1/*
2 *	IPv6 virtual tunneling interface
3 *
4 *	Copyright (C) 2013 secunet Security Networks AG
5 *
6 *	Author:
7 *	Steffen Klassert <steffen.klassert@secunet.com>
8 *
9 *	Based on:
10 *	net/ipv6/ip6_tunnel.c
11 *
12 *	This program is free software; you can redistribute it and/or
13 *	modify it under the terms of the GNU General Public License
14 *	as published by the Free Software Foundation; either version
15 *	2 of the License, or (at your option) any later version.
16 */
17
18#include <linux/module.h>
19#include <linux/capability.h>
20#include <linux/errno.h>
21#include <linux/types.h>
22#include <linux/sockios.h>
23#include <linux/icmp.h>
24#include <linux/if.h>
25#include <linux/in.h>
26#include <linux/ip.h>
27#include <linux/net.h>
28#include <linux/in6.h>
29#include <linux/netdevice.h>
30#include <linux/if_arp.h>
31#include <linux/icmpv6.h>
32#include <linux/init.h>
33#include <linux/route.h>
34#include <linux/rtnetlink.h>
35#include <linux/netfilter_ipv6.h>
36#include <linux/slab.h>
37#include <linux/hash.h>
38
39#include <linux/uaccess.h>
40#include <linux/atomic.h>
41
42#include <net/icmp.h>
43#include <net/ip.h>
44#include <net/ip_tunnels.h>
45#include <net/ipv6.h>
46#include <net/ip6_route.h>
47#include <net/addrconf.h>
48#include <net/ip6_tunnel.h>
49#include <net/xfrm.h>
50#include <net/net_namespace.h>
51#include <net/netns/generic.h>
52
53#define HASH_SIZE_SHIFT  5
54#define HASH_SIZE (1 << HASH_SIZE_SHIFT)
55
56static u32 HASH(const struct in6_addr *addr1, const struct in6_addr *addr2)
57{
58	u32 hash = ipv6_addr_hash(addr1) ^ ipv6_addr_hash(addr2);
59
60	return hash_32(hash, HASH_SIZE_SHIFT);
61}
62
63static int vti6_dev_init(struct net_device *dev);
64static void vti6_dev_setup(struct net_device *dev);
65static struct rtnl_link_ops vti6_link_ops __read_mostly;
66
67static int vti6_net_id __read_mostly;
68struct vti6_net {
69	/* the vti6 tunnel fallback device */
70	struct net_device *fb_tnl_dev;
71	/* lists for storing tunnels in use */
72	struct ip6_tnl __rcu *tnls_r_l[HASH_SIZE];
73	struct ip6_tnl __rcu *tnls_wc[1];
74	struct ip6_tnl __rcu **tnls[2];
75};
76
77#define for_each_vti6_tunnel_rcu(start) \
78	for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
79
80/**
81 * vti6_tnl_lookup - fetch tunnel matching the end-point addresses
82 *   @net: network namespace
83 *   @remote: the address of the tunnel exit-point
84 *   @local: the address of the tunnel entry-point
85 *
86 * Return:
87 *   tunnel matching given end-points if found,
88 *   else fallback tunnel if its device is up,
89 *   else %NULL
90 **/
91static struct ip6_tnl *
92vti6_tnl_lookup(struct net *net, const struct in6_addr *remote,
93		const struct in6_addr *local)
94{
95	unsigned int hash = HASH(remote, local);
96	struct ip6_tnl *t;
97	struct vti6_net *ip6n = net_generic(net, vti6_net_id);
98	struct in6_addr any;
99
100	for_each_vti6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
101		if (ipv6_addr_equal(local, &t->parms.laddr) &&
102		    ipv6_addr_equal(remote, &t->parms.raddr) &&
103		    (t->dev->flags & IFF_UP))
104			return t;
105	}
106
107	memset(&any, 0, sizeof(any));
108	hash = HASH(&any, local);
109	for_each_vti6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
110		if (ipv6_addr_equal(local, &t->parms.laddr) &&
111		    (t->dev->flags & IFF_UP))
112			return t;
113	}
114
115	hash = HASH(remote, &any);
116	for_each_vti6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
117		if (ipv6_addr_equal(remote, &t->parms.raddr) &&
118		    (t->dev->flags & IFF_UP))
119			return t;
120	}
121
122	t = rcu_dereference(ip6n->tnls_wc[0]);
123	if (t && (t->dev->flags & IFF_UP))
124		return t;
125
126	return NULL;
127}
128
129/**
130 * vti6_tnl_bucket - get head of list matching given tunnel parameters
131 *   @p: parameters containing tunnel end-points
132 *
133 * Description:
134 *   vti6_tnl_bucket() returns the head of the list matching the
135 *   &struct in6_addr entries laddr and raddr in @p.
136 *
137 * Return: head of IPv6 tunnel list
138 **/
139static struct ip6_tnl __rcu **
140vti6_tnl_bucket(struct vti6_net *ip6n, const struct __ip6_tnl_parm *p)
141{
142	const struct in6_addr *remote = &p->raddr;
143	const struct in6_addr *local = &p->laddr;
144	unsigned int h = 0;
145	int prio = 0;
146
147	if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) {
148		prio = 1;
149		h = HASH(remote, local);
150	}
151	return &ip6n->tnls[prio][h];
152}
153
154static void
155vti6_tnl_link(struct vti6_net *ip6n, struct ip6_tnl *t)
156{
157	struct ip6_tnl __rcu **tp = vti6_tnl_bucket(ip6n, &t->parms);
158
159	rcu_assign_pointer(t->next , rtnl_dereference(*tp));
160	rcu_assign_pointer(*tp, t);
161}
162
163static void
164vti6_tnl_unlink(struct vti6_net *ip6n, struct ip6_tnl *t)
165{
166	struct ip6_tnl __rcu **tp;
167	struct ip6_tnl *iter;
168
169	for (tp = vti6_tnl_bucket(ip6n, &t->parms);
170	     (iter = rtnl_dereference(*tp)) != NULL;
171	     tp = &iter->next) {
172		if (t == iter) {
173			rcu_assign_pointer(*tp, t->next);
174			break;
175		}
176	}
177}
178
179static void vti6_dev_free(struct net_device *dev)
180{
181	free_percpu(dev->tstats);
182	free_netdev(dev);
183}
184
185static int vti6_tnl_create2(struct net_device *dev)
186{
187	struct ip6_tnl *t = netdev_priv(dev);
188	struct net *net = dev_net(dev);
189	struct vti6_net *ip6n = net_generic(net, vti6_net_id);
190	int err;
191
192	err = register_netdevice(dev);
193	if (err < 0)
194		goto out;
195
196	strcpy(t->parms.name, dev->name);
197	dev->rtnl_link_ops = &vti6_link_ops;
198
199	dev_hold(dev);
200	vti6_tnl_link(ip6n, t);
201
202	return 0;
203
204out:
205	return err;
206}
207
208static struct ip6_tnl *vti6_tnl_create(struct net *net, struct __ip6_tnl_parm *p)
209{
210	struct net_device *dev;
211	struct ip6_tnl *t;
212	char name[IFNAMSIZ];
213	int err;
214
215	if (p->name[0])
216		strlcpy(name, p->name, IFNAMSIZ);
217	else
218		sprintf(name, "ip6_vti%%d");
219
220	dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN, vti6_dev_setup);
221	if (!dev)
222		goto failed;
223
224	dev_net_set(dev, net);
225
226	t = netdev_priv(dev);
227	t->parms = *p;
228	t->net = dev_net(dev);
229
230	err = vti6_tnl_create2(dev);
231	if (err < 0)
232		goto failed_free;
233
234	return t;
235
236failed_free:
237	vti6_dev_free(dev);
238failed:
239	return NULL;
240}
241
242/**
243 * vti6_locate - find or create tunnel matching given parameters
244 *   @net: network namespace
245 *   @p: tunnel parameters
246 *   @create: != 0 if allowed to create new tunnel if no match found
247 *
248 * Description:
249 *   vti6_locate() first tries to locate an existing tunnel
250 *   based on @parms. If this is unsuccessful, but @create is set a new
251 *   tunnel device is created and registered for use.
252 *
253 * Return:
254 *   matching tunnel or NULL
255 **/
256static struct ip6_tnl *vti6_locate(struct net *net, struct __ip6_tnl_parm *p,
257				   int create)
258{
259	const struct in6_addr *remote = &p->raddr;
260	const struct in6_addr *local = &p->laddr;
261	struct ip6_tnl __rcu **tp;
262	struct ip6_tnl *t;
263	struct vti6_net *ip6n = net_generic(net, vti6_net_id);
264
265	for (tp = vti6_tnl_bucket(ip6n, p);
266	     (t = rtnl_dereference(*tp)) != NULL;
267	     tp = &t->next) {
268		if (ipv6_addr_equal(local, &t->parms.laddr) &&
269		    ipv6_addr_equal(remote, &t->parms.raddr)) {
270			if (create)
271				return NULL;
272
273			return t;
274		}
275	}
276	if (!create)
277		return NULL;
278	return vti6_tnl_create(net, p);
279}
280
281/**
282 * vti6_dev_uninit - tunnel device uninitializer
283 *   @dev: the device to be destroyed
284 *
285 * Description:
286 *   vti6_dev_uninit() removes tunnel from its list
287 **/
288static void vti6_dev_uninit(struct net_device *dev)
289{
290	struct ip6_tnl *t = netdev_priv(dev);
291	struct vti6_net *ip6n = net_generic(t->net, vti6_net_id);
292
293	if (dev == ip6n->fb_tnl_dev)
294		RCU_INIT_POINTER(ip6n->tnls_wc[0], NULL);
295	else
296		vti6_tnl_unlink(ip6n, t);
297	dev_put(dev);
298}
299
300static int vti6_rcv(struct sk_buff *skb)
301{
302	struct ip6_tnl *t;
303	const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
304
305	rcu_read_lock();
306	t = vti6_tnl_lookup(dev_net(skb->dev), &ipv6h->saddr, &ipv6h->daddr);
307	if (t) {
308		if (t->parms.proto != IPPROTO_IPV6 && t->parms.proto != 0) {
309			rcu_read_unlock();
310			goto discard;
311		}
312
313		if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
314			rcu_read_unlock();
315			return 0;
316		}
317
318		if (!ip6_tnl_rcv_ctl(t, &ipv6h->daddr, &ipv6h->saddr)) {
319			t->dev->stats.rx_dropped++;
320			rcu_read_unlock();
321			goto discard;
322		}
323
324		XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 = t;
325
326		rcu_read_unlock();
327
328		return xfrm6_rcv(skb);
329	}
330	rcu_read_unlock();
331	return -EINVAL;
332discard:
333	kfree_skb(skb);
334	return 0;
335}
336
337static int vti6_rcv_cb(struct sk_buff *skb, int err)
338{
339	unsigned short family;
340	struct net_device *dev;
341	struct pcpu_sw_netstats *tstats;
342	struct xfrm_state *x;
343	struct ip6_tnl *t = XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6;
344	u32 orig_mark = skb->mark;
345	int ret;
346
347	if (!t)
348		return 1;
349
350	dev = t->dev;
351
352	if (err) {
353		dev->stats.rx_errors++;
354		dev->stats.rx_dropped++;
355
356		return 0;
357	}
358
359	x = xfrm_input_state(skb);
360	family = x->inner_mode->afinfo->family;
361
362	skb->mark = be32_to_cpu(t->parms.i_key);
363	ret = xfrm_policy_check(NULL, XFRM_POLICY_IN, skb, family);
364	skb->mark = orig_mark;
365
366	if (!ret)
367		return -EPERM;
368
369	skb_scrub_packet(skb, !net_eq(t->net, dev_net(skb->dev)));
370	skb->dev = dev;
371
372	tstats = this_cpu_ptr(dev->tstats);
373	u64_stats_update_begin(&tstats->syncp);
374	tstats->rx_packets++;
375	tstats->rx_bytes += skb->len;
376	u64_stats_update_end(&tstats->syncp);
377
378	return 0;
379}
380
381/**
382 * vti6_addr_conflict - compare packet addresses to tunnel's own
383 *   @t: the outgoing tunnel device
384 *   @hdr: IPv6 header from the incoming packet
385 *
386 * Description:
387 *   Avoid trivial tunneling loop by checking that tunnel exit-point
388 *   doesn't match source of incoming packet.
389 *
390 * Return:
391 *   1 if conflict,
392 *   0 else
393 **/
394static inline bool
395vti6_addr_conflict(const struct ip6_tnl *t, const struct ipv6hdr *hdr)
396{
397	return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
398}
399
400static bool vti6_state_check(const struct xfrm_state *x,
401			     const struct in6_addr *dst,
402			     const struct in6_addr *src)
403{
404	xfrm_address_t *daddr = (xfrm_address_t *)dst;
405	xfrm_address_t *saddr = (xfrm_address_t *)src;
406
407	/* if there is no transform then this tunnel is not functional.
408	 * Or if the xfrm is not mode tunnel.
409	 */
410	if (!x || x->props.mode != XFRM_MODE_TUNNEL ||
411	    x->props.family != AF_INET6)
412		return false;
413
414	if (ipv6_addr_any(dst))
415		return xfrm_addr_equal(saddr, &x->props.saddr, AF_INET6);
416
417	if (!xfrm_state_addr_check(x, daddr, saddr, AF_INET6))
418		return false;
419
420	return true;
421}
422
423/**
424 * vti6_xmit - send a packet
425 *   @skb: the outgoing socket buffer
426 *   @dev: the outgoing tunnel device
427 *   @fl: the flow informations for the xfrm_lookup
428 **/
429static int
430vti6_xmit(struct sk_buff *skb, struct net_device *dev, struct flowi *fl)
431{
432	struct ip6_tnl *t = netdev_priv(dev);
433	struct net_device_stats *stats = &t->dev->stats;
434	struct dst_entry *dst = skb_dst(skb);
435	struct net_device *tdev;
436	struct xfrm_state *x;
437	int err = -1;
438	int mtu;
439
440	if (!dst)
441		goto tx_err_link_failure;
442
443	dst_hold(dst);
444	dst = xfrm_lookup(t->net, dst, fl, NULL, 0);
445	if (IS_ERR(dst)) {
446		err = PTR_ERR(dst);
447		dst = NULL;
448		goto tx_err_link_failure;
449	}
450
451	x = dst->xfrm;
452	if (!vti6_state_check(x, &t->parms.raddr, &t->parms.laddr))
453		goto tx_err_link_failure;
454
455	if (!ip6_tnl_xmit_ctl(t, (const struct in6_addr *)&x->props.saddr,
456			      (const struct in6_addr *)&x->id.daddr))
457		goto tx_err_link_failure;
458
459	tdev = dst->dev;
460
461	if (tdev == dev) {
462		stats->collisions++;
463		net_warn_ratelimited("%s: Local routing loop detected!\n",
464				     t->parms.name);
465		goto tx_err_dst_release;
466	}
467
468	skb_scrub_packet(skb, !net_eq(t->net, dev_net(dev)));
469	skb_dst_set(skb, dst);
470	skb->dev = skb_dst(skb)->dev;
471
472	mtu = dst_mtu(dst);
473	if (!skb->ignore_df && skb->len > mtu) {
474		skb_dst(skb)->ops->update_pmtu(dst, NULL, skb, mtu);
475
476		if (skb->protocol == htons(ETH_P_IPV6))
477			icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
478		else
479			icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
480				  htonl(mtu));
481
482		return -EMSGSIZE;
483	}
484
485	err = dst_output(t->net, skb->sk, skb);
486	if (net_xmit_eval(err) == 0) {
487		struct pcpu_sw_netstats *tstats = this_cpu_ptr(dev->tstats);
488
489		u64_stats_update_begin(&tstats->syncp);
490		tstats->tx_bytes += skb->len;
491		tstats->tx_packets++;
492		u64_stats_update_end(&tstats->syncp);
493	} else {
494		stats->tx_errors++;
495		stats->tx_aborted_errors++;
496	}
497
498	return 0;
499tx_err_link_failure:
500	stats->tx_carrier_errors++;
501	dst_link_failure(skb);
502tx_err_dst_release:
503	dst_release(dst);
504	return err;
505}
506
507static netdev_tx_t
508vti6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
509{
510	struct ip6_tnl *t = netdev_priv(dev);
511	struct net_device_stats *stats = &t->dev->stats;
512	struct ipv6hdr *ipv6h;
513	struct flowi fl;
514	int ret;
515
516	memset(&fl, 0, sizeof(fl));
517
518	switch (skb->protocol) {
519	case htons(ETH_P_IPV6):
520		ipv6h = ipv6_hdr(skb);
521
522		if ((t->parms.proto != IPPROTO_IPV6 && t->parms.proto != 0) ||
523		    vti6_addr_conflict(t, ipv6h))
524			goto tx_err;
525
526		xfrm_decode_session(skb, &fl, AF_INET6);
527		memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
528		break;
529	case htons(ETH_P_IP):
530		xfrm_decode_session(skb, &fl, AF_INET);
531		memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
532		break;
533	default:
534		goto tx_err;
535	}
536
537	/* override mark with tunnel output key */
538	fl.flowi_mark = be32_to_cpu(t->parms.o_key);
539
540	ret = vti6_xmit(skb, dev, &fl);
541	if (ret < 0)
542		goto tx_err;
543
544	return NETDEV_TX_OK;
545
546tx_err:
547	stats->tx_errors++;
548	stats->tx_dropped++;
549	kfree_skb(skb);
550	return NETDEV_TX_OK;
551}
552
553static int vti6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
554		    u8 type, u8 code, int offset, __be32 info)
555{
556	__be32 spi;
557	__u32 mark;
558	struct xfrm_state *x;
559	struct ip6_tnl *t;
560	struct ip_esp_hdr *esph;
561	struct ip_auth_hdr *ah;
562	struct ip_comp_hdr *ipch;
563	struct net *net = dev_net(skb->dev);
564	const struct ipv6hdr *iph = (const struct ipv6hdr *)skb->data;
565	int protocol = iph->nexthdr;
566
567	t = vti6_tnl_lookup(dev_net(skb->dev), &iph->daddr, &iph->saddr);
568	if (!t)
569		return -1;
570
571	mark = be32_to_cpu(t->parms.o_key);
572
573	switch (protocol) {
574	case IPPROTO_ESP:
575		esph = (struct ip_esp_hdr *)(skb->data + offset);
576		spi = esph->spi;
577		break;
578	case IPPROTO_AH:
579		ah = (struct ip_auth_hdr *)(skb->data + offset);
580		spi = ah->spi;
581		break;
582	case IPPROTO_COMP:
583		ipch = (struct ip_comp_hdr *)(skb->data + offset);
584		spi = htonl(ntohs(ipch->cpi));
585		break;
586	default:
587		return 0;
588	}
589
590	if (type != ICMPV6_PKT_TOOBIG &&
591	    type != NDISC_REDIRECT)
592		return 0;
593
594	x = xfrm_state_lookup(net, mark, (const xfrm_address_t *)&iph->daddr,
595			      spi, protocol, AF_INET6);
596	if (!x)
597		return 0;
598
599	if (type == NDISC_REDIRECT)
600		ip6_redirect(skb, net, skb->dev->ifindex, 0);
601	else
602		ip6_update_pmtu(skb, net, info, 0, 0);
603	xfrm_state_put(x);
604
605	return 0;
606}
607
608static void vti6_link_config(struct ip6_tnl *t)
609{
610	struct net_device *dev = t->dev;
611	struct __ip6_tnl_parm *p = &t->parms;
612
613	memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
614	memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
615
616	p->flags &= ~(IP6_TNL_F_CAP_XMIT | IP6_TNL_F_CAP_RCV |
617		      IP6_TNL_F_CAP_PER_PACKET);
618	p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
619
620	if (p->flags & IP6_TNL_F_CAP_XMIT && p->flags & IP6_TNL_F_CAP_RCV)
621		dev->flags |= IFF_POINTOPOINT;
622	else
623		dev->flags &= ~IFF_POINTOPOINT;
624}
625
626/**
627 * vti6_tnl_change - update the tunnel parameters
628 *   @t: tunnel to be changed
629 *   @p: tunnel configuration parameters
630 *
631 * Description:
632 *   vti6_tnl_change() updates the tunnel parameters
633 **/
634static int
635vti6_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p)
636{
637	t->parms.laddr = p->laddr;
638	t->parms.raddr = p->raddr;
639	t->parms.link = p->link;
640	t->parms.i_key = p->i_key;
641	t->parms.o_key = p->o_key;
642	t->parms.proto = p->proto;
643	ip6_tnl_dst_reset(t);
644	vti6_link_config(t);
645	return 0;
646}
647
648static int vti6_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
649{
650	struct net *net = dev_net(t->dev);
651	struct vti6_net *ip6n = net_generic(net, vti6_net_id);
652	int err;
653
654	vti6_tnl_unlink(ip6n, t);
655	synchronize_net();
656	err = vti6_tnl_change(t, p);
657	vti6_tnl_link(ip6n, t);
658	netdev_state_change(t->dev);
659	return err;
660}
661
662static void
663vti6_parm_from_user(struct __ip6_tnl_parm *p, const struct ip6_tnl_parm2 *u)
664{
665	p->laddr = u->laddr;
666	p->raddr = u->raddr;
667	p->link = u->link;
668	p->i_key = u->i_key;
669	p->o_key = u->o_key;
670	p->proto = u->proto;
671
672	memcpy(p->name, u->name, sizeof(u->name));
673}
674
675static void
676vti6_parm_to_user(struct ip6_tnl_parm2 *u, const struct __ip6_tnl_parm *p)
677{
678	u->laddr = p->laddr;
679	u->raddr = p->raddr;
680	u->link = p->link;
681	u->i_key = p->i_key;
682	u->o_key = p->o_key;
683	u->proto = p->proto;
684
685	memcpy(u->name, p->name, sizeof(u->name));
686}
687
688/**
689 * vti6_tnl_ioctl - configure vti6 tunnels from userspace
690 *   @dev: virtual device associated with tunnel
691 *   @ifr: parameters passed from userspace
692 *   @cmd: command to be performed
693 *
694 * Description:
695 *   vti6_ioctl() is used for managing vti6 tunnels
696 *   from userspace.
697 *
698 *   The possible commands are the following:
699 *     %SIOCGETTUNNEL: get tunnel parameters for device
700 *     %SIOCADDTUNNEL: add tunnel matching given tunnel parameters
701 *     %SIOCCHGTUNNEL: change tunnel parameters to those given
702 *     %SIOCDELTUNNEL: delete tunnel
703 *
704 *   The fallback device "ip6_vti0", created during module
705 *   initialization, can be used for creating other tunnel devices.
706 *
707 * Return:
708 *   0 on success,
709 *   %-EFAULT if unable to copy data to or from userspace,
710 *   %-EPERM if current process hasn't %CAP_NET_ADMIN set
711 *   %-EINVAL if passed tunnel parameters are invalid,
712 *   %-EEXIST if changing a tunnel's parameters would cause a conflict
713 *   %-ENODEV if attempting to change or delete a nonexisting device
714 **/
715static int
716vti6_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
717{
718	int err = 0;
719	struct ip6_tnl_parm2 p;
720	struct __ip6_tnl_parm p1;
721	struct ip6_tnl *t = NULL;
722	struct net *net = dev_net(dev);
723	struct vti6_net *ip6n = net_generic(net, vti6_net_id);
724
725	switch (cmd) {
726	case SIOCGETTUNNEL:
727		if (dev == ip6n->fb_tnl_dev) {
728			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
729				err = -EFAULT;
730				break;
731			}
732			vti6_parm_from_user(&p1, &p);
733			t = vti6_locate(net, &p1, 0);
734		} else {
735			memset(&p, 0, sizeof(p));
736		}
737		if (!t)
738			t = netdev_priv(dev);
739		vti6_parm_to_user(&p, &t->parms);
740		if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
741			err = -EFAULT;
742		break;
743	case SIOCADDTUNNEL:
744	case SIOCCHGTUNNEL:
745		err = -EPERM;
746		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
747			break;
748		err = -EFAULT;
749		if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
750			break;
751		err = -EINVAL;
752		if (p.proto != IPPROTO_IPV6  && p.proto != 0)
753			break;
754		vti6_parm_from_user(&p1, &p);
755		t = vti6_locate(net, &p1, cmd == SIOCADDTUNNEL);
756		if (dev != ip6n->fb_tnl_dev && cmd == SIOCCHGTUNNEL) {
757			if (t) {
758				if (t->dev != dev) {
759					err = -EEXIST;
760					break;
761				}
762			} else
763				t = netdev_priv(dev);
764
765			err = vti6_update(t, &p1);
766		}
767		if (t) {
768			err = 0;
769			vti6_parm_to_user(&p, &t->parms);
770			if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
771				err = -EFAULT;
772
773		} else
774			err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
775		break;
776	case SIOCDELTUNNEL:
777		err = -EPERM;
778		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
779			break;
780
781		if (dev == ip6n->fb_tnl_dev) {
782			err = -EFAULT;
783			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
784				break;
785			err = -ENOENT;
786			vti6_parm_from_user(&p1, &p);
787			t = vti6_locate(net, &p1, 0);
788			if (!t)
789				break;
790			err = -EPERM;
791			if (t->dev == ip6n->fb_tnl_dev)
792				break;
793			dev = t->dev;
794		}
795		err = 0;
796		unregister_netdevice(dev);
797		break;
798	default:
799		err = -EINVAL;
800	}
801	return err;
802}
803
804/**
805 * vti6_tnl_change_mtu - change mtu manually for tunnel device
806 *   @dev: virtual device associated with tunnel
807 *   @new_mtu: the new mtu
808 *
809 * Return:
810 *   0 on success,
811 *   %-EINVAL if mtu too small
812 **/
813static int vti6_change_mtu(struct net_device *dev, int new_mtu)
814{
815	if (new_mtu < IPV6_MIN_MTU)
816		return -EINVAL;
817
818	dev->mtu = new_mtu;
819	return 0;
820}
821
822static const struct net_device_ops vti6_netdev_ops = {
823	.ndo_init	= vti6_dev_init,
824	.ndo_uninit	= vti6_dev_uninit,
825	.ndo_start_xmit = vti6_tnl_xmit,
826	.ndo_do_ioctl	= vti6_ioctl,
827	.ndo_change_mtu = vti6_change_mtu,
828	.ndo_get_stats64 = ip_tunnel_get_stats64,
829	.ndo_get_iflink = ip6_tnl_get_iflink,
830};
831
832/**
833 * vti6_dev_setup - setup virtual tunnel device
834 *   @dev: virtual device associated with tunnel
835 *
836 * Description:
837 *   Initialize function pointers and device parameters
838 **/
839static void vti6_dev_setup(struct net_device *dev)
840{
841	dev->netdev_ops = &vti6_netdev_ops;
842	dev->destructor = vti6_dev_free;
843
844	dev->type = ARPHRD_TUNNEL6;
845	dev->hard_header_len = LL_MAX_HEADER + sizeof(struct ipv6hdr);
846	dev->mtu = ETH_DATA_LEN;
847	dev->flags |= IFF_NOARP;
848	dev->addr_len = sizeof(struct in6_addr);
849	netif_keep_dst(dev);
850}
851
852/**
853 * vti6_dev_init_gen - general initializer for all tunnel devices
854 *   @dev: virtual device associated with tunnel
855 **/
856static inline int vti6_dev_init_gen(struct net_device *dev)
857{
858	struct ip6_tnl *t = netdev_priv(dev);
859
860	t->dev = dev;
861	t->net = dev_net(dev);
862	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
863	if (!dev->tstats)
864		return -ENOMEM;
865	return 0;
866}
867
868/**
869 * vti6_dev_init - initializer for all non fallback tunnel devices
870 *   @dev: virtual device associated with tunnel
871 **/
872static int vti6_dev_init(struct net_device *dev)
873{
874	struct ip6_tnl *t = netdev_priv(dev);
875	int err = vti6_dev_init_gen(dev);
876
877	if (err)
878		return err;
879	vti6_link_config(t);
880	return 0;
881}
882
883/**
884 * vti6_fb_tnl_dev_init - initializer for fallback tunnel device
885 *   @dev: fallback device
886 *
887 * Return: 0
888 **/
889static int __net_init vti6_fb_tnl_dev_init(struct net_device *dev)
890{
891	struct ip6_tnl *t = netdev_priv(dev);
892	struct net *net = dev_net(dev);
893	struct vti6_net *ip6n = net_generic(net, vti6_net_id);
894
895	t->parms.proto = IPPROTO_IPV6;
896	dev_hold(dev);
897
898	rcu_assign_pointer(ip6n->tnls_wc[0], t);
899	return 0;
900}
901
902static int vti6_validate(struct nlattr *tb[], struct nlattr *data[])
903{
904	return 0;
905}
906
907static void vti6_netlink_parms(struct nlattr *data[],
908			       struct __ip6_tnl_parm *parms)
909{
910	memset(parms, 0, sizeof(*parms));
911
912	if (!data)
913		return;
914
915	if (data[IFLA_VTI_LINK])
916		parms->link = nla_get_u32(data[IFLA_VTI_LINK]);
917
918	if (data[IFLA_VTI_LOCAL])
919		parms->laddr = nla_get_in6_addr(data[IFLA_VTI_LOCAL]);
920
921	if (data[IFLA_VTI_REMOTE])
922		parms->raddr = nla_get_in6_addr(data[IFLA_VTI_REMOTE]);
923
924	if (data[IFLA_VTI_IKEY])
925		parms->i_key = nla_get_be32(data[IFLA_VTI_IKEY]);
926
927	if (data[IFLA_VTI_OKEY])
928		parms->o_key = nla_get_be32(data[IFLA_VTI_OKEY]);
929}
930
931static int vti6_newlink(struct net *src_net, struct net_device *dev,
932			struct nlattr *tb[], struct nlattr *data[])
933{
934	struct net *net = dev_net(dev);
935	struct ip6_tnl *nt;
936
937	nt = netdev_priv(dev);
938	vti6_netlink_parms(data, &nt->parms);
939
940	nt->parms.proto = IPPROTO_IPV6;
941
942	if (vti6_locate(net, &nt->parms, 0))
943		return -EEXIST;
944
945	return vti6_tnl_create2(dev);
946}
947
948static void vti6_dellink(struct net_device *dev, struct list_head *head)
949{
950	struct net *net = dev_net(dev);
951	struct vti6_net *ip6n = net_generic(net, vti6_net_id);
952
953	if (dev != ip6n->fb_tnl_dev)
954		unregister_netdevice_queue(dev, head);
955}
956
957static int vti6_changelink(struct net_device *dev, struct nlattr *tb[],
958			   struct nlattr *data[])
959{
960	struct ip6_tnl *t;
961	struct __ip6_tnl_parm p;
962	struct net *net = dev_net(dev);
963	struct vti6_net *ip6n = net_generic(net, vti6_net_id);
964
965	if (dev == ip6n->fb_tnl_dev)
966		return -EINVAL;
967
968	vti6_netlink_parms(data, &p);
969
970	t = vti6_locate(net, &p, 0);
971
972	if (t) {
973		if (t->dev != dev)
974			return -EEXIST;
975	} else
976		t = netdev_priv(dev);
977
978	return vti6_update(t, &p);
979}
980
981static size_t vti6_get_size(const struct net_device *dev)
982{
983	return
984		/* IFLA_VTI_LINK */
985		nla_total_size(4) +
986		/* IFLA_VTI_LOCAL */
987		nla_total_size(sizeof(struct in6_addr)) +
988		/* IFLA_VTI_REMOTE */
989		nla_total_size(sizeof(struct in6_addr)) +
990		/* IFLA_VTI_IKEY */
991		nla_total_size(4) +
992		/* IFLA_VTI_OKEY */
993		nla_total_size(4) +
994		0;
995}
996
997static int vti6_fill_info(struct sk_buff *skb, const struct net_device *dev)
998{
999	struct ip6_tnl *tunnel = netdev_priv(dev);
1000	struct __ip6_tnl_parm *parm = &tunnel->parms;
1001
1002	if (nla_put_u32(skb, IFLA_VTI_LINK, parm->link) ||
1003	    nla_put_in6_addr(skb, IFLA_VTI_LOCAL, &parm->laddr) ||
1004	    nla_put_in6_addr(skb, IFLA_VTI_REMOTE, &parm->raddr) ||
1005	    nla_put_be32(skb, IFLA_VTI_IKEY, parm->i_key) ||
1006	    nla_put_be32(skb, IFLA_VTI_OKEY, parm->o_key))
1007		goto nla_put_failure;
1008	return 0;
1009
1010nla_put_failure:
1011	return -EMSGSIZE;
1012}
1013
1014static const struct nla_policy vti6_policy[IFLA_VTI_MAX + 1] = {
1015	[IFLA_VTI_LINK]		= { .type = NLA_U32 },
1016	[IFLA_VTI_LOCAL]	= { .len = sizeof(struct in6_addr) },
1017	[IFLA_VTI_REMOTE]	= { .len = sizeof(struct in6_addr) },
1018	[IFLA_VTI_IKEY]		= { .type = NLA_U32 },
1019	[IFLA_VTI_OKEY]		= { .type = NLA_U32 },
1020};
1021
1022static struct rtnl_link_ops vti6_link_ops __read_mostly = {
1023	.kind		= "vti6",
1024	.maxtype	= IFLA_VTI_MAX,
1025	.policy		= vti6_policy,
1026	.priv_size	= sizeof(struct ip6_tnl),
1027	.setup		= vti6_dev_setup,
1028	.validate	= vti6_validate,
1029	.newlink	= vti6_newlink,
1030	.dellink	= vti6_dellink,
1031	.changelink	= vti6_changelink,
1032	.get_size	= vti6_get_size,
1033	.fill_info	= vti6_fill_info,
1034	.get_link_net	= ip6_tnl_get_link_net,
1035};
1036
1037static void __net_exit vti6_destroy_tunnels(struct vti6_net *ip6n)
1038{
1039	int h;
1040	struct ip6_tnl *t;
1041	LIST_HEAD(list);
1042
1043	for (h = 0; h < HASH_SIZE; h++) {
1044		t = rtnl_dereference(ip6n->tnls_r_l[h]);
1045		while (t) {
1046			unregister_netdevice_queue(t->dev, &list);
1047			t = rtnl_dereference(t->next);
1048		}
1049	}
1050
1051	t = rtnl_dereference(ip6n->tnls_wc[0]);
1052	unregister_netdevice_queue(t->dev, &list);
1053	unregister_netdevice_many(&list);
1054}
1055
1056static int __net_init vti6_init_net(struct net *net)
1057{
1058	struct vti6_net *ip6n = net_generic(net, vti6_net_id);
1059	struct ip6_tnl *t = NULL;
1060	int err;
1061
1062	ip6n->tnls[0] = ip6n->tnls_wc;
1063	ip6n->tnls[1] = ip6n->tnls_r_l;
1064
1065	err = -ENOMEM;
1066	ip6n->fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6_vti0",
1067					NET_NAME_UNKNOWN, vti6_dev_setup);
1068
1069	if (!ip6n->fb_tnl_dev)
1070		goto err_alloc_dev;
1071	dev_net_set(ip6n->fb_tnl_dev, net);
1072	ip6n->fb_tnl_dev->rtnl_link_ops = &vti6_link_ops;
1073
1074	err = vti6_fb_tnl_dev_init(ip6n->fb_tnl_dev);
1075	if (err < 0)
1076		goto err_register;
1077
1078	err = register_netdev(ip6n->fb_tnl_dev);
1079	if (err < 0)
1080		goto err_register;
1081
1082	t = netdev_priv(ip6n->fb_tnl_dev);
1083
1084	strcpy(t->parms.name, ip6n->fb_tnl_dev->name);
1085	return 0;
1086
1087err_register:
1088	vti6_dev_free(ip6n->fb_tnl_dev);
1089err_alloc_dev:
1090	return err;
1091}
1092
1093static void __net_exit vti6_exit_net(struct net *net)
1094{
1095	struct vti6_net *ip6n = net_generic(net, vti6_net_id);
1096
1097	rtnl_lock();
1098	vti6_destroy_tunnels(ip6n);
1099	rtnl_unlock();
1100}
1101
1102static struct pernet_operations vti6_net_ops = {
1103	.init = vti6_init_net,
1104	.exit = vti6_exit_net,
1105	.id   = &vti6_net_id,
1106	.size = sizeof(struct vti6_net),
1107};
1108
1109static struct xfrm6_protocol vti_esp6_protocol __read_mostly = {
1110	.handler	=	vti6_rcv,
1111	.cb_handler	=	vti6_rcv_cb,
1112	.err_handler	=	vti6_err,
1113	.priority	=	100,
1114};
1115
1116static struct xfrm6_protocol vti_ah6_protocol __read_mostly = {
1117	.handler	=	vti6_rcv,
1118	.cb_handler	=	vti6_rcv_cb,
1119	.err_handler	=	vti6_err,
1120	.priority	=	100,
1121};
1122
1123static struct xfrm6_protocol vti_ipcomp6_protocol __read_mostly = {
1124	.handler	=	vti6_rcv,
1125	.cb_handler	=	vti6_rcv_cb,
1126	.err_handler	=	vti6_err,
1127	.priority	=	100,
1128};
1129
1130/**
1131 * vti6_tunnel_init - register protocol and reserve needed resources
1132 *
1133 * Return: 0 on success
1134 **/
1135static int __init vti6_tunnel_init(void)
1136{
1137	const char *msg;
1138	int err;
1139
1140	msg = "tunnel device";
1141	err = register_pernet_device(&vti6_net_ops);
1142	if (err < 0)
1143		goto pernet_dev_failed;
1144
1145	msg = "tunnel protocols";
1146	err = xfrm6_protocol_register(&vti_esp6_protocol, IPPROTO_ESP);
1147	if (err < 0)
1148		goto xfrm_proto_esp_failed;
1149	err = xfrm6_protocol_register(&vti_ah6_protocol, IPPROTO_AH);
1150	if (err < 0)
1151		goto xfrm_proto_ah_failed;
1152	err = xfrm6_protocol_register(&vti_ipcomp6_protocol, IPPROTO_COMP);
1153	if (err < 0)
1154		goto xfrm_proto_comp_failed;
1155
1156	msg = "netlink interface";
1157	err = rtnl_link_register(&vti6_link_ops);
1158	if (err < 0)
1159		goto rtnl_link_failed;
1160
1161	return 0;
1162
1163rtnl_link_failed:
1164	xfrm6_protocol_deregister(&vti_ipcomp6_protocol, IPPROTO_COMP);
1165xfrm_proto_comp_failed:
1166	xfrm6_protocol_deregister(&vti_ah6_protocol, IPPROTO_AH);
1167xfrm_proto_ah_failed:
1168	xfrm6_protocol_deregister(&vti_esp6_protocol, IPPROTO_ESP);
1169xfrm_proto_esp_failed:
1170	unregister_pernet_device(&vti6_net_ops);
1171pernet_dev_failed:
1172	pr_err("vti6 init: failed to register %s\n", msg);
1173	return err;
1174}
1175
1176/**
1177 * vti6_tunnel_cleanup - free resources and unregister protocol
1178 **/
1179static void __exit vti6_tunnel_cleanup(void)
1180{
1181	rtnl_link_unregister(&vti6_link_ops);
1182	xfrm6_protocol_deregister(&vti_ipcomp6_protocol, IPPROTO_COMP);
1183	xfrm6_protocol_deregister(&vti_ah6_protocol, IPPROTO_AH);
1184	xfrm6_protocol_deregister(&vti_esp6_protocol, IPPROTO_ESP);
1185	unregister_pernet_device(&vti6_net_ops);
1186}
1187
1188module_init(vti6_tunnel_init);
1189module_exit(vti6_tunnel_cleanup);
1190MODULE_LICENSE("GPL");
1191MODULE_ALIAS_RTNL_LINK("vti6");
1192MODULE_ALIAS_NETDEV("ip6_vti0");
1193MODULE_AUTHOR("Steffen Klassert");
1194MODULE_DESCRIPTION("IPv6 virtual tunnel interface");
1195