439	dev->hw_features	|= SIT_FEATURES;
1440}
1441
1442static int ipip6_tunnel_init(struct net_device *dev)
1443{
1444	struct ip_tunnel *tunnel = netdev_priv(dev);
1445	int err;
1446
1447	tunnel->dev = dev;
1448	tunnel->net = dev_net(dev);
1449	strcpy(tunnel->parms.name, dev->name);
1450
1451	ipip6_tunnel_bind_dev(dev);
1452	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1453	if (!dev->tstats)
1454		return -ENOMEM;
1455
1456	err = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL);
1457	if (err) {
1458		free_percpu(dev->tstats);
1459		dev->tstats = NULL;
1460		return err;
1461	}
1462	netdev_hold(dev, &tunnel->dev_tracker, GFP_KERNEL);
1463	return 0;
1464}
1465
1466static void __net_init ipip6_fb_tunnel_init(struct net_device *dev)
1467{
1468	struct ip_tunnel *tunnel = netdev_priv(dev);
1469	struct iphdr *iph = &tunnel->parms.iph;
1470	struct net *net = dev_net(dev);
1471	struct sit_net *sitn = net_generic(net, sit_net_id);
1472
1473	iph->version		= 4;
1474	iph->protocol		= IPPROTO_IPV6;
1475	iph->ihl		= 5;
1476	iph->ttl		= 64;
1477
1478	rcu_assign_pointer(sitn->tunnels_wc[0], tunnel);
1479}
1480
1481static int ipip6_validate(struct nlattr *tb[], struct nlattr *data[],
1482			  struct netlink_ext_ack *extack)
1483{
1484	u8 proto;
1485
1486	if (!data || !data[IFLA_IPTUN_PROTO])
1487		return 0;
1488
1489	proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1490	if (!ipip6_valid_ip_proto(proto))
1491		return -EINVAL;
1492
1493	return 0;
1494}
1495
1496static void ipip6_netlink_parms(struct nlattr *data[],
1497				struct ip_tunnel_parm *parms,
1498				__u32 *fwmark)
1499{
1500	memset(parms, 0, sizeof(*parms));
1501
1502	parms->iph.version = 4;
1503	parms->iph.protocol = IPPROTO_IPV6;
1504	parms->iph.ihl = 5;
1505	parms->iph.ttl = 64;
1506
1507	if (!data)
1508		return;
1509
1510	ip_tunnel_netlink_parms(data, parms);
1511
1512	if (data[IFLA_IPTUN_FWMARK])
1513		*fwmark = nla_get_u32(data[IFLA_IPTUN_FWMARK]);
1514}
1515
1516#ifdef CONFIG_IPV6_SIT_6RD
1517/* This function returns true when 6RD attributes are present in the nl msg */
1518static bool ipip6_netlink_6rd_parms(struct nlattr *data[],
1519				    struct ip_tunnel_6rd *ip6rd)
1520{
1521	bool ret = false;
1522	memset(ip6rd, 0, sizeof(*ip6rd));
1523
1524	if (!data)
1525		return ret;
1526
1527	if (data[IFLA_IPTUN_6RD_PREFIX]) {
1528		ret = true;
1529		ip6rd->prefix = nla_get_in6_addr(data[IFLA_IPTUN_6RD_PREFIX]);
1530	}
1531
1532	if (data[IFLA_IPTUN_6RD_RELAY_PREFIX]) {
1533		ret = true;
1534		ip6rd->relay_prefix =
1535			nla_get_be32(data[IFLA_IPTUN_6RD_RELAY_PREFIX]);
1536	}
1537
1538	if (data[IFLA_IPTUN_6RD_PREFIXLEN]) {
1539		ret = true;
1540		ip6rd->prefixlen = nla_get_u16(data[IFLA_IPTUN_6RD_PREFIXLEN]);
1541	}
1542
1543	if (data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]) {
1544		ret = true;
1545		ip6rd->relay_prefixlen =
1546			nla_get_u16(data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]);
1547	}
1548
1549	return ret;
1550}
1551#endif
1552
1553static int ipip6_newlink(struct net *src_net, struct net_device *dev,
1554			 struct nlattr *tb[], struct nlattr *data[],
1555			 struct netlink_ext_ack *extack)
1556{
1557	struct net *net = dev_net(dev);
1558	struct ip_tunnel *nt;
1559	struct ip_tunnel_encap ipencap;
1560#ifdef CONFIG_IPV6_SIT_6RD
1561	struct ip_tunnel_6rd ip6rd;
1562#endif
1563	int err;
1564
1565	nt = netdev_priv(dev);
1566
1567	if (ip_tunnel_netlink_encap_parms(data, &ipencap)) {
1568		err = ip_tunnel_encap_setup(nt, &ipencap);
1569		if (err < 0)
1570			return err;
1571	}
1572
1573	ipip6_netlink_parms(data, &nt->parms, &nt->fwmark);
1574
1575	if (ipip6_tunnel_locate(net, &nt->parms, 0))
1576		return -EEXIST;
1577
1578	err = ipip6_tunnel_create(dev);
1579	if (err < 0)
1580		return err;
1581
1582	if (tb[IFLA_MTU]) {
1583		u32 mtu = nla_get_u32(tb[IFLA_MTU]);
1584
1585		if (mtu >= IPV6_MIN_MTU &&
1586		    mtu <= IP6_MAX_MTU - dev->hard_header_len)
1587			dev->mtu = mtu;
1588	}
1589
1590#ifdef CONFIG_IPV6_SIT_6RD
1591	if (ipip6_netlink_6rd_parms(data, &ip6rd)) {
1592		err = ipip6_tunnel_update_6rd(nt, &ip6rd);
1593		if (err < 0)
1594			unregister_netdevice_queue(dev, NULL);
1595	}
1596#endif
1597
1598	return err;
1599}
1600
1601static int ipip6_changelink(struct net_device *dev, struct nlattr *tb[],
1602			    struct nlattr *data[],
1603			    struct netlink_ext_ack *extack)
1604{
1605	struct ip_tunnel *t = netdev_priv(dev);
1606	struct ip_tunnel_parm p;
1607	struct ip_tunnel_encap ipencap;
1608	struct net *net = t->net;
1609	struct sit_net *sitn = net_generic(net, sit_net_id);
1610#ifdef CONFIG_IPV6_SIT_6RD
1611	struct ip_tunnel_6rd ip6rd;
1612#endif
1613	__u32 fwmark = t->fwmark;
1614	int err;
1615
1616	if (dev == sitn->fb_tunnel_dev)
1617		return -EINVAL;
1618
1619	if (ip_tunnel_netlink_encap_parms(data, &ipencap)) {
1620		err = ip_tunnel_encap_setup(t, &ipencap);
1621		if (err < 0)
1622			return err;
1623	}
1624
1625	ipip6_netlink_parms(data, &p, &fwmark);
1626
1627	if (((dev->flags & IFF_POINTOPOINT) && !p.iph.daddr) ||
1628	    (!(dev->flags & IFF_POINTOPOINT) && p.iph.daddr))
1629		return -EINVAL;
1630
1631	t = ipip6_tunnel_locate(net, &p, 0);
1632
1633	if (t) {
1634		if (t->dev != dev)
1635			return -EEXIST;
1636	} else
1637		t = netdev_priv(dev);
1638
1639	ipip6_tunnel_update(t, &p, fwmark);
1640
1641#ifdef CONFIG_IPV6_SIT_6RD
1642	if (ipip6_netlink_6rd_parms(data, &ip6rd))
1643		return ipip6_tunnel_update_6rd(t, &ip6rd);
1644#endif
1645
1646	return 0;
1647}
1648
1649static size_t ipip6_get_size(const struct net_device *dev)
1650{
1651	return
1652		/* IFLA_IPTUN_LINK */
1653		nla_total_size(4) +
1654		/* IFLA_IPTUN_LOCAL */
1655		nla_total_size(4) +
1656		/* IFLA_IPTUN_REMOTE */
1657		nla_total_size(4) +
1658		/* IFLA_IPTUN_TTL */
1659		nla_total_size(1) +
1660		/* IFLA_IPTUN_TOS */
1661		nla_total_size(1) +
1662		/* IFLA_IPTUN_PMTUDISC */
1663		nla_total_size(1) +
1664		/* IFLA_IPTUN_FLAGS */
1665		nla_total_size(2) +
1666		/* IFLA_IPTUN_PROTO */
1667		nla_total_size(1) +
1668#ifdef CONFIG_IPV6_SIT_6RD
1669		/* IFLA_IPTUN_6RD_PREFIX */
1670		nla_total_size(sizeof(struct in6_addr)) +
1671		/* IFLA_IPTUN_6RD_RELAY_PREFIX */
1672		nla_total_size(4) +
1673		/* IFLA_IPTUN_6RD_PREFIXLEN */
1674		nla_total_size(2) +
1675		/* IFLA_IPTUN_6RD_RELAY_PREFIXLEN */
1676		nla_total_size(2) +
1677#endif
1678		/* IFLA_IPTUN_ENCAP_TYPE */
1679		nla_total_size(2) +
1680		/* IFLA_IPTUN_ENCAP_FLAGS */
1681		nla_total_size(2) +
1682		/* IFLA_IPTUN_ENCAP_SPORT */
1683		nla_total_size(2) +
1684		/* IFLA_IPTUN_ENCAP_DPORT */
1685		nla_total_size(2) +
1686		/* IFLA_IPTUN_FWMARK */
1687		nla_total_size(4) +
1688		0;
1689}
1690
1691static int ipip6_fill_info(struct sk_buff *skb, const struct net_device *dev)
1692{
1693	struct ip_tunnel *tunnel = netdev_priv(dev);
1694	struct ip_tunnel_parm *parm = &tunnel->parms;
1695
1696	if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
1697	    nla_put_in_addr(skb, IFLA_IPTUN_LOCAL, parm->iph.saddr) ||
1698	    nla_put_in_addr(skb, IFLA_IPTUN_REMOTE, parm->iph.daddr) ||
1699	    nla_put_u8(skb, IFLA_IPTUN_TTL, parm->iph.ttl) ||
1700	    nla_put_u8(skb, IFLA_IPTUN_TOS, parm->iph.tos) ||
1701	    nla_put_u8(skb, IFLA_IPTUN_PMTUDISC,
1702		       !!(parm->iph.frag_off & htons(IP_DF))) ||
1703	    nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->iph.protocol) ||
1704	    nla_put_be16(skb, IFLA_IPTUN_FLAGS, parm->i_flags) ||
1705	    nla_put_u32(skb, IFLA_IPTUN_FWMARK, tunnel->fwmark))
1706		goto nla_put_failure;
1707
1708#ifdef CONFIG_IPV6_SIT_6RD
1709	if (nla_put_in6_addr(skb, IFLA_IPTUN_6RD_PREFIX,
1710			     &tunnel->ip6rd.prefix) ||
1711	    nla_put_in_addr(skb, IFLA_IPTUN_6RD_RELAY_PREFIX,
1712			    tunnel->ip6rd.relay_prefix) ||
1713	    nla_put_u16(skb, IFLA_IPTUN_6RD_PREFIXLEN,
1714			tunnel->ip6rd.prefixlen) ||
1715	    nla_put_u16(skb, IFLA_IPTUN_6RD_RELAY_PREFIXLEN,
1716			tunnel->ip6rd.relay_prefixlen))
1717		goto nla_put_failure;
1718#endif
1719
1720	if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE,
1721			tunnel->encap.type) ||
1722	    nla_put_be16(skb, IFLA_IPTUN_ENCAP_SPORT,
1723			tunnel->encap.sport) ||
1724	    nla_put_be16(skb, IFLA_IPTUN_ENCAP_DPORT,
1725			tunnel->encap.dport) ||
1726	    nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS,
1727			tunnel->encap.flags))
1728		goto nla_put_failure;
1729
1730	return 0;
1731
1732nla_put_failure:
1733	return -EMSGSIZE;
1734}
1735
1736static const struct nla_policy ipip6_policy[IFLA_IPTUN_MAX + 1] = {
1737	[IFLA_IPTUN_LINK]		= { .type = NLA_U32 },
1738	[IFLA_IPTUN_LOCAL]		= { .type = NLA_U32 },
1739	[IFLA_IPTUN_REMOTE]		= { .type = NLA_U32 },
1740	[IFLA_IPTUN_TTL]		= { .type = NLA_U8 },
1741	[IFLA_IPTUN_TOS]		= { .type = NLA_U8 },
1742	[IFLA_IPTUN_PMTUDISC]		= { .type = NLA_U8 },
1743	[IFLA_IPTUN_FLAGS]		= { .type = NLA_U16 },
1744	[IFLA_IPTUN_PROTO]		= { .type = NLA_U8 },
1745#ifdef CONFIG_IPV6_SIT_6RD
1746	[IFLA_IPTUN_6RD_PREFIX]		= { .len = sizeof(struct in6_addr) },
1747	[IFLA_IPTUN_6RD_RELAY_PREFIX]	= { .type = NLA_U32 },
1748	[IFLA_IPTUN_6RD_PREFIXLEN]	= { .type = NLA_U16 },
1749	[IFLA_IPTUN_6RD_RELAY_PREFIXLEN] = { .type = NLA_U16 },
1750#endif
1751	[IFLA_IPTUN_ENCAP_TYPE]		= { .type = NLA_U16 },
1752	[IFLA_IPTUN_ENCAP_FLAGS]	= { .type = NLA_U16 },
1753	[IFLA_IPTUN_ENCAP_SPORT]	= { .type = NLA_U16 },
1754	[IFLA_IPTUN_ENCAP_DPORT]	= { .type = NLA_U16 },
1755	[IFLA_IPTUN_FWMARK]		= { .type = NLA_U32 },
1756};
1757
1758static void ipip6_dellink(struct net_device *dev, struct list_head *head)
1759{
1760	struct net *net = dev_net(dev);
1761	struct sit_net *sitn = net_generic(net, sit_net_id);
1762
1763	if (dev != sitn->fb_tunnel_dev)
1764		unregister_netdevice_queue(dev, head);
1765}
1766
1767static struct rtnl_link_ops sit_link_ops __read_mostly = {
1768	.kind		= "sit",
1769	.maxtype	= IFLA_IPTUN_MAX,
1770	.policy		= ipip6_policy,
1771	.priv_size	= sizeof(struct ip_tunnel),
1772	.setup		= ipip6_tunnel_setup,
1773	.validate	= ipip6_validate,
1774	.newlink	= ipip6_newlink,
1775	.changelink	= ipip6_changelink,
1776	.get_size	= ipip6_get_size,
1777	.fill_info	= ipip6_fill_info,
1778	.dellink	= ipip6_dellink,
1779	.get_link_net	= ip_tunnel_get_link_net,
1780};
1781
1782static struct xfrm_tunnel sit_handler __read_mostly = {
1783	.handler	=	ipip6_rcv,
1784	.err_handler	=	ipip6_err,
1785	.priority	=	1,
1786};
1787
1788static struct xfrm_tunnel ipip_handler __read_mostly = {
1789	.handler	=	ipip_rcv,
1790	.err_handler	=	ipip6_err,
1791	.priority	=	2,
1792};
1793
1794#if IS_ENABLED(CONFIG_MPLS)
1795static struct xfrm_tunnel mplsip_handler __read_mostly = {
1796	.handler	=	mplsip_rcv,
1797	.err_handler	=	ipip6_err,
1798	.priority	=	2,
1799};
1800#endif
1801
1802static void __net_exit sit_destroy_tunnels(struct net *net,
1803					   struct list_head *head)
1804{
1805	struct sit_net *sitn = net_generic(net, sit_net_id);
1806	struct net_device *dev, *aux;
1807	int prio;
1808
1809	for_each_netdev_safe(net, dev, aux)
1810		if (dev->rtnl_link_ops == &sit_link_ops)
1811			unregister_netdevice_queue(dev, head);
1812
1813	for (prio = 0; prio < 4; prio++) {
1814		int h;
1815		for (h = 0; h < (prio ? IP6_SIT_HASH_SIZE : 1); h++) {
1816			struct ip_tunnel *t;
1817
1818			t = rtnl_dereference(sitn->tunnels[prio][h]);
1819			while (t) {
1820				/* If dev is in the same netns, it has already
1821				 * been added to the list by the previous loop.
1822				 */
1823				if (!net_eq(dev_net(t->dev), net))
1824					unregister_netdevice_queue(t->dev,
1825								   head);
1826				t = rtnl_dereference(t->next);
1827			}
1828		}
1829	}
1830}
1831
1832static int __net_init sit_init_net(struct net *net)
1833{
1834	struct sit_net *sitn = net_generic(net, sit_net_id);
1835	struct ip_tunnel *t;
1836	int err;
1837
1838	sitn->tunnels[0] = sitn->tunnels_wc;
1839	sitn->tunnels[1] = sitn->tunnels_l;
1840	sitn->tunnels[2] = sitn->tunnels_r;
1841	sitn->tunnels[3] = sitn->tunnels_r_l;
1842
1843	if (!net_has_fallback_tunnels(net))
1844		return 0;
1845
1846	sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0",
1847					   NET_NAME_UNKNOWN,
1848					   ipip6_tunnel_setup);
1849	if (!sitn->fb_tunnel_dev) {
1850		err = -ENOMEM;
1851		goto err_alloc_dev;
1852	}
1853	dev_net_set(sitn->fb_tunnel_dev, net);
1854	sitn->fb_tunnel_dev->rtnl_link_ops = &sit_link_ops;
1855	/* FB netdevice is special: we have one, and only one per netns.
1856	 * Allowing to move it to another netns is clearly unsafe.
1857	 */
1858	sitn->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
1859
1860	err = register_netdev(sitn->fb_tunnel_dev);
1861	if (err)
1862		goto err_reg_dev;
1863
1864	ipip6_tunnel_clone_6rd(sitn->fb_tunnel_dev, sitn);
1865	ipip6_fb_tunnel_init(sitn->fb_tunnel_dev);
1866
1867	t = netdev_priv(sitn->fb_tunnel_dev);
1868
1869	strcpy(t->parms.name, sitn->fb_tunnel_dev->name);
1870	return 0;
1871
1872err_reg_dev:
1873	free_netdev(sitn->fb_tunnel_dev);
1874err_alloc_dev:
1875	return err;
1876}
1877
1878static void __net_exit sit_exit_batch_net(struct list_head *net_list)
1879{
1880	LIST_HEAD(list);
1881	struct net *net;
1882
1883	rtnl_lock();
1884	list_for_each_entry(net, net_list, exit_list)
1885		sit_destroy_tunnels(net, &list);
1886
1887	unregister_netdevice_many(&list);
1888	rtnl_unlock();
1889}
1890
1891static struct pernet_operations sit_net_ops = {
1892	.init = sit_init_net,
1893	.exit_batch = sit_exit_batch_net,
1894	.id   = &sit_net_id,
1895	.size = sizeof(struct sit_net),
1896};
1897
1898static void __exit sit_cleanup(void)
1899{
1900	rtnl_link_unregister(&sit_link_ops);
1901	xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1902	xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
1903#if IS_ENABLED(CONFIG_MPLS)
1904	xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS);
1905#endif
1906
1907	unregister_pernet_device(&sit_net_ops);
1908	rcu_barrier(); /* Wait for completion of call_rcu()'s */
1909}
1910
1911static int __init sit_init(void)
1912{
1913	int err;
1914
1915	pr_info("IPv6, IPv4 and MPLS over IPv4 tunneling driver\n");
1916
1917	err = register_pernet_device(&sit_net_ops);
1918	if (err < 0)
1919		return err;
1920	err = xfrm4_tunnel_register(&sit_handler, AF_INET6);
1921	if (err < 0) {
1922		pr_info("%s: can't register ip6ip4\n", __func__);
1923		goto xfrm_tunnel_failed;
1924	}
1925	err = xfrm4_tunnel_register(&ipip_handler, AF_INET);
1926	if (err < 0) {
1927		pr_info("%s: can't register ip4ip4\n", __func__);
1928		goto xfrm_tunnel4_failed;
1929	}
1930#if IS_ENABLED(CONFIG_MPLS)
1931	err = xfrm4_tunnel_register(&mplsip_handler, AF_MPLS);
1932	if (err < 0) {
1933		pr_info("%s: can't register mplsip\n", __func__);
1934		goto xfrm_tunnel_mpls_failed;
1935	}
1936#endif
1937	err = rtnl_link_register(&sit_link_ops);
1938	if (err < 0)
1939		goto rtnl_link_failed;
1940
1941out:
1942	return err;
1943
1944rtnl_link_failed:
1945#if IS_ENABLED(CONFIG_MPLS)
1946	xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS);
1947xfrm_tunnel_mpls_failed:
1948#endif
1949	xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
1950xfrm_tunnel4_failed:
1951	xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1952xfrm_tunnel_failed:
1953	unregister_pernet_device(&sit_net_ops);
1954	goto out;
1955}
1956
1957module_init(sit_init);
1958module_exit(sit_cleanup);
1959MODULE_LICENSE("GPL");
1960MODULE_ALIAS_RTNL_LINK("sit");
1961MODULE_ALIAS_NETDEV("sit0");
1962