xref: /openbmc/linux/net/ipv4/ip_vti.c (revision 612a462a)
1 /*
2  *	Linux NET3: IP/IP protocol decoder modified to support
3  *		    virtual tunnel interface
4  *
5  *	Authors:
6  *		Saurabh Mohan (saurabh.mohan@vyatta.com) 05/07/2012
7  *
8  *	This program is free software; you can redistribute it and/or
9  *	modify it under the terms of the GNU General Public License
10  *	as published by the Free Software Foundation; either version
11  *	2 of the License, or (at your option) any later version.
12  *
13  */
14 
15 /*
16    This version of net/ipv4/ip_vti.c is cloned of net/ipv4/ipip.c
17 
18    For comments look at net/ipv4/ip_gre.c --ANK
19  */
20 
21 
22 #include <linux/capability.h>
23 #include <linux/module.h>
24 #include <linux/types.h>
25 #include <linux/kernel.h>
26 #include <linux/uaccess.h>
27 #include <linux/skbuff.h>
28 #include <linux/netdevice.h>
29 #include <linux/in.h>
30 #include <linux/tcp.h>
31 #include <linux/udp.h>
32 #include <linux/if_arp.h>
33 #include <linux/init.h>
34 #include <linux/netfilter_ipv4.h>
35 #include <linux/if_ether.h>
36 #include <linux/icmpv6.h>
37 
38 #include <net/sock.h>
39 #include <net/ip.h>
40 #include <net/icmp.h>
41 #include <net/ip_tunnels.h>
42 #include <net/inet_ecn.h>
43 #include <net/xfrm.h>
44 #include <net/net_namespace.h>
45 #include <net/netns/generic.h>
46 
47 static struct rtnl_link_ops vti_link_ops __read_mostly;
48 
49 static unsigned int vti_net_id __read_mostly;
50 static int vti_tunnel_init(struct net_device *dev);
51 
52 static int vti_input(struct sk_buff *skb, int nexthdr, __be32 spi,
53 		     int encap_type)
54 {
55 	struct ip_tunnel *tunnel;
56 	const struct iphdr *iph = ip_hdr(skb);
57 	struct net *net = dev_net(skb->dev);
58 	struct ip_tunnel_net *itn = net_generic(net, vti_net_id);
59 
60 	tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY,
61 				  iph->saddr, iph->daddr, 0);
62 	if (tunnel) {
63 		if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
64 			goto drop;
65 
66 		XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = tunnel;
67 
68 		return xfrm_input(skb, nexthdr, spi, encap_type);
69 	}
70 
71 	return -EINVAL;
72 drop:
73 	kfree_skb(skb);
74 	return 0;
75 }
76 
77 static int vti_rcv(struct sk_buff *skb)
78 {
79 	XFRM_SPI_SKB_CB(skb)->family = AF_INET;
80 	XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct iphdr, daddr);
81 
82 	return vti_input(skb, ip_hdr(skb)->protocol, 0, 0);
83 }
84 
85 static int vti_rcv_cb(struct sk_buff *skb, int err)
86 {
87 	unsigned short family;
88 	struct net_device *dev;
89 	struct pcpu_sw_netstats *tstats;
90 	struct xfrm_state *x;
91 	struct xfrm_mode *inner_mode;
92 	struct ip_tunnel *tunnel = XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4;
93 	u32 orig_mark = skb->mark;
94 	int ret;
95 
96 	if (!tunnel)
97 		return 1;
98 
99 	dev = tunnel->dev;
100 
101 	if (err) {
102 		dev->stats.rx_errors++;
103 		dev->stats.rx_dropped++;
104 
105 		return 0;
106 	}
107 
108 	x = xfrm_input_state(skb);
109 
110 	inner_mode = x->inner_mode;
111 
112 	if (x->sel.family == AF_UNSPEC) {
113 		inner_mode = xfrm_ip2inner_mode(x, XFRM_MODE_SKB_CB(skb)->protocol);
114 		if (inner_mode == NULL) {
115 			XFRM_INC_STATS(dev_net(skb->dev),
116 				       LINUX_MIB_XFRMINSTATEMODEERROR);
117 			return -EINVAL;
118 		}
119 	}
120 
121 	family = inner_mode->afinfo->family;
122 
123 	skb->mark = be32_to_cpu(tunnel->parms.i_key);
124 	ret = xfrm_policy_check(NULL, XFRM_POLICY_IN, skb, family);
125 	skb->mark = orig_mark;
126 
127 	if (!ret)
128 		return -EPERM;
129 
130 	skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(skb->dev)));
131 	skb->dev = dev;
132 
133 	tstats = this_cpu_ptr(dev->tstats);
134 
135 	u64_stats_update_begin(&tstats->syncp);
136 	tstats->rx_packets++;
137 	tstats->rx_bytes += skb->len;
138 	u64_stats_update_end(&tstats->syncp);
139 
140 	return 0;
141 }
142 
143 static bool vti_state_check(const struct xfrm_state *x, __be32 dst, __be32 src)
144 {
145 	xfrm_address_t *daddr = (xfrm_address_t *)&dst;
146 	xfrm_address_t *saddr = (xfrm_address_t *)&src;
147 
148 	/* if there is no transform then this tunnel is not functional.
149 	 * Or if the xfrm is not mode tunnel.
150 	 */
151 	if (!x || x->props.mode != XFRM_MODE_TUNNEL ||
152 	    x->props.family != AF_INET)
153 		return false;
154 
155 	if (!dst)
156 		return xfrm_addr_equal(saddr, &x->props.saddr, AF_INET);
157 
158 	if (!xfrm_state_addr_check(x, daddr, saddr, AF_INET))
159 		return false;
160 
161 	return true;
162 }
163 
164 static netdev_tx_t vti_xmit(struct sk_buff *skb, struct net_device *dev,
165 			    struct flowi *fl)
166 {
167 	struct ip_tunnel *tunnel = netdev_priv(dev);
168 	struct ip_tunnel_parm *parms = &tunnel->parms;
169 	struct dst_entry *dst = skb_dst(skb);
170 	struct net_device *tdev;	/* Device to other host */
171 	int pkt_len = skb->len;
172 	int err;
173 	int mtu;
174 
175 	if (!dst) {
176 		dev->stats.tx_carrier_errors++;
177 		goto tx_error_icmp;
178 	}
179 
180 	dst_hold(dst);
181 	dst = xfrm_lookup(tunnel->net, dst, fl, NULL, 0);
182 	if (IS_ERR(dst)) {
183 		dev->stats.tx_carrier_errors++;
184 		goto tx_error_icmp;
185 	}
186 
187 	if (!vti_state_check(dst->xfrm, parms->iph.daddr, parms->iph.saddr)) {
188 		dev->stats.tx_carrier_errors++;
189 		dst_release(dst);
190 		goto tx_error_icmp;
191 	}
192 
193 	tdev = dst->dev;
194 
195 	if (tdev == dev) {
196 		dst_release(dst);
197 		dev->stats.collisions++;
198 		goto tx_error;
199 	}
200 
201 	if (tunnel->err_count > 0) {
202 		if (time_before(jiffies,
203 				tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
204 			tunnel->err_count--;
205 			dst_link_failure(skb);
206 		} else
207 			tunnel->err_count = 0;
208 	}
209 
210 	mtu = dst_mtu(dst);
211 	if (skb->len > mtu) {
212 		skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
213 		if (skb->protocol == htons(ETH_P_IP)) {
214 			icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
215 				  htonl(mtu));
216 		} else {
217 			if (mtu < IPV6_MIN_MTU)
218 				mtu = IPV6_MIN_MTU;
219 
220 			icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
221 		}
222 
223 		dst_release(dst);
224 		goto tx_error;
225 	}
226 
227 	skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(dev)));
228 	skb_dst_set(skb, dst);
229 	skb->dev = skb_dst(skb)->dev;
230 
231 	err = dst_output(tunnel->net, skb->sk, skb);
232 	if (net_xmit_eval(err) == 0)
233 		err = pkt_len;
234 	iptunnel_xmit_stats(dev, err);
235 	return NETDEV_TX_OK;
236 
237 tx_error_icmp:
238 	dst_link_failure(skb);
239 tx_error:
240 	dev->stats.tx_errors++;
241 	kfree_skb(skb);
242 	return NETDEV_TX_OK;
243 }
244 
245 /* This function assumes it is being called from dev_queue_xmit()
246  * and that skb is filled properly by that function.
247  */
248 static netdev_tx_t vti_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
249 {
250 	struct ip_tunnel *tunnel = netdev_priv(dev);
251 	struct flowi fl;
252 
253 	memset(&fl, 0, sizeof(fl));
254 
255 	switch (skb->protocol) {
256 	case htons(ETH_P_IP):
257 		xfrm_decode_session(skb, &fl, AF_INET);
258 		memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
259 		break;
260 	case htons(ETH_P_IPV6):
261 		xfrm_decode_session(skb, &fl, AF_INET6);
262 		memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
263 		break;
264 	default:
265 		dev->stats.tx_errors++;
266 		dev_kfree_skb(skb);
267 		return NETDEV_TX_OK;
268 	}
269 
270 	/* override mark with tunnel output key */
271 	fl.flowi_mark = be32_to_cpu(tunnel->parms.o_key);
272 
273 	return vti_xmit(skb, dev, &fl);
274 }
275 
276 static int vti4_err(struct sk_buff *skb, u32 info)
277 {
278 	__be32 spi;
279 	__u32 mark;
280 	struct xfrm_state *x;
281 	struct ip_tunnel *tunnel;
282 	struct ip_esp_hdr *esph;
283 	struct ip_auth_hdr *ah ;
284 	struct ip_comp_hdr *ipch;
285 	struct net *net = dev_net(skb->dev);
286 	const struct iphdr *iph = (const struct iphdr *)skb->data;
287 	int protocol = iph->protocol;
288 	struct ip_tunnel_net *itn = net_generic(net, vti_net_id);
289 
290 	tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY,
291 				  iph->daddr, iph->saddr, 0);
292 	if (!tunnel)
293 		return -1;
294 
295 	mark = be32_to_cpu(tunnel->parms.o_key);
296 
297 	switch (protocol) {
298 	case IPPROTO_ESP:
299 		esph = (struct ip_esp_hdr *)(skb->data+(iph->ihl<<2));
300 		spi = esph->spi;
301 		break;
302 	case IPPROTO_AH:
303 		ah = (struct ip_auth_hdr *)(skb->data+(iph->ihl<<2));
304 		spi = ah->spi;
305 		break;
306 	case IPPROTO_COMP:
307 		ipch = (struct ip_comp_hdr *)(skb->data+(iph->ihl<<2));
308 		spi = htonl(ntohs(ipch->cpi));
309 		break;
310 	default:
311 		return 0;
312 	}
313 
314 	switch (icmp_hdr(skb)->type) {
315 	case ICMP_DEST_UNREACH:
316 		if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
317 			return 0;
318 	case ICMP_REDIRECT:
319 		break;
320 	default:
321 		return 0;
322 	}
323 
324 	x = xfrm_state_lookup(net, mark, (const xfrm_address_t *)&iph->daddr,
325 			      spi, protocol, AF_INET);
326 	if (!x)
327 		return 0;
328 
329 	if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH)
330 		ipv4_update_pmtu(skb, net, info, 0, 0, protocol, 0);
331 	else
332 		ipv4_redirect(skb, net, 0, 0, protocol, 0);
333 	xfrm_state_put(x);
334 
335 	return 0;
336 }
337 
338 static int
339 vti_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
340 {
341 	int err = 0;
342 	struct ip_tunnel_parm p;
343 
344 	if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
345 		return -EFAULT;
346 
347 	if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) {
348 		if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPIP ||
349 		    p.iph.ihl != 5)
350 			return -EINVAL;
351 	}
352 
353 	if (!(p.i_flags & GRE_KEY))
354 		p.i_key = 0;
355 	if (!(p.o_flags & GRE_KEY))
356 		p.o_key = 0;
357 
358 	p.i_flags = VTI_ISVTI;
359 
360 	err = ip_tunnel_ioctl(dev, &p, cmd);
361 	if (err)
362 		return err;
363 
364 	if (cmd != SIOCDELTUNNEL) {
365 		p.i_flags |= GRE_KEY;
366 		p.o_flags |= GRE_KEY;
367 	}
368 
369 	if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
370 		return -EFAULT;
371 	return 0;
372 }
373 
374 static const struct net_device_ops vti_netdev_ops = {
375 	.ndo_init	= vti_tunnel_init,
376 	.ndo_uninit	= ip_tunnel_uninit,
377 	.ndo_start_xmit	= vti_tunnel_xmit,
378 	.ndo_do_ioctl	= vti_tunnel_ioctl,
379 	.ndo_change_mtu	= ip_tunnel_change_mtu,
380 	.ndo_get_stats64 = ip_tunnel_get_stats64,
381 	.ndo_get_iflink = ip_tunnel_get_iflink,
382 };
383 
384 static void vti_tunnel_setup(struct net_device *dev)
385 {
386 	dev->netdev_ops		= &vti_netdev_ops;
387 	dev->type		= ARPHRD_TUNNEL;
388 	ip_tunnel_setup(dev, vti_net_id);
389 }
390 
391 static int vti_tunnel_init(struct net_device *dev)
392 {
393 	struct ip_tunnel *tunnel = netdev_priv(dev);
394 	struct iphdr *iph = &tunnel->parms.iph;
395 
396 	memcpy(dev->dev_addr, &iph->saddr, 4);
397 	memcpy(dev->broadcast, &iph->daddr, 4);
398 
399 	dev->hard_header_len	= LL_MAX_HEADER + sizeof(struct iphdr);
400 	dev->mtu		= ETH_DATA_LEN;
401 	dev->flags		= IFF_NOARP;
402 	dev->addr_len		= 4;
403 	dev->features		|= NETIF_F_LLTX;
404 	netif_keep_dst(dev);
405 
406 	return ip_tunnel_init(dev);
407 }
408 
409 static void __net_init vti_fb_tunnel_init(struct net_device *dev)
410 {
411 	struct ip_tunnel *tunnel = netdev_priv(dev);
412 	struct iphdr *iph = &tunnel->parms.iph;
413 
414 	iph->version		= 4;
415 	iph->protocol		= IPPROTO_IPIP;
416 	iph->ihl		= 5;
417 }
418 
419 static struct xfrm4_protocol vti_esp4_protocol __read_mostly = {
420 	.handler	=	vti_rcv,
421 	.input_handler	=	vti_input,
422 	.cb_handler	=	vti_rcv_cb,
423 	.err_handler	=	vti4_err,
424 	.priority	=	100,
425 };
426 
427 static struct xfrm4_protocol vti_ah4_protocol __read_mostly = {
428 	.handler	=	vti_rcv,
429 	.input_handler	=	vti_input,
430 	.cb_handler	=	vti_rcv_cb,
431 	.err_handler	=	vti4_err,
432 	.priority	=	100,
433 };
434 
435 static struct xfrm4_protocol vti_ipcomp4_protocol __read_mostly = {
436 	.handler	=	vti_rcv,
437 	.input_handler	=	vti_input,
438 	.cb_handler	=	vti_rcv_cb,
439 	.err_handler	=	vti4_err,
440 	.priority	=	100,
441 };
442 
443 static int __net_init vti_init_net(struct net *net)
444 {
445 	int err;
446 	struct ip_tunnel_net *itn;
447 
448 	err = ip_tunnel_init_net(net, vti_net_id, &vti_link_ops, "ip_vti0");
449 	if (err)
450 		return err;
451 	itn = net_generic(net, vti_net_id);
452 	vti_fb_tunnel_init(itn->fb_tunnel_dev);
453 	return 0;
454 }
455 
456 static void __net_exit vti_exit_net(struct net *net)
457 {
458 	struct ip_tunnel_net *itn = net_generic(net, vti_net_id);
459 	ip_tunnel_delete_net(itn, &vti_link_ops);
460 }
461 
462 static struct pernet_operations vti_net_ops = {
463 	.init = vti_init_net,
464 	.exit = vti_exit_net,
465 	.id   = &vti_net_id,
466 	.size = sizeof(struct ip_tunnel_net),
467 };
468 
469 static int vti_tunnel_validate(struct nlattr *tb[], struct nlattr *data[],
470 			       struct netlink_ext_ack *extack)
471 {
472 	return 0;
473 }
474 
475 static void vti_netlink_parms(struct nlattr *data[],
476 			      struct ip_tunnel_parm *parms,
477 			      __u32 *fwmark)
478 {
479 	memset(parms, 0, sizeof(*parms));
480 
481 	parms->iph.protocol = IPPROTO_IPIP;
482 
483 	if (!data)
484 		return;
485 
486 	parms->i_flags = VTI_ISVTI;
487 
488 	if (data[IFLA_VTI_LINK])
489 		parms->link = nla_get_u32(data[IFLA_VTI_LINK]);
490 
491 	if (data[IFLA_VTI_IKEY])
492 		parms->i_key = nla_get_be32(data[IFLA_VTI_IKEY]);
493 
494 	if (data[IFLA_VTI_OKEY])
495 		parms->o_key = nla_get_be32(data[IFLA_VTI_OKEY]);
496 
497 	if (data[IFLA_VTI_LOCAL])
498 		parms->iph.saddr = nla_get_in_addr(data[IFLA_VTI_LOCAL]);
499 
500 	if (data[IFLA_VTI_REMOTE])
501 		parms->iph.daddr = nla_get_in_addr(data[IFLA_VTI_REMOTE]);
502 
503 	if (data[IFLA_VTI_FWMARK])
504 		*fwmark = nla_get_u32(data[IFLA_VTI_FWMARK]);
505 }
506 
507 static int vti_newlink(struct net *src_net, struct net_device *dev,
508 		       struct nlattr *tb[], struct nlattr *data[],
509 		       struct netlink_ext_ack *extack)
510 {
511 	struct ip_tunnel_parm parms;
512 	__u32 fwmark = 0;
513 
514 	vti_netlink_parms(data, &parms, &fwmark);
515 	return ip_tunnel_newlink(dev, tb, &parms, fwmark);
516 }
517 
518 static int vti_changelink(struct net_device *dev, struct nlattr *tb[],
519 			  struct nlattr *data[],
520 			  struct netlink_ext_ack *extack)
521 {
522 	struct ip_tunnel *t = netdev_priv(dev);
523 	__u32 fwmark = t->fwmark;
524 	struct ip_tunnel_parm p;
525 
526 	vti_netlink_parms(data, &p, &fwmark);
527 	return ip_tunnel_changelink(dev, tb, &p, fwmark);
528 }
529 
530 static size_t vti_get_size(const struct net_device *dev)
531 {
532 	return
533 		/* IFLA_VTI_LINK */
534 		nla_total_size(4) +
535 		/* IFLA_VTI_IKEY */
536 		nla_total_size(4) +
537 		/* IFLA_VTI_OKEY */
538 		nla_total_size(4) +
539 		/* IFLA_VTI_LOCAL */
540 		nla_total_size(4) +
541 		/* IFLA_VTI_REMOTE */
542 		nla_total_size(4) +
543 		/* IFLA_VTI_FWMARK */
544 		nla_total_size(4) +
545 		0;
546 }
547 
548 static int vti_fill_info(struct sk_buff *skb, const struct net_device *dev)
549 {
550 	struct ip_tunnel *t = netdev_priv(dev);
551 	struct ip_tunnel_parm *p = &t->parms;
552 
553 	if (nla_put_u32(skb, IFLA_VTI_LINK, p->link) ||
554 	    nla_put_be32(skb, IFLA_VTI_IKEY, p->i_key) ||
555 	    nla_put_be32(skb, IFLA_VTI_OKEY, p->o_key) ||
556 	    nla_put_in_addr(skb, IFLA_VTI_LOCAL, p->iph.saddr) ||
557 	    nla_put_in_addr(skb, IFLA_VTI_REMOTE, p->iph.daddr) ||
558 	    nla_put_u32(skb, IFLA_VTI_FWMARK, t->fwmark))
559 		return -EMSGSIZE;
560 
561 	return 0;
562 }
563 
564 static const struct nla_policy vti_policy[IFLA_VTI_MAX + 1] = {
565 	[IFLA_VTI_LINK]		= { .type = NLA_U32 },
566 	[IFLA_VTI_IKEY]		= { .type = NLA_U32 },
567 	[IFLA_VTI_OKEY]		= { .type = NLA_U32 },
568 	[IFLA_VTI_LOCAL]	= { .len = FIELD_SIZEOF(struct iphdr, saddr) },
569 	[IFLA_VTI_REMOTE]	= { .len = FIELD_SIZEOF(struct iphdr, daddr) },
570 	[IFLA_VTI_FWMARK]	= { .type = NLA_U32 },
571 };
572 
573 static struct rtnl_link_ops vti_link_ops __read_mostly = {
574 	.kind		= "vti",
575 	.maxtype	= IFLA_VTI_MAX,
576 	.policy		= vti_policy,
577 	.priv_size	= sizeof(struct ip_tunnel),
578 	.setup		= vti_tunnel_setup,
579 	.validate	= vti_tunnel_validate,
580 	.newlink	= vti_newlink,
581 	.changelink	= vti_changelink,
582 	.dellink        = ip_tunnel_dellink,
583 	.get_size	= vti_get_size,
584 	.fill_info	= vti_fill_info,
585 	.get_link_net	= ip_tunnel_get_link_net,
586 };
587 
588 static int __init vti_init(void)
589 {
590 	const char *msg;
591 	int err;
592 
593 	pr_info("IPv4 over IPsec tunneling driver\n");
594 
595 	msg = "tunnel device";
596 	err = register_pernet_device(&vti_net_ops);
597 	if (err < 0)
598 		goto pernet_dev_failed;
599 
600 	msg = "tunnel protocols";
601 	err = xfrm4_protocol_register(&vti_esp4_protocol, IPPROTO_ESP);
602 	if (err < 0)
603 		goto xfrm_proto_esp_failed;
604 	err = xfrm4_protocol_register(&vti_ah4_protocol, IPPROTO_AH);
605 	if (err < 0)
606 		goto xfrm_proto_ah_failed;
607 	err = xfrm4_protocol_register(&vti_ipcomp4_protocol, IPPROTO_COMP);
608 	if (err < 0)
609 		goto xfrm_proto_comp_failed;
610 
611 	msg = "netlink interface";
612 	err = rtnl_link_register(&vti_link_ops);
613 	if (err < 0)
614 		goto rtnl_link_failed;
615 
616 	return err;
617 
618 rtnl_link_failed:
619 	xfrm4_protocol_deregister(&vti_ipcomp4_protocol, IPPROTO_COMP);
620 xfrm_proto_comp_failed:
621 	xfrm4_protocol_deregister(&vti_ah4_protocol, IPPROTO_AH);
622 xfrm_proto_ah_failed:
623 	xfrm4_protocol_deregister(&vti_esp4_protocol, IPPROTO_ESP);
624 xfrm_proto_esp_failed:
625 	unregister_pernet_device(&vti_net_ops);
626 pernet_dev_failed:
627 	pr_err("vti init: failed to register %s\n", msg);
628 	return err;
629 }
630 
631 static void __exit vti_fini(void)
632 {
633 	rtnl_link_unregister(&vti_link_ops);
634 	xfrm4_protocol_deregister(&vti_ipcomp4_protocol, IPPROTO_COMP);
635 	xfrm4_protocol_deregister(&vti_ah4_protocol, IPPROTO_AH);
636 	xfrm4_protocol_deregister(&vti_esp4_protocol, IPPROTO_ESP);
637 	unregister_pernet_device(&vti_net_ops);
638 }
639 
640 module_init(vti_init);
641 module_exit(vti_fini);
642 MODULE_LICENSE("GPL");
643 MODULE_ALIAS_RTNL_LINK("vti");
644 MODULE_ALIAS_NETDEV("ip_vti0");
645