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
64	static bool log_ecn_error = true;
65	module_param(log_ecn_error, bool, 0644);
66	MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
67
68	static int ipip6_tunnel_init(struct net_device *dev);
69	static void ipip6_tunnel_setup(struct net_device *dev);
70	static void ipip6_dev_free(struct net_device *dev);
71	static bool check_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst,
72	__be32 *v4dst);
73	static struct rtnl_link_ops sit_link_ops __read_mostly;
74
75	static unsigned int sit_net_id __read_mostly;
76	struct 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
86	static 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(net: t->net, id: sit_net_id);
91	}
92
93	/*
94	* Must be invoked with rcu_read_lock
95	*/
96	static 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, id: 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
135	static 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
154	static inline struct ip_tunnel __rcu **ipip6_bucket(struct sit_net *sitn,
155	struct ip_tunnel *t)
156	{
157	return __ipip6_bucket(sitn, parms: &t->parms);
158	}
159
160	static 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
175	static 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
183	static 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(addr: &t->ip6rd.prefix, htonl(0x20020000), w2: 0, w3: 0, w4: 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(dev: sitn->fb_tunnel_dev);
195	memcpy(&t->ip6rd, &t0->ip6rd, sizeof(t->ip6rd));
196	}
197	#endif
198	}
199
200	static 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, id: sit_net_id);
205	int err;
206
207	__dev_addr_set(dev, addr: &t->parms.iph.saddr, len: 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
224	out:
225	return err;
226	}
227
228	static 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, id: 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(name: parms->name))
256	goto failed;
257	strscpy(p: name, q: parms->name, IFNAMSIZ);
258	} else {
259	strcpy(p: name, q: "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(p: parms->name, q: dev->name);
276
277	return nt;
278
279	failed_free:
280	free_netdev(dev);
281	failed:
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
290	static 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
302	static 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(to: &kprl, from: a, n: 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(n: cmax, size: 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(n: ca, size: 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(to: a + 1, from: kp, n: len)) || put_user(len, &a->datalen))
360	ret = -EFAULT;
361
362	kfree(objp: kp);
363	out:
364	return ret;
365	}
366
367	static int
368	ipip6_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(size: 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);
405	out:
406	return err;
407	}
408
409	static 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(objp: p);
417	p = n;
418	} while (p);
419	}
420
421	static int
422	ipip6_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(head: &x->rcu_head, func: prl_list_destroy_rcu);
447	t->prl = NULL;
448	}
449	}
450	out:
451	return err;
452	}
453
454	static 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(ns: 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(to: &prl, from: data, n: sizeof(prl)))
467	return -EFAULT;
468
469	switch (cmd) {
470	case SIOCDELPRL:
471	err = ipip6_tunnel_del_prl(t, a: &prl);
472	break;
473	case SIOCADDPRL:
474	case SIOCCHGPRL:
475	err = ipip6_tunnel_add_prl(t, a: &prl, chg: cmd == SIOCCHGPRL);
476	break;
477	}
478	dst_cache_reset(dst_cache: &t->dst_cache);
479	netdev_state_change(dev);
480	return err;
481	}
482
483	static int
484	isatap_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, addr: 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(addr: addr6) &&
500	(addr6->s6_addr32[3] == iph->saddr) &&
501	ipv6_chk_prefix(addr: addr6, dev: t->dev))
502	skb->ndisc_nodetype = NDISC_NODETYPE_HOST;
503	else
504	ok = 0;
505	}
506	rcu_read_unlock();
507	return ok;
508	}
509
510	static void ipip6_tunnel_uninit(struct net_device *dev)
511	{
512	struct ip_tunnel *tunnel = netdev_priv(dev);
513	struct sit_net *sitn = net_generic(net: tunnel->net, id: 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, t: tunnel);
519	ipip6_tunnel_del_prl(t: tunnel, NULL);
520	}
521	dst_cache_reset(dst_cache: &tunnel->dst_cache);
522	netdev_put(dev, tracker: &tunnel->dev_tracker);
523	}
524
525	static 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(dev: skb->dev) ? IPCB(skb)->iif : 0;
565	t = ipip6_tunnel_lookup(net: dev_net(dev: skb->dev), dev: skb->dev,
566	remote: iph->daddr, local: 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, net: dev_net(dev: skb->dev), mtu: info,
572	oif: t->parms.link, protocol: iph->protocol);
573	err = 0;
574	goto out;
575	}
576	if (type == ICMP_REDIRECT) {
577	ipv4_redirect(skb, net: dev_net(dev: skb->dev), oif: t->parms.link,
578	protocol: iph->protocol);
579	err = 0;
580	goto out;
581	}
582
583	err = 0;
584	if (__in6_dev_get(dev: skb->dev) &&
585	!ip6_err_gen_icmpv6_unreach(skb, nhs: 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;
599	out:
600	return err;
601	}
602
603	static 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, v6dst: v6addr, v4dst: &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	*/
624	static 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(addr: v6dst, prefix_len, dev: tunnel->dev);
636	}
637
638	/* Returns true if a packet is spoofed */
639	static 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, t: 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, v6dst: &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
676	static 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(dev: skb->dev) ? IPCB(skb)->iif : 0;
684	tunnel = ipip6_tunnel_lookup(net: dev_net(dev: skb->dev), dev: skb->dev,
685	remote: iph->saddr, local: 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, hdr_len: 0, htons(ETH_P_IPV6),
702	xnet: !net_eq(net1: tunnel->net, net2: dev_net(dev: 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(oiph: 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(dev: tunnel->dev, len: 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;
732	out:
733	kfree_skb(skb);
734	return 0;
735	}
736
737	static 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)
743	static 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
749	static 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(dev: skb->dev) ? IPCB(skb)->iif : 0;
756
757	iph = ip_hdr(skb);
758	tunnel = ipip6_tunnel_lookup(net: dev_net(dev: skb->dev), dev: skb->dev,
759	remote: iph->saddr, local: 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, dir: 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, hdr_len: 0, inner_proto: tpi->proto, xnet: 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
784	drop:
785	kfree_skb(skb);
786	return 0;
787	}
788
789	static int ipip_rcv(struct sk_buff *skb)
790	{
791	return sit_tunnel_rcv(skb, IPPROTO_IPIP);
792	}
793
794	#if IS_ENABLED(CONFIG_MPLS)
795	static 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	*/
805	static 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(addr1: v6dst, addr2: &tunnel->ip6rd.prefix,
810	prefixlen: 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
840	static inline __be32 try_6rd(struct ip_tunnel *tunnel,
841	const struct in6_addr *v6dst)
842	{
843	__be32 dst = 0;
844	check_6rd(tunnel, v6dst, v4dst: &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
853	static 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(ipv6h: 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(dst: skb_dst(skb), daddr: &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(addr: addr6);
891
892	if ((addr_type & IPV6_ADDR_UNICAST) &&
893	ipv6_addr_is_isatap(addr: 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, v6dst: &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(dst: skb_dst(skb), daddr: &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(addr: addr6);
920
921	if (addr_type == IPV6_ADDR_ANY) {
922	addr6 = &ipv6_hdr(skb)->daddr;
923	addr_type = ipv6_addr_type(addr: 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: &fl4, oif: tunnel->parms.link, mark: tunnel->fwmark,
937	RT_TOS(tos), scope: RT_SCOPE_UNIVERSE, IPPROTO_IPV6,
938	flags: 0, daddr: dst, saddr: tiph->saddr, dport: 0, sport: 0,
939	uid: sock_net_uid(net: tunnel->net, NULL));
940
941	rt = dst_cache_get_ip4(dst_cache: &tunnel->dst_cache, saddr: &fl4.saddr);
942	if (!rt) {
943	rt = ip_route_output_flow(tunnel->net, flp: &fl4, NULL);
944	if (IS_ERR(ptr: rt)) {
945	DEV_STATS_INC(dev, tx_carrier_errors);
946	goto tx_error_icmp;
947	}
948	dst_cache_set_ip4(dst_cache: &tunnel->dst_cache, dst: &rt->dst, saddr: 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, gso_type_mask: SKB_GSO_IPXIP4)) {
965	ip_rt_put(rt);
966	goto tx_error;
967	}
968
969	if (df) {
970	mtu = dst_mtu(dst: &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_in: skb, ICMPV6_PKT_TOOBIG, code: 0, info: 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, len: 0))) {
1009	struct sk_buff *new_skb = skb_realloc_headroom(skb, headroom: 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(skb: new_skb, sk: 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(outer: tos, inner: ipv6_get_dsfield(ipv6h: iph6));
1026
1027	if (ip_tunnel_encap(skb, e: &tunnel->encap, protocol: &protocol, fl4: &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, src: fl4.saddr, dst: fl4.daddr, proto: protocol, tos, ttl,
1035	df, xnet: !net_eq(net1: tunnel->net, net2: dev_net(dev)));
1036	return NETDEV_TX_OK;
1037
1038	tx_error_icmp:
1039	dst_link_failure(skb);
1040	tx_error:
1041	kfree_skb(skb);
1042	DEV_STATS_INC(dev, tx_errors);
1043	return NETDEV_TX_OK;
1044	}
1045
1046	static 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, gso_type_mask: SKB_GSO_IPXIP4))
1053	goto tx_error;
1054
1055	skb_set_inner_ipproto(skb, ipproto);
1056
1057	ip_tunnel_xmit(skb, dev, tnl_params: tiph, protocol: ipproto);
1058	return NETDEV_TX_OK;
1059	tx_error:
1060	kfree_skb(skb);
1061	DEV_STATS_INC(dev, tx_errors);
1062	return NETDEV_TX_OK;
1063	}
1064
1065	static 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
1089	tx_err:
1090	DEV_STATS_INC(dev, tx_errors);
1091	kfree_skb(skb);
1092	return NETDEV_TX_OK;
1093
1094	}
1095
1096	static 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(net: tunnel->net, fl4: &fl4,
1109	NULL,
1110	daddr: iph->daddr, saddr: iph->saddr,
1111	dport: 0, sport: 0,
1112	IPPROTO_IPV6,
1113	RT_TOS(iph->tos),
1114	oif: tunnel->parms.link);
1115
1116	if (!IS_ERR(ptr: 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(net: tunnel->net, ifindex: tunnel->parms.link);
1125
1126	if (tdev && !netif_is_l3_master(dev: 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
1138	static 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, id: 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(dev: t->dev, addr: &p->iph.saddr, len: 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(dev: t->dev);
1158	}
1159	dst_cache_reset(dst_cache: &t->dst_cache);
1160	netdev_state_change(dev: t->dev);
1161	}
1162
1163	#ifdef CONFIG_IPV6_SIT_6RD
1164	static 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(pfx: &prefix, addr: &ip6rd->prefix, plen: ip6rd->prefixlen);
1175	if (!ipv6_addr_equal(a1: &prefix, a2: &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(dst_cache: &t->dst_cache);
1191	netdev_state_change(dev: t->dev);
1192	return 0;
1193	}
1194
1195	static int
1196	ipip6_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(to: &p, from: data, n: sizeof(p)))
1204	return -EFAULT;
1205	t = ipip6_tunnel_locate(net: t->net, parms: &p, create: 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(to: data, from: &ip6rd, n: sizeof(ip6rd)))
1215	return -EFAULT;
1216	return 0;
1217	}
1218
1219	static int
1220	ipip6_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(ns: t->net->user_ns, CAP_NET_ADMIN))
1228	return -EPERM;
1229	if (copy_from_user(to: &ip6rd, from: data, n: sizeof(ip6rd)))
1230	return -EFAULT;
1231
1232	if (cmd != SIOCDEL6RD) {
1233	err = ipip6_tunnel_update_6rd(t, ip6rd: &ip6rd);
1234	if (err < 0)
1235	return err;
1236	} else
1237	ipip6_tunnel_clone_6rd(dev, sitn: dev_to_sit_net(dev));
1238	return 0;
1239	}
1240
1241	#endif /* CONFIG_IPV6_SIT_6RD */
1242
1243	static 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
1253	static int
1254	__ipip6_tunnel_ioctl_validate(struct net *net, struct ip_tunnel_parm *p)
1255	{
1256	if (!ns_capable(ns: net->user_ns, CAP_NET_ADMIN))
1257	return -EPERM;
1258
1259	if (!ipip6_valid_ip_proto(ipproto: 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
1270	static int
1271	ipip6_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(net: t->net, parms: p, create: 0);
1277	if (!t)
1278	t = netdev_priv(dev);
1279	memcpy(p, &t->parms, sizeof(*p));
1280	return 0;
1281	}
1282
1283	static int
1284	ipip6_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(net: t->net, p);
1290	if (err)
1291	return err;
1292
1293	t = ipip6_tunnel_locate(net: t->net, parms: p, create: 1);
1294	if (!t)
1295	return -ENOBUFS;
1296	return 0;
1297	}
1298
1299	static int
1300	ipip6_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(net: t->net, p);
1306	if (err)
1307	return err;
1308
1309	t = ipip6_tunnel_locate(net: t->net, parms: p, create: 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, fwmark: t->fwmark);
1325	}
1326
1327	return 0;
1328	}
1329
1330	static int
1331	ipip6_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(ns: 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(net: t->net, parms: p, create: 0);
1340	if (!t)
1341	return -ENOENT;
1342	if (t == netdev_priv(dev: 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
1350	static int
1351	ipip6_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
1367	static int
1368	ipip6_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, a: 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
1396	static 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
1406	static void ipip6_dev_free(struct net_device *dev)
1407	{
1408	struct ip_tunnel *tunnel = netdev_priv(dev);
1409
1410	dst_cache_destroy(dst_cache: &tunnel->dst_cache);
1411	free_percpu(pdata: 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
1420	static 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
1442	static 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(p: tunnel->parms.name, q: 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(dst_cache: &tunnel->dst_cache, GFP_KERNEL);
1457	if (err) {
1458	free_percpu(pdata: dev->tstats);
1459	dev->tstats = NULL;
1460	return err;
1461	}
1462	netdev_hold(dev, tracker: &tunnel->dev_tracker, GFP_KERNEL);
1463	return 0;
1464	}
1465
1466	static 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, id: 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
1481	static 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(nla: data[IFLA_IPTUN_PROTO]);
1490	if (!ipip6_valid_ip_proto(ipproto: proto))
1491	return -EINVAL;
1492
1493	return 0;
1494	}
1495
1496	static 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(nla: 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 */
1518	static 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(nla: 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(nla: data[IFLA_IPTUN_6RD_RELAY_PREFIX]);
1536	}
1537
1538	if (data[IFLA_IPTUN_6RD_PREFIXLEN]) {
1539	ret = true;
1540	ip6rd->prefixlen = nla_get_u16(nla: 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(nla: data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]);
1547	}
1548
1549	return ret;
1550	}
1551	#endif
1552
1553	static 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, encap: &ipencap)) {
1568	err = ip_tunnel_encap_setup(t: nt, ipencap: &ipencap);
1569	if (err < 0)
1570	return err;
1571	}
1572
1573	ipip6_netlink_parms(data, parms: &nt->parms, fwmark: &nt->fwmark);
1574
1575	if (ipip6_tunnel_locate(net, parms: &nt->parms, create: 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(nla: 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: &ip6rd)) {
1592	err = ipip6_tunnel_update_6rd(t: nt, ip6rd: &ip6rd);
1593	if (err < 0)
1594	unregister_netdevice_queue(dev, NULL);
1595	}
1596	#endif
1597
1598	return err;
1599	}
1600
1601	static 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, id: 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, encap: &ipencap)) {
1620	err = ip_tunnel_encap_setup(t, ipencap: &ipencap);
1621	if (err < 0)
1622	return err;
1623	}
1624
1625	ipip6_netlink_parms(data, parms: &p, fwmark: &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, parms: &p, create: 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: &p, fwmark);
1640
1641	#ifdef CONFIG_IPV6_SIT_6RD
1642	if (ipip6_netlink_6rd_parms(data, ip6rd: &ip6rd))
1643	return ipip6_tunnel_update_6rd(t, ip6rd: &ip6rd);
1644	#endif
1645
1646	return 0;
1647	}
1648
1649	static size_t ipip6_get_size(const struct net_device *dev)
1650	{
1651	return
1652	/* IFLA_IPTUN_LINK */
1653	nla_total_size(payload: 4) +
1654	/* IFLA_IPTUN_LOCAL */
1655	nla_total_size(payload: 4) +
1656	/* IFLA_IPTUN_REMOTE */
1657	nla_total_size(payload: 4) +
1658	/* IFLA_IPTUN_TTL */
1659	nla_total_size(payload: 1) +
1660	/* IFLA_IPTUN_TOS */
1661	nla_total_size(payload: 1) +
1662	/* IFLA_IPTUN_PMTUDISC */
1663	nla_total_size(payload: 1) +
1664	/* IFLA_IPTUN_FLAGS */
1665	nla_total_size(payload: 2) +
1666	/* IFLA_IPTUN_PROTO */
1667	nla_total_size(payload: 1) +
1668	#ifdef CONFIG_IPV6_SIT_6RD
1669	/* IFLA_IPTUN_6RD_PREFIX */
1670	nla_total_size(payload: sizeof(struct in6_addr)) +
1671	/* IFLA_IPTUN_6RD_RELAY_PREFIX */
1672	nla_total_size(payload: 4) +
1673	/* IFLA_IPTUN_6RD_PREFIXLEN */
1674	nla_total_size(payload: 2) +
1675	/* IFLA_IPTUN_6RD_RELAY_PREFIXLEN */
1676	nla_total_size(payload: 2) +
1677	#endif
1678	/* IFLA_IPTUN_ENCAP_TYPE */
1679	nla_total_size(payload: 2) +
1680	/* IFLA_IPTUN_ENCAP_FLAGS */
1681	nla_total_size(payload: 2) +
1682	/* IFLA_IPTUN_ENCAP_SPORT */
1683	nla_total_size(payload: 2) +
1684	/* IFLA_IPTUN_ENCAP_DPORT */
1685	nla_total_size(payload: 2) +
1686	/* IFLA_IPTUN_FWMARK */
1687	nla_total_size(payload: 4) +
1688	0;
1689	}
1690
1691	static 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, attrtype: IFLA_IPTUN_LINK, value: parm->link) ||
1697	nla_put_in_addr(skb, attrtype: IFLA_IPTUN_LOCAL, addr: parm->iph.saddr) ||
1698	nla_put_in_addr(skb, attrtype: IFLA_IPTUN_REMOTE, addr: parm->iph.daddr) ||
1699	nla_put_u8(skb, attrtype: IFLA_IPTUN_TTL, value: parm->iph.ttl) ||
1700	nla_put_u8(skb, attrtype: IFLA_IPTUN_TOS, value: parm->iph.tos) ||
1701	nla_put_u8(skb, attrtype: IFLA_IPTUN_PMTUDISC,
1702	value: !!(parm->iph.frag_off & htons(IP_DF))) ||
1703	nla_put_u8(skb, attrtype: IFLA_IPTUN_PROTO, value: parm->iph.protocol) ||
1704	nla_put_be16(skb, attrtype: IFLA_IPTUN_FLAGS, value: parm->i_flags) ||
1705	nla_put_u32(skb, attrtype: IFLA_IPTUN_FWMARK, value: tunnel->fwmark))
1706	goto nla_put_failure;
1707
1708	#ifdef CONFIG_IPV6_SIT_6RD
1709	if (nla_put_in6_addr(skb, attrtype: IFLA_IPTUN_6RD_PREFIX,
1710	addr: &tunnel->ip6rd.prefix) ||
1711	nla_put_in_addr(skb, attrtype: IFLA_IPTUN_6RD_RELAY_PREFIX,
1712	addr: tunnel->ip6rd.relay_prefix) ||
1713	nla_put_u16(skb, attrtype: IFLA_IPTUN_6RD_PREFIXLEN,
1714	value: tunnel->ip6rd.prefixlen) ||
1715	nla_put_u16(skb, attrtype: IFLA_IPTUN_6RD_RELAY_PREFIXLEN,
1716	value: tunnel->ip6rd.relay_prefixlen))
1717	goto nla_put_failure;
1718	#endif
1719
1720	if (nla_put_u16(skb, attrtype: IFLA_IPTUN_ENCAP_TYPE,
1721	value: tunnel->encap.type) ||
1722	nla_put_be16(skb, attrtype: IFLA_IPTUN_ENCAP_SPORT,
1723	value: tunnel->encap.sport) ||
1724	nla_put_be16(skb, attrtype: IFLA_IPTUN_ENCAP_DPORT,
1725	value: tunnel->encap.dport) ||
1726	nla_put_u16(skb, attrtype: IFLA_IPTUN_ENCAP_FLAGS,
1727	value: tunnel->encap.flags))
1728	goto nla_put_failure;
1729
1730	return 0;
1731
1732	nla_put_failure:
1733	return -EMSGSIZE;
1734	}
1735
1736	static 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
1758	static 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, id: sit_net_id);
1762
1763	if (dev != sitn->fb_tunnel_dev)
1764	unregister_netdevice_queue(dev, head);
1765	}
1766
1767	static 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
1782	static struct xfrm_tunnel sit_handler __read_mostly = {
1783	.handler = ipip6_rcv,
1784	.err_handler = ipip6_err,
1785	.priority = 1,
1786	};
1787
1788	static 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)
1795	static struct xfrm_tunnel mplsip_handler __read_mostly = {
1796	.handler = mplsip_rcv,
1797	.err_handler = ipip6_err,
1798	.priority = 2,
1799	};
1800	#endif
1801
1802	static void __net_exit sit_destroy_tunnels(struct net *net,
1803	struct list_head *head)
1804	{
1805	struct sit_net *sitn = net_generic(net, id: 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(net1: dev_net(dev: t->dev), net2: net))
1824	unregister_netdevice_queue(dev: t->dev,
1825	head);
1826	t = rtnl_dereference(t->next);
1827	}
1828	}
1829	}
1830	}
1831
1832	static int __net_init sit_init_net(struct net *net)
1833	{
1834	struct sit_net *sitn = net_generic(net, id: 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(dev: 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(dev: sitn->fb_tunnel_dev);
1861	if (err)
1862	goto err_reg_dev;
1863
1864	ipip6_tunnel_clone_6rd(dev: sitn->fb_tunnel_dev, sitn);
1865	ipip6_fb_tunnel_init(dev: sitn->fb_tunnel_dev);
1866
1867	t = netdev_priv(dev: sitn->fb_tunnel_dev);
1868
1869	strcpy(p: t->parms.name, q: sitn->fb_tunnel_dev->name);
1870	return 0;
1871
1872	err_reg_dev:
1873	free_netdev(dev: sitn->fb_tunnel_dev);
1874	err_alloc_dev:
1875	return err;
1876	}
1877
1878	static 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, head: &list);
1886
1887	unregister_netdevice_many(head: &list);
1888	rtnl_unlock();
1889	}
1890
1891	static 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
1898	static void __exit sit_cleanup(void)
1899	{
1900	rtnl_link_unregister(ops: &sit_link_ops);
1901	xfrm4_tunnel_deregister(handler: &sit_handler, AF_INET6);
1902	xfrm4_tunnel_deregister(handler: &ipip_handler, AF_INET);
1903	#if IS_ENABLED(CONFIG_MPLS)
1904	xfrm4_tunnel_deregister(handler: &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
1911	static 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(handler: &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(handler: &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(handler: &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(ops: &sit_link_ops);
1938	if (err < 0)
1939	goto rtnl_link_failed;
1940
1941	out:
1942	return err;
1943
1944	rtnl_link_failed:
1945	#if IS_ENABLED(CONFIG_MPLS)
1946	xfrm4_tunnel_deregister(handler: &mplsip_handler, AF_MPLS);
1947	xfrm_tunnel_mpls_failed:
1948	#endif
1949	xfrm4_tunnel_deregister(handler: &ipip_handler, AF_INET);
1950	xfrm_tunnel4_failed:
1951	xfrm4_tunnel_deregister(handler: &sit_handler, AF_INET6);
1952	xfrm_tunnel_failed:
1953	unregister_pernet_device(&sit_net_ops);
1954	goto out;
1955	}
1956
1957	module_init(sit_init);
1958	module_exit(sit_cleanup);
1959	MODULE_LICENSE("GPL");
1960	MODULE_ALIAS_RTNL_LINK("sit");
1961	MODULE_ALIAS_NETDEV("sit0");
1962