xref: /linux/net/ipv6/ip6_vti.c (revision 3e20009988e2470063824c58b19d1c80816cc46d)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *	IPv6 virtual tunneling interface
4  *
5  *	Copyright (C) 2013 secunet Security Networks AG
6  *
7  *	Author:
8  *	Steffen Klassert <steffen.klassert@secunet.com>
9  *
10  *	Based on:
11  *	net/ipv6/ip6_tunnel.c
12  */
13 
14 #include <linux/module.h>
15 #include <linux/capability.h>
16 #include <linux/errno.h>
17 #include <linux/types.h>
18 #include <linux/sockios.h>
19 #include <linux/icmp.h>
20 #include <linux/if.h>
21 #include <linux/in.h>
22 #include <linux/ip.h>
23 #include <linux/net.h>
24 #include <linux/in6.h>
25 #include <linux/netdevice.h>
26 #include <linux/if_arp.h>
27 #include <linux/icmpv6.h>
28 #include <linux/init.h>
29 #include <linux/route.h>
30 #include <linux/rtnetlink.h>
31 #include <linux/netfilter_ipv6.h>
32 #include <linux/slab.h>
33 #include <linux/hash.h>
34 
35 #include <linux/uaccess.h>
36 #include <linux/atomic.h>
37 
38 #include <net/icmp.h>
39 #include <net/ip.h>
40 #include <net/ip_tunnels.h>
41 #include <net/ipv6.h>
42 #include <net/ip6_route.h>
43 #include <net/addrconf.h>
44 #include <net/ip6_tunnel.h>
45 #include <net/xfrm.h>
46 #include <net/net_namespace.h>
47 #include <net/netns/generic.h>
48 #include <net/netdev_lock.h>
49 #include <linux/etherdevice.h>
50 
51 #define IP6_VTI_HASH_SIZE_SHIFT  5
52 #define IP6_VTI_HASH_SIZE (1 << IP6_VTI_HASH_SIZE_SHIFT)
53 
HASH(const struct in6_addr * addr1,const struct in6_addr * addr2)54 static u32 HASH(const struct in6_addr *addr1, const struct in6_addr *addr2)
55 {
56 	u32 hash = ipv6_addr_hash(addr1) ^ ipv6_addr_hash(addr2);
57 
58 	return hash_32(hash, IP6_VTI_HASH_SIZE_SHIFT);
59 }
60 
61 static int vti6_dev_init(struct net_device *dev);
62 static void vti6_dev_setup(struct net_device *dev);
63 static struct rtnl_link_ops vti6_link_ops __read_mostly;
64 
65 static unsigned int vti6_net_id __read_mostly;
66 struct vti6_net {
67 	/* the vti6 tunnel fallback device */
68 	struct net_device *fb_tnl_dev;
69 	/* lists for storing tunnels in use */
70 	struct ip6_tnl __rcu *tnls_r_l[IP6_VTI_HASH_SIZE];
71 	struct ip6_tnl __rcu *tnls_wc[1];
72 	struct ip6_tnl __rcu **tnls[2];
73 };
74 
75 #define for_each_vti6_tunnel_rcu(start) \
76 	for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
77 
78 /**
79  * vti6_tnl_lookup - fetch tunnel matching the end-point addresses
80  *   @net: network namespace
81  *   @remote: the address of the tunnel exit-point
82  *   @local: the address of the tunnel entry-point
83  *
84  * Return:
85  *   tunnel matching given end-points if found,
86  *   else fallback tunnel if its device is up,
87  *   else %NULL
88  **/
89 static struct ip6_tnl *
vti6_tnl_lookup(struct net * net,const struct in6_addr * remote,const struct in6_addr * local)90 vti6_tnl_lookup(struct net *net, const struct in6_addr *remote,
91 		const struct in6_addr *local)
92 {
93 	unsigned int hash = HASH(remote, local);
94 	struct ip6_tnl *t;
95 	struct vti6_net *ip6n = net_generic(net, vti6_net_id);
96 	struct in6_addr any;
97 
98 	for_each_vti6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
99 		if (ipv6_addr_equal(local, &t->parms.laddr) &&
100 		    ipv6_addr_equal(remote, &t->parms.raddr) &&
101 		    (t->dev->flags & IFF_UP))
102 			return t;
103 	}
104 
105 	memset(&any, 0, sizeof(any));
106 	hash = HASH(&any, local);
107 	for_each_vti6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
108 		if (ipv6_addr_equal(local, &t->parms.laddr) &&
109 		    (t->dev->flags & IFF_UP))
110 			return t;
111 	}
112 
113 	hash = HASH(remote, &any);
114 	for_each_vti6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
115 		if (ipv6_addr_equal(remote, &t->parms.raddr) &&
116 		    (t->dev->flags & IFF_UP))
117 			return t;
118 	}
119 
120 	t = rcu_dereference(ip6n->tnls_wc[0]);
121 	if (t && (t->dev->flags & IFF_UP))
122 		return t;
123 
124 	return NULL;
125 }
126 
127 /**
128  * vti6_tnl_bucket - get head of list matching given tunnel parameters
129  *   @ip6n: the private data for ip6_vti in the netns
130  *   @p: parameters containing tunnel end-points
131  *
132  * Description:
133  *   vti6_tnl_bucket() returns the head of the list matching the
134  *   &struct in6_addr entries laddr and raddr in @p.
135  *
136  * Return: head of IPv6 tunnel list
137  **/
138 static struct ip6_tnl __rcu **
vti6_tnl_bucket(struct vti6_net * ip6n,const struct __ip6_tnl_parm * p)139 vti6_tnl_bucket(struct vti6_net *ip6n, const struct __ip6_tnl_parm *p)
140 {
141 	const struct in6_addr *remote = &p->raddr;
142 	const struct in6_addr *local = &p->laddr;
143 	unsigned int h = 0;
144 	int prio = 0;
145 
146 	if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) {
147 		prio = 1;
148 		h = HASH(remote, local);
149 	}
150 	return &ip6n->tnls[prio][h];
151 }
152 
153 static void
vti6_tnl_link(struct vti6_net * ip6n,struct ip6_tnl * t)154 vti6_tnl_link(struct vti6_net *ip6n, struct ip6_tnl *t)
155 {
156 	struct ip6_tnl __rcu **tp = vti6_tnl_bucket(ip6n, &t->parms);
157 
158 	rcu_assign_pointer(t->next, rtnl_dereference(*tp));
159 	rcu_assign_pointer(*tp, t);
160 }
161 
162 static void
vti6_tnl_unlink(struct vti6_net * ip6n,struct ip6_tnl * t)163 vti6_tnl_unlink(struct vti6_net *ip6n, struct ip6_tnl *t)
164 {
165 	struct ip6_tnl __rcu **tp;
166 	struct ip6_tnl *iter;
167 
168 	for (tp = vti6_tnl_bucket(ip6n, &t->parms);
169 	     (iter = rtnl_dereference(*tp)) != NULL;
170 	     tp = &iter->next) {
171 		if (t == iter) {
172 			rcu_assign_pointer(*tp, t->next);
173 			break;
174 		}
175 	}
176 }
177 
vti6_tnl_create2(struct net_device * dev)178 static int vti6_tnl_create2(struct net_device *dev)
179 {
180 	struct ip6_tnl *t = netdev_priv(dev);
181 	struct vti6_net *ip6n = net_generic(t->net, vti6_net_id);
182 	int err;
183 
184 	dev->rtnl_link_ops = &vti6_link_ops;
185 	err = register_netdevice(dev);
186 	if (err < 0)
187 		goto out;
188 
189 	strcpy(t->parms.name, dev->name);
190 
191 	vti6_tnl_link(ip6n, t);
192 
193 	return 0;
194 
195 out:
196 	return err;
197 }
198 
vti6_tnl_create(struct net * net,struct __ip6_tnl_parm * p)199 static struct ip6_tnl *vti6_tnl_create(struct net *net, struct __ip6_tnl_parm *p)
200 {
201 	struct net_device *dev;
202 	struct ip6_tnl *t;
203 	char name[IFNAMSIZ];
204 	int err;
205 
206 	if (p->name[0]) {
207 		if (!dev_valid_name(p->name))
208 			goto failed;
209 		strscpy(name, p->name, IFNAMSIZ);
210 	} else {
211 		sprintf(name, "ip6_vti%%d");
212 	}
213 
214 	dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN, vti6_dev_setup);
215 	if (!dev)
216 		goto failed;
217 
218 	dev_net_set(dev, net);
219 
220 	t = netdev_priv(dev);
221 	t->parms = *p;
222 	t->net = dev_net(dev);
223 
224 	err = vti6_tnl_create2(dev);
225 	if (err < 0)
226 		goto failed_free;
227 
228 	return t;
229 
230 failed_free:
231 	free_netdev(dev);
232 failed:
233 	return NULL;
234 }
235 
236 /**
237  * vti6_locate - find or create tunnel matching given parameters
238  *   @net: network namespace
239  *   @p: tunnel parameters
240  *   @create: != 0 if allowed to create new tunnel if no match found
241  *
242  * Description:
243  *   vti6_locate() first tries to locate an existing tunnel
244  *   based on @parms. If this is unsuccessful, but @create is set a new
245  *   tunnel device is created and registered for use.
246  *
247  * Return:
248  *   matching tunnel or NULL
249  **/
vti6_locate(struct net * net,struct __ip6_tnl_parm * p,int create)250 static struct ip6_tnl *vti6_locate(struct net *net, struct __ip6_tnl_parm *p,
251 				   int create)
252 {
253 	const struct in6_addr *remote = &p->raddr;
254 	const struct in6_addr *local = &p->laddr;
255 	struct ip6_tnl __rcu **tp;
256 	struct ip6_tnl *t;
257 	struct vti6_net *ip6n = net_generic(net, vti6_net_id);
258 
259 	for (tp = vti6_tnl_bucket(ip6n, p);
260 	     (t = rtnl_dereference(*tp)) != NULL;
261 	     tp = &t->next) {
262 		if (ipv6_addr_equal(local, &t->parms.laddr) &&
263 		    ipv6_addr_equal(remote, &t->parms.raddr)) {
264 			if (create)
265 				return NULL;
266 
267 			return t;
268 		}
269 	}
270 	if (!create)
271 		return NULL;
272 	return vti6_tnl_create(net, p);
273 }
274 
275 /**
276  * vti6_dev_uninit - tunnel device uninitializer
277  *   @dev: the device to be destroyed
278  *
279  * Description:
280  *   vti6_dev_uninit() removes tunnel from its list
281  **/
vti6_dev_uninit(struct net_device * dev)282 static void vti6_dev_uninit(struct net_device *dev)
283 {
284 	struct ip6_tnl *t = netdev_priv(dev);
285 	struct vti6_net *ip6n = net_generic(t->net, vti6_net_id);
286 
287 	if (dev == ip6n->fb_tnl_dev)
288 		RCU_INIT_POINTER(ip6n->tnls_wc[0], NULL);
289 	else
290 		vti6_tnl_unlink(ip6n, t);
291 	netdev_put(dev, &t->dev_tracker);
292 }
293 
vti6_input_proto(struct sk_buff * skb,int nexthdr,__be32 spi,int encap_type)294 static int vti6_input_proto(struct sk_buff *skb, int nexthdr, __be32 spi,
295 			    int encap_type)
296 {
297 	struct ip6_tnl *t;
298 	const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
299 
300 	rcu_read_lock();
301 	t = vti6_tnl_lookup(dev_net(skb->dev), &ipv6h->saddr, &ipv6h->daddr);
302 	if (t) {
303 		if (t->parms.proto != IPPROTO_IPV6 && t->parms.proto != 0) {
304 			rcu_read_unlock();
305 			goto discard;
306 		}
307 
308 		if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
309 			rcu_read_unlock();
310 			goto discard;
311 		}
312 
313 		ipv6h = ipv6_hdr(skb);
314 		if (!ip6_tnl_rcv_ctl(t, &ipv6h->daddr, &ipv6h->saddr)) {
315 			DEV_STATS_INC(t->dev, rx_dropped);
316 			rcu_read_unlock();
317 			goto discard;
318 		}
319 
320 		rcu_read_unlock();
321 
322 		XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 = t;
323 		XFRM_SPI_SKB_CB(skb)->family = AF_INET6;
324 		XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct ipv6hdr, daddr);
325 		return xfrm_input(skb, nexthdr, spi, encap_type);
326 	}
327 	rcu_read_unlock();
328 	return -EINVAL;
329 discard:
330 	kfree_skb(skb);
331 	return 0;
332 }
333 
vti6_rcv(struct sk_buff * skb)334 static int vti6_rcv(struct sk_buff *skb)
335 {
336 	int nexthdr = skb_network_header(skb)[IP6CB(skb)->nhoff];
337 
338 	return vti6_input_proto(skb, nexthdr, 0, 0);
339 }
340 
vti6_rcv_cb(struct sk_buff * skb,int err)341 static int vti6_rcv_cb(struct sk_buff *skb, int err)
342 {
343 	unsigned short family;
344 	struct net_device *dev;
345 	struct xfrm_state *x;
346 	const struct xfrm_mode *inner_mode;
347 	struct ip6_tnl *t = XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6;
348 	u32 orig_mark = skb->mark;
349 	int ret;
350 
351 	if (!t)
352 		return 1;
353 
354 	dev = t->dev;
355 
356 	if (err) {
357 		DEV_STATS_INC(dev, rx_errors);
358 		DEV_STATS_INC(dev, rx_dropped);
359 
360 		return 0;
361 	}
362 
363 	x = xfrm_input_state(skb);
364 
365 	inner_mode = &x->inner_mode;
366 
367 	if (x->sel.family == AF_UNSPEC) {
368 		inner_mode = xfrm_ip2inner_mode(x, XFRM_MODE_SKB_CB(skb)->protocol);
369 		if (inner_mode == NULL) {
370 			XFRM_INC_STATS(dev_net(skb->dev),
371 				       LINUX_MIB_XFRMINSTATEMODEERROR);
372 			return -EINVAL;
373 		}
374 	}
375 
376 	family = inner_mode->family;
377 
378 	skb->mark = be32_to_cpu(t->parms.i_key);
379 	ret = xfrm_policy_check(NULL, XFRM_POLICY_IN, skb, family);
380 	skb->mark = orig_mark;
381 
382 	if (!ret)
383 		return -EPERM;
384 
385 	skb_scrub_packet(skb, !net_eq(t->net, dev_net(skb->dev)));
386 	skb->dev = dev;
387 	dev_sw_netstats_rx_add(dev, skb->len);
388 
389 	return 0;
390 }
391 
392 /**
393  * vti6_addr_conflict - compare packet addresses to tunnel's own
394  *   @t: the outgoing tunnel device
395  *   @hdr: IPv6 header from the incoming packet
396  *
397  * Description:
398  *   Avoid trivial tunneling loop by checking that tunnel exit-point
399  *   doesn't match source of incoming packet.
400  *
401  * Return:
402  *   1 if conflict,
403  *   0 else
404  **/
405 static inline bool
vti6_addr_conflict(const struct ip6_tnl * t,const struct ipv6hdr * hdr)406 vti6_addr_conflict(const struct ip6_tnl *t, const struct ipv6hdr *hdr)
407 {
408 	return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
409 }
410 
vti6_state_check(const struct xfrm_state * x,const struct in6_addr * dst,const struct in6_addr * src)411 static bool vti6_state_check(const struct xfrm_state *x,
412 			     const struct in6_addr *dst,
413 			     const struct in6_addr *src)
414 {
415 	xfrm_address_t *daddr = (xfrm_address_t *)dst;
416 	xfrm_address_t *saddr = (xfrm_address_t *)src;
417 
418 	/* if there is no transform then this tunnel is not functional.
419 	 * Or if the xfrm is not mode tunnel.
420 	 */
421 	if (!x || x->props.mode != XFRM_MODE_TUNNEL ||
422 	    x->props.family != AF_INET6)
423 		return false;
424 
425 	if (ipv6_addr_any(dst))
426 		return xfrm_addr_equal(saddr, &x->props.saddr, AF_INET6);
427 
428 	if (!xfrm_state_addr_check(x, daddr, saddr, AF_INET6))
429 		return false;
430 
431 	return true;
432 }
433 
434 /**
435  * vti6_xmit - send a packet
436  *   @skb: the outgoing socket buffer
437  *   @dev: the outgoing tunnel device
438  *   @fl: the flow informations for the xfrm_lookup
439  **/
440 static int
vti6_xmit(struct sk_buff * skb,struct net_device * dev,struct flowi * fl)441 vti6_xmit(struct sk_buff *skb, struct net_device *dev, struct flowi *fl)
442 {
443 	struct ip6_tnl *t = netdev_priv(dev);
444 	struct dst_entry *dst = skb_dst(skb);
445 	struct net_device *tdev;
446 	struct xfrm_state *x;
447 	int pkt_len = skb->len;
448 	int err = -1;
449 	int mtu;
450 
451 	if (!dst) {
452 		switch (skb->protocol) {
453 		case htons(ETH_P_IP): {
454 			struct rtable *rt;
455 
456 			fl->u.ip4.flowi4_oif = dev->ifindex;
457 			fl->u.ip4.flowi4_flags |= FLOWI_FLAG_ANYSRC;
458 			rt = __ip_route_output_key(dev_net(dev), &fl->u.ip4);
459 			if (IS_ERR(rt))
460 				goto tx_err_link_failure;
461 			dst = &rt->dst;
462 			skb_dst_set(skb, dst);
463 			break;
464 		}
465 		case htons(ETH_P_IPV6):
466 			fl->u.ip6.flowi6_oif = dev->ifindex;
467 			fl->u.ip6.flowi6_flags |= FLOWI_FLAG_ANYSRC;
468 			dst = ip6_route_output(dev_net(dev), NULL, &fl->u.ip6);
469 			if (dst->error) {
470 				dst_release(dst);
471 				dst = NULL;
472 				goto tx_err_link_failure;
473 			}
474 			skb_dst_set(skb, dst);
475 			break;
476 		default:
477 			goto tx_err_link_failure;
478 		}
479 	}
480 
481 	dst_hold(dst);
482 	dst = xfrm_lookup_route(t->net, dst, fl, NULL, 0);
483 	if (IS_ERR(dst)) {
484 		err = PTR_ERR(dst);
485 		dst = NULL;
486 		goto tx_err_link_failure;
487 	}
488 
489 	if (dst->flags & DST_XFRM_QUEUE)
490 		goto xmit;
491 
492 	x = dst->xfrm;
493 	if (!vti6_state_check(x, &t->parms.raddr, &t->parms.laddr))
494 		goto tx_err_link_failure;
495 
496 	if (!ip6_tnl_xmit_ctl(t, (const struct in6_addr *)&x->props.saddr,
497 			      (const struct in6_addr *)&x->id.daddr))
498 		goto tx_err_link_failure;
499 
500 	tdev = dst_dev(dst);
501 
502 	if (tdev == dev) {
503 		DEV_STATS_INC(dev, collisions);
504 		net_warn_ratelimited("%s: Local routing loop detected!\n",
505 				     t->parms.name);
506 		goto tx_err_dst_release;
507 	}
508 
509 	mtu = dst_mtu(dst);
510 	if (skb->len > mtu) {
511 		skb_dst_update_pmtu_no_confirm(skb, mtu);
512 
513 		if (skb->protocol == htons(ETH_P_IPV6)) {
514 			if (mtu < IPV6_MIN_MTU)
515 				mtu = IPV6_MIN_MTU;
516 
517 			icmpv6_ndo_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
518 		} else {
519 			if (!(ip_hdr(skb)->frag_off & htons(IP_DF)))
520 				goto xmit;
521 			icmp_ndo_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
522 				      htonl(mtu));
523 		}
524 
525 		err = -EMSGSIZE;
526 		goto tx_err_dst_release;
527 	}
528 
529 xmit:
530 	skb_scrub_packet(skb, !net_eq(t->net, dev_net(dev)));
531 	skb_dst_set(skb, dst);
532 	skb->dev = dst_dev(dst);
533 
534 	err = dst_output(t->net, skb->sk, skb);
535 	if (net_xmit_eval(err) == 0)
536 		err = pkt_len;
537 	iptunnel_xmit_stats(dev, err);
538 
539 	return 0;
540 tx_err_link_failure:
541 	DEV_STATS_INC(dev, tx_carrier_errors);
542 	dst_link_failure(skb);
543 tx_err_dst_release:
544 	dst_release(dst);
545 	return err;
546 }
547 
548 static netdev_tx_t
vti6_tnl_xmit(struct sk_buff * skb,struct net_device * dev)549 vti6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
550 {
551 	struct ip6_tnl *t = netdev_priv(dev);
552 	struct flowi fl;
553 	int ret;
554 
555 	if (!pskb_inet_may_pull(skb))
556 		goto tx_err;
557 
558 	memset(&fl, 0, sizeof(fl));
559 
560 	switch (skb->protocol) {
561 	case htons(ETH_P_IPV6):
562 		if ((t->parms.proto != IPPROTO_IPV6 && t->parms.proto != 0) ||
563 		    vti6_addr_conflict(t, ipv6_hdr(skb)))
564 			goto tx_err;
565 
566 		memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
567 		xfrm_decode_session(dev_net(dev), skb, &fl, AF_INET6);
568 		break;
569 	case htons(ETH_P_IP):
570 		memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
571 		xfrm_decode_session(dev_net(dev), skb, &fl, AF_INET);
572 		break;
573 	default:
574 		goto tx_err;
575 	}
576 
577 	/* override mark with tunnel output key */
578 	fl.flowi_mark = be32_to_cpu(t->parms.o_key);
579 
580 	ret = vti6_xmit(skb, dev, &fl);
581 	if (ret < 0)
582 		goto tx_err;
583 
584 	return NETDEV_TX_OK;
585 
586 tx_err:
587 	DEV_STATS_INC(dev, tx_errors);
588 	DEV_STATS_INC(dev, tx_dropped);
589 	kfree_skb(skb);
590 	return NETDEV_TX_OK;
591 }
592 
vti6_err(struct sk_buff * skb,struct inet6_skb_parm * opt,u8 type,u8 code,int offset,__be32 info)593 static int vti6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
594 		    u8 type, u8 code, int offset, __be32 info)
595 {
596 	__be32 spi;
597 	__u32 mark;
598 	struct xfrm_state *x;
599 	struct ip6_tnl *t;
600 	struct ip_esp_hdr *esph;
601 	struct ip_auth_hdr *ah;
602 	struct ip_comp_hdr *ipch;
603 	struct net *net = dev_net(skb->dev);
604 	const struct ipv6hdr *iph = (const struct ipv6hdr *)skb->data;
605 	int protocol = iph->nexthdr;
606 
607 	t = vti6_tnl_lookup(dev_net(skb->dev), &iph->daddr, &iph->saddr);
608 	if (!t)
609 		return -1;
610 
611 	mark = be32_to_cpu(t->parms.o_key);
612 
613 	switch (protocol) {
614 	case IPPROTO_ESP:
615 		esph = (struct ip_esp_hdr *)(skb->data + offset);
616 		spi = esph->spi;
617 		break;
618 	case IPPROTO_AH:
619 		ah = (struct ip_auth_hdr *)(skb->data + offset);
620 		spi = ah->spi;
621 		break;
622 	case IPPROTO_COMP:
623 		ipch = (struct ip_comp_hdr *)(skb->data + offset);
624 		spi = htonl(ntohs(ipch->cpi));
625 		break;
626 	default:
627 		return 0;
628 	}
629 
630 	if (type != ICMPV6_PKT_TOOBIG &&
631 	    type != NDISC_REDIRECT)
632 		return 0;
633 
634 	x = xfrm_state_lookup(net, mark, (const xfrm_address_t *)&iph->daddr,
635 			      spi, protocol, AF_INET6);
636 	if (!x)
637 		return 0;
638 
639 	if (type == NDISC_REDIRECT)
640 		ip6_redirect(skb, net, skb->dev->ifindex, 0,
641 			     sock_net_uid(net, NULL));
642 	else
643 		ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL));
644 	xfrm_state_put(x);
645 
646 	return 0;
647 }
648 
vti6_link_config(struct ip6_tnl * t,bool keep_mtu)649 static void vti6_link_config(struct ip6_tnl *t, bool keep_mtu)
650 {
651 	struct net_device *dev = t->dev;
652 	struct __ip6_tnl_parm *p = &t->parms;
653 	struct net_device *tdev = NULL;
654 	int mtu;
655 
656 	__dev_addr_set(dev, &p->laddr, sizeof(struct in6_addr));
657 	memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
658 
659 	p->flags &= ~(IP6_TNL_F_CAP_XMIT | IP6_TNL_F_CAP_RCV |
660 		      IP6_TNL_F_CAP_PER_PACKET);
661 	p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
662 
663 	if (p->flags & IP6_TNL_F_CAP_XMIT && p->flags & IP6_TNL_F_CAP_RCV)
664 		dev->flags |= IFF_POINTOPOINT;
665 	else
666 		dev->flags &= ~IFF_POINTOPOINT;
667 
668 	if (keep_mtu && dev->mtu) {
669 		WRITE_ONCE(dev->mtu,
670 			   clamp(dev->mtu, dev->min_mtu, dev->max_mtu));
671 		return;
672 	}
673 
674 	if (p->flags & IP6_TNL_F_CAP_XMIT) {
675 		int strict = (ipv6_addr_type(&p->raddr) &
676 			      (IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL));
677 		struct rt6_info *rt = rt6_lookup(t->net,
678 						 &p->raddr, &p->laddr,
679 						 p->link, NULL, strict);
680 
681 		if (rt)
682 			tdev = rt->dst.dev;
683 		ip6_rt_put(rt);
684 	}
685 
686 	if (!tdev && p->link)
687 		tdev = __dev_get_by_index(t->net, p->link);
688 
689 	if (tdev)
690 		mtu = tdev->mtu - sizeof(struct ipv6hdr);
691 	else
692 		mtu = ETH_DATA_LEN - LL_MAX_HEADER - sizeof(struct ipv6hdr);
693 
694 	dev->mtu = max_t(int, mtu, IPV4_MIN_MTU);
695 }
696 
697 /**
698  * vti6_tnl_change - update the tunnel parameters
699  *   @t: tunnel to be changed
700  *   @p: tunnel configuration parameters
701  *   @keep_mtu: MTU was set from userspace, don't re-compute it
702  *
703  * Description:
704  *   vti6_tnl_change() updates the tunnel parameters
705  **/
706 static int
vti6_tnl_change(struct ip6_tnl * t,const struct __ip6_tnl_parm * p,bool keep_mtu)707 vti6_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p,
708 		bool keep_mtu)
709 {
710 	t->parms.laddr = p->laddr;
711 	t->parms.raddr = p->raddr;
712 	t->parms.link = p->link;
713 	t->parms.i_key = p->i_key;
714 	t->parms.o_key = p->o_key;
715 	t->parms.proto = p->proto;
716 	t->parms.fwmark = p->fwmark;
717 	dst_cache_reset(&t->dst_cache);
718 	vti6_link_config(t, keep_mtu);
719 	return 0;
720 }
721 
vti6_update(struct ip6_tnl * t,struct __ip6_tnl_parm * p,bool keep_mtu)722 static int vti6_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p,
723 		       bool keep_mtu)
724 {
725 	struct net *net = t->net;
726 	struct vti6_net *ip6n;
727 	int err;
728 
729 	ip6n = net_generic(net, vti6_net_id);
730 	vti6_tnl_unlink(ip6n, t);
731 	synchronize_net();
732 	err = vti6_tnl_change(t, p, keep_mtu);
733 	vti6_tnl_link(ip6n, t);
734 	netdev_state_change(t->dev);
735 	return err;
736 }
737 
738 static void
vti6_parm_from_user(struct __ip6_tnl_parm * p,const struct ip6_tnl_parm2 * u)739 vti6_parm_from_user(struct __ip6_tnl_parm *p, const struct ip6_tnl_parm2 *u)
740 {
741 	p->laddr = u->laddr;
742 	p->raddr = u->raddr;
743 	p->link = u->link;
744 	p->i_key = u->i_key;
745 	p->o_key = u->o_key;
746 	p->proto = u->proto;
747 
748 	memcpy(p->name, u->name, sizeof(u->name));
749 }
750 
751 static void
vti6_parm_to_user(struct ip6_tnl_parm2 * u,const struct __ip6_tnl_parm * p)752 vti6_parm_to_user(struct ip6_tnl_parm2 *u, const struct __ip6_tnl_parm *p)
753 {
754 	u->laddr = p->laddr;
755 	u->raddr = p->raddr;
756 	u->link = p->link;
757 	u->i_key = p->i_key;
758 	u->o_key = p->o_key;
759 	if (u->i_key)
760 		u->i_flags |= GRE_KEY;
761 	if (u->o_key)
762 		u->o_flags |= GRE_KEY;
763 	u->proto = p->proto;
764 
765 	memcpy(u->name, p->name, sizeof(u->name));
766 }
767 
768 /**
769  * vti6_siocdevprivate - configure vti6 tunnels from userspace
770  *   @dev: virtual device associated with tunnel
771  *   @ifr: unused
772  *   @data: parameters passed from userspace
773  *   @cmd: command to be performed
774  *
775  * Description:
776  *   vti6_siocdevprivate() is used for managing vti6 tunnels
777  *   from userspace.
778  *
779  *   The possible commands are the following:
780  *     %SIOCGETTUNNEL: get tunnel parameters for device
781  *     %SIOCADDTUNNEL: add tunnel matching given tunnel parameters
782  *     %SIOCCHGTUNNEL: change tunnel parameters to those given
783  *     %SIOCDELTUNNEL: delete tunnel
784  *
785  *   The fallback device "ip6_vti0", created during module
786  *   initialization, can be used for creating other tunnel devices.
787  *
788  * Return:
789  *   0 on success,
790  *   %-EFAULT if unable to copy data to or from userspace,
791  *   %-EPERM if current process hasn't %CAP_NET_ADMIN set
792  *   %-EINVAL if passed tunnel parameters are invalid,
793  *   %-EEXIST if changing a tunnel's parameters would cause a conflict
794  *   %-ENODEV if attempting to change or delete a nonexisting device
795  **/
796 static int
vti6_siocdevprivate(struct net_device * dev,struct ifreq * ifr,void __user * data,int cmd)797 vti6_siocdevprivate(struct net_device *dev, struct ifreq *ifr, void __user *data, int cmd)
798 {
799 	int err = 0;
800 	struct ip6_tnl_parm2 p;
801 	struct __ip6_tnl_parm p1;
802 	struct ip6_tnl *t = NULL;
803 	struct net *net = dev_net(dev);
804 	struct vti6_net *ip6n = net_generic(net, vti6_net_id);
805 
806 	memset(&p1, 0, sizeof(p1));
807 
808 	switch (cmd) {
809 	case SIOCGETTUNNEL:
810 		if (dev == ip6n->fb_tnl_dev) {
811 			if (copy_from_user(&p, data, sizeof(p))) {
812 				err = -EFAULT;
813 				break;
814 			}
815 			vti6_parm_from_user(&p1, &p);
816 			t = vti6_locate(net, &p1, 0);
817 		} else {
818 			memset(&p, 0, sizeof(p));
819 		}
820 		if (!t)
821 			t = netdev_priv(dev);
822 		vti6_parm_to_user(&p, &t->parms);
823 		if (copy_to_user(data, &p, sizeof(p)))
824 			err = -EFAULT;
825 		break;
826 	case SIOCADDTUNNEL:
827 	case SIOCCHGTUNNEL:
828 		err = -EPERM;
829 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
830 			break;
831 		err = -EFAULT;
832 		if (copy_from_user(&p, data, sizeof(p)))
833 			break;
834 		err = -EINVAL;
835 		if (p.proto != IPPROTO_IPV6  && p.proto != 0)
836 			break;
837 		vti6_parm_from_user(&p1, &p);
838 		if (dev != ip6n->fb_tnl_dev && cmd == SIOCCHGTUNNEL) {
839 			struct ip6_tnl *self = netdev_priv(dev);
840 
841 			err = -EPERM;
842 			if (!ns_capable(self->net->user_ns, CAP_NET_ADMIN))
843 				break;
844 			t = vti6_locate(self->net, &p1, false);
845 			if (t) {
846 				if (t->dev != dev) {
847 					err = -EEXIST;
848 					break;
849 				}
850 			} else
851 				t = self;
852 
853 			err = vti6_update(t, &p1, false);
854 		} else {
855 			t = vti6_locate(net, &p1, cmd == SIOCADDTUNNEL);
856 		}
857 		if (t) {
858 			err = 0;
859 			vti6_parm_to_user(&p, &t->parms);
860 			if (copy_to_user(data, &p, sizeof(p)))
861 				err = -EFAULT;
862 
863 		} else
864 			err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
865 		break;
866 	case SIOCDELTUNNEL:
867 		err = -EPERM;
868 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
869 			break;
870 
871 		if (dev == ip6n->fb_tnl_dev) {
872 			err = -EFAULT;
873 			if (copy_from_user(&p, data, sizeof(p)))
874 				break;
875 			err = -ENOENT;
876 			vti6_parm_from_user(&p1, &p);
877 			t = vti6_locate(net, &p1, 0);
878 			if (!t)
879 				break;
880 			err = -EPERM;
881 			if (t->dev == ip6n->fb_tnl_dev)
882 				break;
883 			dev = t->dev;
884 		}
885 		err = 0;
886 		unregister_netdevice(dev);
887 		break;
888 	default:
889 		err = -EINVAL;
890 	}
891 	return err;
892 }
893 
894 static const struct net_device_ops vti6_netdev_ops = {
895 	.ndo_init	= vti6_dev_init,
896 	.ndo_uninit	= vti6_dev_uninit,
897 	.ndo_start_xmit = vti6_tnl_xmit,
898 	.ndo_siocdevprivate = vti6_siocdevprivate,
899 	.ndo_get_iflink = ip6_tnl_get_iflink,
900 };
901 
902 /**
903  * vti6_dev_setup - setup virtual tunnel device
904  *   @dev: virtual device associated with tunnel
905  *
906  * Description:
907  *   Initialize function pointers and device parameters
908  **/
vti6_dev_setup(struct net_device * dev)909 static void vti6_dev_setup(struct net_device *dev)
910 {
911 	dev->netdev_ops = &vti6_netdev_ops;
912 	dev->header_ops = &ip_tunnel_header_ops;
913 	dev->needs_free_netdev = true;
914 
915 	dev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS;
916 	dev->type = ARPHRD_TUNNEL6;
917 	dev->min_mtu = IPV4_MIN_MTU;
918 	dev->max_mtu = IP_MAX_MTU - sizeof(struct ipv6hdr);
919 	dev->flags |= IFF_NOARP;
920 	dev->addr_len = sizeof(struct in6_addr);
921 	netif_keep_dst(dev);
922 	/* This perm addr will be used as interface identifier by IPv6 */
923 	dev->addr_assign_type = NET_ADDR_RANDOM;
924 	eth_random_addr(dev->perm_addr);
925 }
926 
927 /**
928  * vti6_dev_init_gen - general initializer for all tunnel devices
929  *   @dev: virtual device associated with tunnel
930  **/
vti6_dev_init_gen(struct net_device * dev)931 static inline int vti6_dev_init_gen(struct net_device *dev)
932 {
933 	struct ip6_tnl *t = netdev_priv(dev);
934 
935 	t->dev = dev;
936 	netdev_hold(dev, &t->dev_tracker, GFP_KERNEL);
937 	netdev_lockdep_set_classes(dev);
938 	return 0;
939 }
940 
941 /**
942  * vti6_dev_init - initializer for all non fallback tunnel devices
943  *   @dev: virtual device associated with tunnel
944  **/
vti6_dev_init(struct net_device * dev)945 static int vti6_dev_init(struct net_device *dev)
946 {
947 	struct ip6_tnl *t = netdev_priv(dev);
948 	int err = vti6_dev_init_gen(dev);
949 
950 	if (err)
951 		return err;
952 	vti6_link_config(t, true);
953 	return 0;
954 }
955 
956 /**
957  * vti6_fb_tnl_dev_init - initializer for fallback tunnel device
958  *   @dev: fallback device
959  *
960  * Return: 0
961  **/
vti6_fb_tnl_dev_init(struct net_device * dev)962 static int __net_init vti6_fb_tnl_dev_init(struct net_device *dev)
963 {
964 	struct ip6_tnl *t = netdev_priv(dev);
965 	struct net *net = dev_net(dev);
966 	struct vti6_net *ip6n = net_generic(net, vti6_net_id);
967 
968 	t->net = net;
969 	t->parms.proto = IPPROTO_IPV6;
970 
971 	rcu_assign_pointer(ip6n->tnls_wc[0], t);
972 	return 0;
973 }
974 
vti6_validate(struct nlattr * tb[],struct nlattr * data[],struct netlink_ext_ack * extack)975 static int vti6_validate(struct nlattr *tb[], struct nlattr *data[],
976 			 struct netlink_ext_ack *extack)
977 {
978 	return 0;
979 }
980 
vti6_netlink_parms(struct nlattr * data[],struct __ip6_tnl_parm * parms)981 static void vti6_netlink_parms(struct nlattr *data[],
982 			       struct __ip6_tnl_parm *parms)
983 {
984 	memset(parms, 0, sizeof(*parms));
985 
986 	if (!data)
987 		return;
988 
989 	if (data[IFLA_VTI_LINK])
990 		parms->link = nla_get_u32(data[IFLA_VTI_LINK]);
991 
992 	if (data[IFLA_VTI_LOCAL])
993 		parms->laddr = nla_get_in6_addr(data[IFLA_VTI_LOCAL]);
994 
995 	if (data[IFLA_VTI_REMOTE])
996 		parms->raddr = nla_get_in6_addr(data[IFLA_VTI_REMOTE]);
997 
998 	if (data[IFLA_VTI_IKEY])
999 		parms->i_key = nla_get_be32(data[IFLA_VTI_IKEY]);
1000 
1001 	if (data[IFLA_VTI_OKEY])
1002 		parms->o_key = nla_get_be32(data[IFLA_VTI_OKEY]);
1003 
1004 	if (data[IFLA_VTI_FWMARK])
1005 		parms->fwmark = nla_get_u32(data[IFLA_VTI_FWMARK]);
1006 }
1007 
vti6_newlink(struct net_device * dev,struct rtnl_newlink_params * params,struct netlink_ext_ack * extack)1008 static int vti6_newlink(struct net_device *dev,
1009 			struct rtnl_newlink_params *params,
1010 			struct netlink_ext_ack *extack)
1011 {
1012 	struct nlattr **data = params->data;
1013 	struct ip6_tnl *nt;
1014 	struct net *net;
1015 
1016 	net = params->link_net ? : dev_net(dev);
1017 	nt = netdev_priv(dev);
1018 	vti6_netlink_parms(data, &nt->parms);
1019 
1020 	nt->parms.proto = IPPROTO_IPV6;
1021 	nt->net = net;
1022 
1023 	if (vti6_locate(net, &nt->parms, 0))
1024 		return -EEXIST;
1025 
1026 	return vti6_tnl_create2(dev);
1027 }
1028 
vti6_dellink(struct net_device * dev,struct list_head * head)1029 static void vti6_dellink(struct net_device *dev, struct list_head *head)
1030 {
1031 	struct net *net = dev_net(dev);
1032 	struct vti6_net *ip6n = net_generic(net, vti6_net_id);
1033 
1034 	if (dev != ip6n->fb_tnl_dev)
1035 		unregister_netdevice_queue(dev, head);
1036 }
1037 
vti6_changelink(struct net_device * dev,struct nlattr * tb[],struct nlattr * data[],struct netlink_ext_ack * extack)1038 static int vti6_changelink(struct net_device *dev, struct nlattr *tb[],
1039 			   struct nlattr *data[],
1040 			   struct netlink_ext_ack *extack)
1041 {
1042 	struct ip6_tnl *t = netdev_priv(dev);
1043 	struct net *net = t->net;
1044 	struct __ip6_tnl_parm p;
1045 	struct vti6_net *ip6n;
1046 
1047 	ip6n = net_generic(net, vti6_net_id);
1048 	if (dev == ip6n->fb_tnl_dev)
1049 		return -EINVAL;
1050 
1051 	vti6_netlink_parms(data, &p);
1052 
1053 	t = vti6_locate(net, &p, 0);
1054 
1055 	if (t) {
1056 		if (t->dev != dev)
1057 			return -EEXIST;
1058 	} else
1059 		t = netdev_priv(dev);
1060 
1061 	return vti6_update(t, &p, tb && tb[IFLA_MTU]);
1062 }
1063 
vti6_get_size(const struct net_device * dev)1064 static size_t vti6_get_size(const struct net_device *dev)
1065 {
1066 	return
1067 		/* IFLA_VTI_LINK */
1068 		nla_total_size(4) +
1069 		/* IFLA_VTI_LOCAL */
1070 		nla_total_size(sizeof(struct in6_addr)) +
1071 		/* IFLA_VTI_REMOTE */
1072 		nla_total_size(sizeof(struct in6_addr)) +
1073 		/* IFLA_VTI_IKEY */
1074 		nla_total_size(4) +
1075 		/* IFLA_VTI_OKEY */
1076 		nla_total_size(4) +
1077 		/* IFLA_VTI_FWMARK */
1078 		nla_total_size(4) +
1079 		0;
1080 }
1081 
vti6_fill_info(struct sk_buff * skb,const struct net_device * dev)1082 static int vti6_fill_info(struct sk_buff *skb, const struct net_device *dev)
1083 {
1084 	struct ip6_tnl *tunnel = netdev_priv(dev);
1085 	struct __ip6_tnl_parm *parm = &tunnel->parms;
1086 
1087 	if (nla_put_u32(skb, IFLA_VTI_LINK, parm->link) ||
1088 	    nla_put_in6_addr(skb, IFLA_VTI_LOCAL, &parm->laddr) ||
1089 	    nla_put_in6_addr(skb, IFLA_VTI_REMOTE, &parm->raddr) ||
1090 	    nla_put_be32(skb, IFLA_VTI_IKEY, parm->i_key) ||
1091 	    nla_put_be32(skb, IFLA_VTI_OKEY, parm->o_key) ||
1092 	    nla_put_u32(skb, IFLA_VTI_FWMARK, parm->fwmark))
1093 		goto nla_put_failure;
1094 	return 0;
1095 
1096 nla_put_failure:
1097 	return -EMSGSIZE;
1098 }
1099 
1100 static const struct nla_policy vti6_policy[IFLA_VTI_MAX + 1] = {
1101 	[IFLA_VTI_LINK]		= { .type = NLA_U32 },
1102 	[IFLA_VTI_LOCAL]	= { .len = sizeof(struct in6_addr) },
1103 	[IFLA_VTI_REMOTE]	= { .len = sizeof(struct in6_addr) },
1104 	[IFLA_VTI_IKEY]		= { .type = NLA_U32 },
1105 	[IFLA_VTI_OKEY]		= { .type = NLA_U32 },
1106 	[IFLA_VTI_FWMARK]	= { .type = NLA_U32 },
1107 };
1108 
1109 static struct rtnl_link_ops vti6_link_ops __read_mostly = {
1110 	.kind		= "vti6",
1111 	.maxtype	= IFLA_VTI_MAX,
1112 	.policy		= vti6_policy,
1113 	.priv_size	= sizeof(struct ip6_tnl),
1114 	.setup		= vti6_dev_setup,
1115 	.validate	= vti6_validate,
1116 	.newlink	= vti6_newlink,
1117 	.dellink	= vti6_dellink,
1118 	.changelink	= vti6_changelink,
1119 	.get_size	= vti6_get_size,
1120 	.fill_info	= vti6_fill_info,
1121 	.get_link_net	= ip6_tnl_get_link_net,
1122 };
1123 
vti6_exit_rtnl_net(struct net * net,struct list_head * list)1124 static void __net_exit vti6_exit_rtnl_net(struct net *net, struct list_head *list)
1125 {
1126 	struct vti6_net *ip6n = net_generic(net, vti6_net_id);
1127 	struct ip6_tnl *t;
1128 	int h;
1129 
1130 	for (h = 0; h < IP6_VTI_HASH_SIZE; h++) {
1131 		t = rtnl_net_dereference(net, ip6n->tnls_r_l[h]);
1132 		while (t) {
1133 			unregister_netdevice_queue(t->dev, list);
1134 			t = rtnl_net_dereference(net, t->next);
1135 		}
1136 	}
1137 
1138 	t = rtnl_net_dereference(net, ip6n->tnls_wc[0]);
1139 	if (t)
1140 		unregister_netdevice_queue(t->dev, list);
1141 }
1142 
vti6_init_net(struct net * net)1143 static int __net_init vti6_init_net(struct net *net)
1144 {
1145 	struct vti6_net *ip6n = net_generic(net, vti6_net_id);
1146 	struct ip6_tnl *t = NULL;
1147 	int err;
1148 
1149 	ip6n->tnls[0] = ip6n->tnls_wc;
1150 	ip6n->tnls[1] = ip6n->tnls_r_l;
1151 
1152 	if (!net_has_fallback_tunnels(net))
1153 		return 0;
1154 	err = -ENOMEM;
1155 	ip6n->fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6_vti0",
1156 					NET_NAME_UNKNOWN, vti6_dev_setup);
1157 
1158 	if (!ip6n->fb_tnl_dev)
1159 		goto err_alloc_dev;
1160 	dev_net_set(ip6n->fb_tnl_dev, net);
1161 	ip6n->fb_tnl_dev->rtnl_link_ops = &vti6_link_ops;
1162 
1163 	err = vti6_fb_tnl_dev_init(ip6n->fb_tnl_dev);
1164 	if (err < 0)
1165 		goto err_register;
1166 
1167 	err = register_netdev(ip6n->fb_tnl_dev);
1168 	if (err < 0)
1169 		goto err_register;
1170 
1171 	t = netdev_priv(ip6n->fb_tnl_dev);
1172 
1173 	strcpy(t->parms.name, ip6n->fb_tnl_dev->name);
1174 	return 0;
1175 
1176 err_register:
1177 	free_netdev(ip6n->fb_tnl_dev);
1178 err_alloc_dev:
1179 	return err;
1180 }
1181 
1182 static struct pernet_operations vti6_net_ops = {
1183 	.init = vti6_init_net,
1184 	.exit_rtnl = vti6_exit_rtnl_net,
1185 	.id   = &vti6_net_id,
1186 	.size = sizeof(struct vti6_net),
1187 };
1188 
1189 static struct xfrm6_protocol vti_esp6_protocol __read_mostly = {
1190 	.handler	=	vti6_rcv,
1191 	.input_handler	=	vti6_input_proto,
1192 	.cb_handler	=	vti6_rcv_cb,
1193 	.err_handler	=	vti6_err,
1194 	.priority	=	100,
1195 };
1196 
1197 static struct xfrm6_protocol vti_ah6_protocol __read_mostly = {
1198 	.handler	=	vti6_rcv,
1199 	.input_handler	=	vti6_input_proto,
1200 	.cb_handler	=	vti6_rcv_cb,
1201 	.err_handler	=	vti6_err,
1202 	.priority	=	100,
1203 };
1204 
1205 static struct xfrm6_protocol vti_ipcomp6_protocol __read_mostly = {
1206 	.handler	=	vti6_rcv,
1207 	.input_handler	=	vti6_input_proto,
1208 	.cb_handler	=	vti6_rcv_cb,
1209 	.err_handler	=	vti6_err,
1210 	.priority	=	100,
1211 };
1212 
1213 #if IS_REACHABLE(CONFIG_INET6_XFRM_TUNNEL)
vti6_rcv_tunnel(struct sk_buff * skb)1214 static int vti6_rcv_tunnel(struct sk_buff *skb)
1215 {
1216 	const xfrm_address_t *saddr;
1217 	__be32 spi;
1218 
1219 	saddr = (const xfrm_address_t *)&ipv6_hdr(skb)->saddr;
1220 	spi = xfrm6_tunnel_spi_lookup(dev_net(skb->dev), saddr);
1221 
1222 	return vti6_input_proto(skb, IPPROTO_IPV6, spi, 0);
1223 }
1224 
1225 static struct xfrm6_tunnel vti_ipv6_handler __read_mostly = {
1226 	.handler	=	vti6_rcv_tunnel,
1227 	.cb_handler	=	vti6_rcv_cb,
1228 	.err_handler	=	vti6_err,
1229 	.priority	=	0,
1230 };
1231 
1232 static struct xfrm6_tunnel vti_ip6ip_handler __read_mostly = {
1233 	.handler	=	vti6_rcv_tunnel,
1234 	.cb_handler	=	vti6_rcv_cb,
1235 	.err_handler	=	vti6_err,
1236 	.priority	=	0,
1237 };
1238 #endif
1239 
1240 /**
1241  * vti6_tunnel_init - register protocol and reserve needed resources
1242  *
1243  * Return: 0 on success
1244  **/
vti6_tunnel_init(void)1245 static int __init vti6_tunnel_init(void)
1246 {
1247 	const char *msg;
1248 	int err;
1249 
1250 	msg = "tunnel device";
1251 	err = register_pernet_device(&vti6_net_ops);
1252 	if (err < 0)
1253 		goto pernet_dev_failed;
1254 
1255 	msg = "tunnel protocols";
1256 	err = xfrm6_protocol_register(&vti_esp6_protocol, IPPROTO_ESP);
1257 	if (err < 0)
1258 		goto xfrm_proto_esp_failed;
1259 	err = xfrm6_protocol_register(&vti_ah6_protocol, IPPROTO_AH);
1260 	if (err < 0)
1261 		goto xfrm_proto_ah_failed;
1262 	err = xfrm6_protocol_register(&vti_ipcomp6_protocol, IPPROTO_COMP);
1263 	if (err < 0)
1264 		goto xfrm_proto_comp_failed;
1265 #if IS_REACHABLE(CONFIG_INET6_XFRM_TUNNEL)
1266 	msg = "ipv6 tunnel";
1267 	err = xfrm6_tunnel_register(&vti_ipv6_handler, AF_INET6);
1268 	if (err < 0)
1269 		goto vti_tunnel_ipv6_failed;
1270 	err = xfrm6_tunnel_register(&vti_ip6ip_handler, AF_INET);
1271 	if (err < 0)
1272 		goto vti_tunnel_ip6ip_failed;
1273 #endif
1274 
1275 	msg = "netlink interface";
1276 	err = rtnl_link_register(&vti6_link_ops);
1277 	if (err < 0)
1278 		goto rtnl_link_failed;
1279 
1280 	return 0;
1281 
1282 rtnl_link_failed:
1283 #if IS_REACHABLE(CONFIG_INET6_XFRM_TUNNEL)
1284 	err = xfrm6_tunnel_deregister(&vti_ip6ip_handler, AF_INET);
1285 vti_tunnel_ip6ip_failed:
1286 	err = xfrm6_tunnel_deregister(&vti_ipv6_handler, AF_INET6);
1287 vti_tunnel_ipv6_failed:
1288 #endif
1289 	xfrm6_protocol_deregister(&vti_ipcomp6_protocol, IPPROTO_COMP);
1290 xfrm_proto_comp_failed:
1291 	xfrm6_protocol_deregister(&vti_ah6_protocol, IPPROTO_AH);
1292 xfrm_proto_ah_failed:
1293 	xfrm6_protocol_deregister(&vti_esp6_protocol, IPPROTO_ESP);
1294 xfrm_proto_esp_failed:
1295 	unregister_pernet_device(&vti6_net_ops);
1296 pernet_dev_failed:
1297 	pr_err("vti6 init: failed to register %s\n", msg);
1298 	return err;
1299 }
1300 
1301 /**
1302  * vti6_tunnel_cleanup - free resources and unregister protocol
1303  **/
vti6_tunnel_cleanup(void)1304 static void __exit vti6_tunnel_cleanup(void)
1305 {
1306 	rtnl_link_unregister(&vti6_link_ops);
1307 #if IS_REACHABLE(CONFIG_INET6_XFRM_TUNNEL)
1308 	xfrm6_tunnel_deregister(&vti_ip6ip_handler, AF_INET);
1309 	xfrm6_tunnel_deregister(&vti_ipv6_handler, AF_INET6);
1310 #endif
1311 	xfrm6_protocol_deregister(&vti_ipcomp6_protocol, IPPROTO_COMP);
1312 	xfrm6_protocol_deregister(&vti_ah6_protocol, IPPROTO_AH);
1313 	xfrm6_protocol_deregister(&vti_esp6_protocol, IPPROTO_ESP);
1314 	unregister_pernet_device(&vti6_net_ops);
1315 }
1316 
1317 module_init(vti6_tunnel_init);
1318 module_exit(vti6_tunnel_cleanup);
1319 MODULE_LICENSE("GPL");
1320 MODULE_ALIAS_RTNL_LINK("vti6");
1321 MODULE_ALIAS_NETDEV("ip6_vti0");
1322 MODULE_AUTHOR("Steffen Klassert");
1323 MODULE_DESCRIPTION("IPv6 virtual tunnel interface");
1324