xref: /openbmc/linux/net/ipv4/ip_vti.c (revision f9a82c48)
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_input_ipip(struct sk_buff *skb, int nexthdr, __be32 spi,
78 		     int encap_type)
79 {
80 	struct ip_tunnel *tunnel;
81 	const struct iphdr *iph = ip_hdr(skb);
82 	struct net *net = dev_net(skb->dev);
83 	struct ip_tunnel_net *itn = net_generic(net, vti_net_id);
84 
85 	tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY,
86 				  iph->saddr, iph->daddr, 0);
87 	if (tunnel) {
88 		if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
89 			goto drop;
90 
91 		XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = tunnel;
92 
93 		skb->dev = tunnel->dev;
94 
95 		return xfrm_input(skb, nexthdr, spi, encap_type);
96 	}
97 
98 	return -EINVAL;
99 drop:
100 	kfree_skb(skb);
101 	return 0;
102 }
103 
104 static int vti_rcv(struct sk_buff *skb)
105 {
106 	XFRM_SPI_SKB_CB(skb)->family = AF_INET;
107 	XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct iphdr, daddr);
108 
109 	return vti_input(skb, ip_hdr(skb)->protocol, 0, 0);
110 }
111 
112 static int vti_rcv_ipip(struct sk_buff *skb)
113 {
114 	XFRM_SPI_SKB_CB(skb)->family = AF_INET;
115 	XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct iphdr, daddr);
116 
117 	return vti_input_ipip(skb, ip_hdr(skb)->protocol, ip_hdr(skb)->saddr, 0);
118 }
119 
120 static int vti_rcv_cb(struct sk_buff *skb, int err)
121 {
122 	unsigned short family;
123 	struct net_device *dev;
124 	struct pcpu_sw_netstats *tstats;
125 	struct xfrm_state *x;
126 	struct xfrm_mode *inner_mode;
127 	struct ip_tunnel *tunnel = XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4;
128 	u32 orig_mark = skb->mark;
129 	int ret;
130 
131 	if (!tunnel)
132 		return 1;
133 
134 	dev = tunnel->dev;
135 
136 	if (err) {
137 		dev->stats.rx_errors++;
138 		dev->stats.rx_dropped++;
139 
140 		return 0;
141 	}
142 
143 	x = xfrm_input_state(skb);
144 
145 	inner_mode = x->inner_mode;
146 
147 	if (x->sel.family == AF_UNSPEC) {
148 		inner_mode = xfrm_ip2inner_mode(x, XFRM_MODE_SKB_CB(skb)->protocol);
149 		if (inner_mode == NULL) {
150 			XFRM_INC_STATS(dev_net(skb->dev),
151 				       LINUX_MIB_XFRMINSTATEMODEERROR);
152 			return -EINVAL;
153 		}
154 	}
155 
156 	family = inner_mode->afinfo->family;
157 
158 	skb->mark = be32_to_cpu(tunnel->parms.i_key);
159 	ret = xfrm_policy_check(NULL, XFRM_POLICY_IN, skb, family);
160 	skb->mark = orig_mark;
161 
162 	if (!ret)
163 		return -EPERM;
164 
165 	skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(skb->dev)));
166 	skb->dev = dev;
167 
168 	tstats = this_cpu_ptr(dev->tstats);
169 
170 	u64_stats_update_begin(&tstats->syncp);
171 	tstats->rx_packets++;
172 	tstats->rx_bytes += skb->len;
173 	u64_stats_update_end(&tstats->syncp);
174 
175 	return 0;
176 }
177 
178 static bool vti_state_check(const struct xfrm_state *x, __be32 dst, __be32 src)
179 {
180 	xfrm_address_t *daddr = (xfrm_address_t *)&dst;
181 	xfrm_address_t *saddr = (xfrm_address_t *)&src;
182 
183 	/* if there is no transform then this tunnel is not functional.
184 	 * Or if the xfrm is not mode tunnel.
185 	 */
186 	if (!x || x->props.mode != XFRM_MODE_TUNNEL ||
187 	    x->props.family != AF_INET)
188 		return false;
189 
190 	if (!dst)
191 		return xfrm_addr_equal(saddr, &x->props.saddr, AF_INET);
192 
193 	if (!xfrm_state_addr_check(x, daddr, saddr, AF_INET))
194 		return false;
195 
196 	return true;
197 }
198 
199 static netdev_tx_t vti_xmit(struct sk_buff *skb, struct net_device *dev,
200 			    struct flowi *fl)
201 {
202 	struct ip_tunnel *tunnel = netdev_priv(dev);
203 	struct ip_tunnel_parm *parms = &tunnel->parms;
204 	struct dst_entry *dst = skb_dst(skb);
205 	struct net_device *tdev;	/* Device to other host */
206 	int pkt_len = skb->len;
207 	int err;
208 	int mtu;
209 
210 	if (!dst) {
211 		dev->stats.tx_carrier_errors++;
212 		goto tx_error_icmp;
213 	}
214 
215 	dst_hold(dst);
216 	dst = xfrm_lookup(tunnel->net, dst, fl, NULL, 0);
217 	if (IS_ERR(dst)) {
218 		dev->stats.tx_carrier_errors++;
219 		goto tx_error_icmp;
220 	}
221 
222 	if (!vti_state_check(dst->xfrm, parms->iph.daddr, parms->iph.saddr)) {
223 		dev->stats.tx_carrier_errors++;
224 		dst_release(dst);
225 		goto tx_error_icmp;
226 	}
227 
228 	tdev = dst->dev;
229 
230 	if (tdev == dev) {
231 		dst_release(dst);
232 		dev->stats.collisions++;
233 		goto tx_error;
234 	}
235 
236 	mtu = dst_mtu(dst);
237 	if (skb->len > mtu) {
238 		skb_dst_update_pmtu(skb, mtu);
239 		if (skb->protocol == htons(ETH_P_IP)) {
240 			icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
241 				  htonl(mtu));
242 		} else {
243 			if (mtu < IPV6_MIN_MTU)
244 				mtu = IPV6_MIN_MTU;
245 
246 			icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
247 		}
248 
249 		dst_release(dst);
250 		goto tx_error;
251 	}
252 
253 	skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(dev)));
254 	skb_dst_set(skb, dst);
255 	skb->dev = skb_dst(skb)->dev;
256 
257 	err = dst_output(tunnel->net, skb->sk, skb);
258 	if (net_xmit_eval(err) == 0)
259 		err = pkt_len;
260 	iptunnel_xmit_stats(dev, err);
261 	return NETDEV_TX_OK;
262 
263 tx_error_icmp:
264 	dst_link_failure(skb);
265 tx_error:
266 	dev->stats.tx_errors++;
267 	kfree_skb(skb);
268 	return NETDEV_TX_OK;
269 }
270 
271 /* This function assumes it is being called from dev_queue_xmit()
272  * and that skb is filled properly by that function.
273  */
274 static netdev_tx_t vti_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
275 {
276 	struct ip_tunnel *tunnel = netdev_priv(dev);
277 	struct flowi fl;
278 
279 	if (!pskb_inet_may_pull(skb))
280 		goto tx_err;
281 
282 	memset(&fl, 0, sizeof(fl));
283 
284 	switch (skb->protocol) {
285 	case htons(ETH_P_IP):
286 		xfrm_decode_session(skb, &fl, AF_INET);
287 		memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
288 		break;
289 	case htons(ETH_P_IPV6):
290 		xfrm_decode_session(skb, &fl, AF_INET6);
291 		memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
292 		break;
293 	default:
294 		goto tx_err;
295 	}
296 
297 	/* override mark with tunnel output key */
298 	fl.flowi_mark = be32_to_cpu(tunnel->parms.o_key);
299 
300 	return vti_xmit(skb, dev, &fl);
301 
302 tx_err:
303 	dev->stats.tx_errors++;
304 	kfree_skb(skb);
305 	return NETDEV_TX_OK;
306 }
307 
308 static int vti4_err(struct sk_buff *skb, u32 info)
309 {
310 	__be32 spi;
311 	__u32 mark;
312 	struct xfrm_state *x;
313 	struct ip_tunnel *tunnel;
314 	struct ip_esp_hdr *esph;
315 	struct ip_auth_hdr *ah ;
316 	struct ip_comp_hdr *ipch;
317 	struct net *net = dev_net(skb->dev);
318 	const struct iphdr *iph = (const struct iphdr *)skb->data;
319 	int protocol = iph->protocol;
320 	struct ip_tunnel_net *itn = net_generic(net, vti_net_id);
321 
322 	tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY,
323 				  iph->daddr, iph->saddr, 0);
324 	if (!tunnel)
325 		return -1;
326 
327 	mark = be32_to_cpu(tunnel->parms.o_key);
328 
329 	switch (protocol) {
330 	case IPPROTO_ESP:
331 		esph = (struct ip_esp_hdr *)(skb->data+(iph->ihl<<2));
332 		spi = esph->spi;
333 		break;
334 	case IPPROTO_AH:
335 		ah = (struct ip_auth_hdr *)(skb->data+(iph->ihl<<2));
336 		spi = ah->spi;
337 		break;
338 	case IPPROTO_COMP:
339 		ipch = (struct ip_comp_hdr *)(skb->data+(iph->ihl<<2));
340 		spi = htonl(ntohs(ipch->cpi));
341 		break;
342 	default:
343 		return 0;
344 	}
345 
346 	switch (icmp_hdr(skb)->type) {
347 	case ICMP_DEST_UNREACH:
348 		if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
349 			return 0;
350 	case ICMP_REDIRECT:
351 		break;
352 	default:
353 		return 0;
354 	}
355 
356 	x = xfrm_state_lookup(net, mark, (const xfrm_address_t *)&iph->daddr,
357 			      spi, protocol, AF_INET);
358 	if (!x)
359 		return 0;
360 
361 	if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH)
362 		ipv4_update_pmtu(skb, net, info, 0, protocol);
363 	else
364 		ipv4_redirect(skb, net, 0, protocol);
365 	xfrm_state_put(x);
366 
367 	return 0;
368 }
369 
370 static int
371 vti_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
372 {
373 	int err = 0;
374 	struct ip_tunnel_parm p;
375 
376 	if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
377 		return -EFAULT;
378 
379 	if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) {
380 		if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPIP ||
381 		    p.iph.ihl != 5)
382 			return -EINVAL;
383 	}
384 
385 	if (!(p.i_flags & GRE_KEY))
386 		p.i_key = 0;
387 	if (!(p.o_flags & GRE_KEY))
388 		p.o_key = 0;
389 
390 	p.i_flags = VTI_ISVTI;
391 
392 	err = ip_tunnel_ioctl(dev, &p, cmd);
393 	if (err)
394 		return err;
395 
396 	if (cmd != SIOCDELTUNNEL) {
397 		p.i_flags |= GRE_KEY;
398 		p.o_flags |= GRE_KEY;
399 	}
400 
401 	if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
402 		return -EFAULT;
403 	return 0;
404 }
405 
406 static const struct net_device_ops vti_netdev_ops = {
407 	.ndo_init	= vti_tunnel_init,
408 	.ndo_uninit	= ip_tunnel_uninit,
409 	.ndo_start_xmit	= vti_tunnel_xmit,
410 	.ndo_do_ioctl	= vti_tunnel_ioctl,
411 	.ndo_change_mtu	= ip_tunnel_change_mtu,
412 	.ndo_get_stats64 = ip_tunnel_get_stats64,
413 	.ndo_get_iflink = ip_tunnel_get_iflink,
414 };
415 
416 static void vti_tunnel_setup(struct net_device *dev)
417 {
418 	dev->netdev_ops		= &vti_netdev_ops;
419 	dev->type		= ARPHRD_TUNNEL;
420 	ip_tunnel_setup(dev, vti_net_id);
421 }
422 
423 static int vti_tunnel_init(struct net_device *dev)
424 {
425 	struct ip_tunnel *tunnel = netdev_priv(dev);
426 	struct iphdr *iph = &tunnel->parms.iph;
427 
428 	memcpy(dev->dev_addr, &iph->saddr, 4);
429 	memcpy(dev->broadcast, &iph->daddr, 4);
430 
431 	dev->flags		= IFF_NOARP;
432 	dev->addr_len		= 4;
433 	dev->features		|= NETIF_F_LLTX;
434 	netif_keep_dst(dev);
435 
436 	return ip_tunnel_init(dev);
437 }
438 
439 static void __net_init vti_fb_tunnel_init(struct net_device *dev)
440 {
441 	struct ip_tunnel *tunnel = netdev_priv(dev);
442 	struct iphdr *iph = &tunnel->parms.iph;
443 
444 	iph->version		= 4;
445 	iph->protocol		= IPPROTO_IPIP;
446 	iph->ihl		= 5;
447 }
448 
449 static struct xfrm4_protocol vti_esp4_protocol __read_mostly = {
450 	.handler	=	vti_rcv,
451 	.input_handler	=	vti_input,
452 	.cb_handler	=	vti_rcv_cb,
453 	.err_handler	=	vti4_err,
454 	.priority	=	100,
455 };
456 
457 static struct xfrm4_protocol vti_ah4_protocol __read_mostly = {
458 	.handler	=	vti_rcv,
459 	.input_handler	=	vti_input,
460 	.cb_handler	=	vti_rcv_cb,
461 	.err_handler	=	vti4_err,
462 	.priority	=	100,
463 };
464 
465 static struct xfrm4_protocol vti_ipcomp4_protocol __read_mostly = {
466 	.handler	=	vti_rcv,
467 	.input_handler	=	vti_input,
468 	.cb_handler	=	vti_rcv_cb,
469 	.err_handler	=	vti4_err,
470 	.priority	=	100,
471 };
472 
473 static struct xfrm_tunnel ipip_handler __read_mostly = {
474 	.handler	=	vti_rcv_ipip,
475 	.err_handler	=	vti4_err,
476 	.priority	=	0,
477 };
478 
479 static int __net_init vti_init_net(struct net *net)
480 {
481 	int err;
482 	struct ip_tunnel_net *itn;
483 
484 	err = ip_tunnel_init_net(net, vti_net_id, &vti_link_ops, "ip_vti0");
485 	if (err)
486 		return err;
487 	itn = net_generic(net, vti_net_id);
488 	if (itn->fb_tunnel_dev)
489 		vti_fb_tunnel_init(itn->fb_tunnel_dev);
490 	return 0;
491 }
492 
493 static void __net_exit vti_exit_batch_net(struct list_head *list_net)
494 {
495 	ip_tunnel_delete_nets(list_net, vti_net_id, &vti_link_ops);
496 }
497 
498 static struct pernet_operations vti_net_ops = {
499 	.init = vti_init_net,
500 	.exit_batch = vti_exit_batch_net,
501 	.id   = &vti_net_id,
502 	.size = sizeof(struct ip_tunnel_net),
503 };
504 
505 static int vti_tunnel_validate(struct nlattr *tb[], struct nlattr *data[],
506 			       struct netlink_ext_ack *extack)
507 {
508 	return 0;
509 }
510 
511 static void vti_netlink_parms(struct nlattr *data[],
512 			      struct ip_tunnel_parm *parms,
513 			      __u32 *fwmark)
514 {
515 	memset(parms, 0, sizeof(*parms));
516 
517 	parms->iph.protocol = IPPROTO_IPIP;
518 
519 	if (!data)
520 		return;
521 
522 	parms->i_flags = VTI_ISVTI;
523 
524 	if (data[IFLA_VTI_LINK])
525 		parms->link = nla_get_u32(data[IFLA_VTI_LINK]);
526 
527 	if (data[IFLA_VTI_IKEY])
528 		parms->i_key = nla_get_be32(data[IFLA_VTI_IKEY]);
529 
530 	if (data[IFLA_VTI_OKEY])
531 		parms->o_key = nla_get_be32(data[IFLA_VTI_OKEY]);
532 
533 	if (data[IFLA_VTI_LOCAL])
534 		parms->iph.saddr = nla_get_in_addr(data[IFLA_VTI_LOCAL]);
535 
536 	if (data[IFLA_VTI_REMOTE])
537 		parms->iph.daddr = nla_get_in_addr(data[IFLA_VTI_REMOTE]);
538 
539 	if (data[IFLA_VTI_FWMARK])
540 		*fwmark = nla_get_u32(data[IFLA_VTI_FWMARK]);
541 }
542 
543 static int vti_newlink(struct net *src_net, struct net_device *dev,
544 		       struct nlattr *tb[], struct nlattr *data[],
545 		       struct netlink_ext_ack *extack)
546 {
547 	struct ip_tunnel_parm parms;
548 	__u32 fwmark = 0;
549 
550 	vti_netlink_parms(data, &parms, &fwmark);
551 	return ip_tunnel_newlink(dev, tb, &parms, fwmark);
552 }
553 
554 static int vti_changelink(struct net_device *dev, struct nlattr *tb[],
555 			  struct nlattr *data[],
556 			  struct netlink_ext_ack *extack)
557 {
558 	struct ip_tunnel *t = netdev_priv(dev);
559 	__u32 fwmark = t->fwmark;
560 	struct ip_tunnel_parm p;
561 
562 	vti_netlink_parms(data, &p, &fwmark);
563 	return ip_tunnel_changelink(dev, tb, &p, fwmark);
564 }
565 
566 static size_t vti_get_size(const struct net_device *dev)
567 {
568 	return
569 		/* IFLA_VTI_LINK */
570 		nla_total_size(4) +
571 		/* IFLA_VTI_IKEY */
572 		nla_total_size(4) +
573 		/* IFLA_VTI_OKEY */
574 		nla_total_size(4) +
575 		/* IFLA_VTI_LOCAL */
576 		nla_total_size(4) +
577 		/* IFLA_VTI_REMOTE */
578 		nla_total_size(4) +
579 		/* IFLA_VTI_FWMARK */
580 		nla_total_size(4) +
581 		0;
582 }
583 
584 static int vti_fill_info(struct sk_buff *skb, const struct net_device *dev)
585 {
586 	struct ip_tunnel *t = netdev_priv(dev);
587 	struct ip_tunnel_parm *p = &t->parms;
588 
589 	if (nla_put_u32(skb, IFLA_VTI_LINK, p->link) ||
590 	    nla_put_be32(skb, IFLA_VTI_IKEY, p->i_key) ||
591 	    nla_put_be32(skb, IFLA_VTI_OKEY, p->o_key) ||
592 	    nla_put_in_addr(skb, IFLA_VTI_LOCAL, p->iph.saddr) ||
593 	    nla_put_in_addr(skb, IFLA_VTI_REMOTE, p->iph.daddr) ||
594 	    nla_put_u32(skb, IFLA_VTI_FWMARK, t->fwmark))
595 		return -EMSGSIZE;
596 
597 	return 0;
598 }
599 
600 static const struct nla_policy vti_policy[IFLA_VTI_MAX + 1] = {
601 	[IFLA_VTI_LINK]		= { .type = NLA_U32 },
602 	[IFLA_VTI_IKEY]		= { .type = NLA_U32 },
603 	[IFLA_VTI_OKEY]		= { .type = NLA_U32 },
604 	[IFLA_VTI_LOCAL]	= { .len = FIELD_SIZEOF(struct iphdr, saddr) },
605 	[IFLA_VTI_REMOTE]	= { .len = FIELD_SIZEOF(struct iphdr, daddr) },
606 	[IFLA_VTI_FWMARK]	= { .type = NLA_U32 },
607 };
608 
609 static struct rtnl_link_ops vti_link_ops __read_mostly = {
610 	.kind		= "vti",
611 	.maxtype	= IFLA_VTI_MAX,
612 	.policy		= vti_policy,
613 	.priv_size	= sizeof(struct ip_tunnel),
614 	.setup		= vti_tunnel_setup,
615 	.validate	= vti_tunnel_validate,
616 	.newlink	= vti_newlink,
617 	.changelink	= vti_changelink,
618 	.dellink        = ip_tunnel_dellink,
619 	.get_size	= vti_get_size,
620 	.fill_info	= vti_fill_info,
621 	.get_link_net	= ip_tunnel_get_link_net,
622 };
623 
624 static int __init vti_init(void)
625 {
626 	const char *msg;
627 	int err;
628 
629 	pr_info("IPv4 over IPsec tunneling driver\n");
630 
631 	msg = "tunnel device";
632 	err = register_pernet_device(&vti_net_ops);
633 	if (err < 0)
634 		goto pernet_dev_failed;
635 
636 	msg = "tunnel protocols";
637 	err = xfrm4_protocol_register(&vti_esp4_protocol, IPPROTO_ESP);
638 	if (err < 0)
639 		goto xfrm_proto_esp_failed;
640 	err = xfrm4_protocol_register(&vti_ah4_protocol, IPPROTO_AH);
641 	if (err < 0)
642 		goto xfrm_proto_ah_failed;
643 	err = xfrm4_protocol_register(&vti_ipcomp4_protocol, IPPROTO_COMP);
644 	if (err < 0)
645 		goto xfrm_proto_comp_failed;
646 
647 	msg = "ipip tunnel";
648 	err = xfrm4_tunnel_register(&ipip_handler, AF_INET);
649 	if (err < 0) {
650 		pr_info("%s: cant't register tunnel\n",__func__);
651 		goto xfrm_tunnel_failed;
652 	}
653 
654 	msg = "netlink interface";
655 	err = rtnl_link_register(&vti_link_ops);
656 	if (err < 0)
657 		goto rtnl_link_failed;
658 
659 	return err;
660 
661 rtnl_link_failed:
662 	xfrm4_protocol_deregister(&vti_ipcomp4_protocol, IPPROTO_COMP);
663 xfrm_tunnel_failed:
664 	xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
665 xfrm_proto_comp_failed:
666 	xfrm4_protocol_deregister(&vti_ah4_protocol, IPPROTO_AH);
667 xfrm_proto_ah_failed:
668 	xfrm4_protocol_deregister(&vti_esp4_protocol, IPPROTO_ESP);
669 xfrm_proto_esp_failed:
670 	unregister_pernet_device(&vti_net_ops);
671 pernet_dev_failed:
672 	pr_err("vti init: failed to register %s\n", msg);
673 	return err;
674 }
675 
676 static void __exit vti_fini(void)
677 {
678 	rtnl_link_unregister(&vti_link_ops);
679 	xfrm4_protocol_deregister(&vti_ipcomp4_protocol, IPPROTO_COMP);
680 	xfrm4_protocol_deregister(&vti_ah4_protocol, IPPROTO_AH);
681 	xfrm4_protocol_deregister(&vti_esp4_protocol, IPPROTO_ESP);
682 	unregister_pernet_device(&vti_net_ops);
683 }
684 
685 module_init(vti_init);
686 module_exit(vti_fini);
687 MODULE_LICENSE("GPL");
688 MODULE_ALIAS_RTNL_LINK("vti");
689 MODULE_ALIAS_NETDEV("ip_vti0");
690