xref: /openbmc/linux/net/ipv4/ip_vti.c (revision adb57164)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *	Linux NET3: IP/IP protocol decoder modified to support
4  *		    virtual tunnel interface
5  *
6  *	Authors:
7  *		Saurabh Mohan (saurabh.mohan@vyatta.com) 05/07/2012
8  */
9 
10 /*
11    This version of net/ipv4/ip_vti.c is cloned of net/ipv4/ipip.c
12 
13    For comments look at net/ipv4/ip_gre.c --ANK
14  */
15 
16 
17 #include <linux/capability.h>
18 #include <linux/module.h>
19 #include <linux/types.h>
20 #include <linux/kernel.h>
21 #include <linux/uaccess.h>
22 #include <linux/skbuff.h>
23 #include <linux/netdevice.h>
24 #include <linux/in.h>
25 #include <linux/tcp.h>
26 #include <linux/udp.h>
27 #include <linux/if_arp.h>
28 #include <linux/init.h>
29 #include <linux/netfilter_ipv4.h>
30 #include <linux/if_ether.h>
31 #include <linux/icmpv6.h>
32 
33 #include <net/sock.h>
34 #include <net/ip.h>
35 #include <net/icmp.h>
36 #include <net/ip_tunnels.h>
37 #include <net/inet_ecn.h>
38 #include <net/xfrm.h>
39 #include <net/net_namespace.h>
40 #include <net/netns/generic.h>
41 
42 static struct rtnl_link_ops vti_link_ops __read_mostly;
43 
44 static unsigned int vti_net_id __read_mostly;
45 static int vti_tunnel_init(struct net_device *dev);
46 
47 static int vti_input(struct sk_buff *skb, int nexthdr, __be32 spi,
48 		     int encap_type, bool update_skb_dev)
49 {
50 	struct ip_tunnel *tunnel;
51 	const struct iphdr *iph = ip_hdr(skb);
52 	struct net *net = dev_net(skb->dev);
53 	struct ip_tunnel_net *itn = net_generic(net, vti_net_id);
54 
55 	tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY,
56 				  iph->saddr, iph->daddr, 0);
57 	if (tunnel) {
58 		if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
59 			goto drop;
60 
61 		XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = tunnel;
62 
63 		if (update_skb_dev)
64 			skb->dev = tunnel->dev;
65 
66 		return xfrm_input(skb, nexthdr, spi, encap_type);
67 	}
68 
69 	return -EINVAL;
70 drop:
71 	kfree_skb(skb);
72 	return 0;
73 }
74 
75 static int vti_input_proto(struct sk_buff *skb, int nexthdr, __be32 spi,
76 			   int encap_type)
77 {
78 	return vti_input(skb, nexthdr, spi, encap_type, false);
79 }
80 
81 static int vti_rcv(struct sk_buff *skb, __be32 spi, bool update_skb_dev)
82 {
83 	XFRM_SPI_SKB_CB(skb)->family = AF_INET;
84 	XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct iphdr, daddr);
85 
86 	return vti_input(skb, ip_hdr(skb)->protocol, spi, 0, update_skb_dev);
87 }
88 
89 static int vti_rcv_proto(struct sk_buff *skb)
90 {
91 	return vti_rcv(skb, 0, false);
92 }
93 
94 static int vti_rcv_tunnel(struct sk_buff *skb)
95 {
96 	return vti_rcv(skb, ip_hdr(skb)->saddr, true);
97 }
98 
99 static int vti_rcv_cb(struct sk_buff *skb, int err)
100 {
101 	unsigned short family;
102 	struct net_device *dev;
103 	struct pcpu_sw_netstats *tstats;
104 	struct xfrm_state *x;
105 	const struct xfrm_mode *inner_mode;
106 	struct ip_tunnel *tunnel = XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4;
107 	u32 orig_mark = skb->mark;
108 	int ret;
109 
110 	if (!tunnel)
111 		return 1;
112 
113 	dev = tunnel->dev;
114 
115 	if (err) {
116 		dev->stats.rx_errors++;
117 		dev->stats.rx_dropped++;
118 
119 		return 0;
120 	}
121 
122 	x = xfrm_input_state(skb);
123 
124 	inner_mode = &x->inner_mode;
125 
126 	if (x->sel.family == AF_UNSPEC) {
127 		inner_mode = xfrm_ip2inner_mode(x, XFRM_MODE_SKB_CB(skb)->protocol);
128 		if (inner_mode == NULL) {
129 			XFRM_INC_STATS(dev_net(skb->dev),
130 				       LINUX_MIB_XFRMINSTATEMODEERROR);
131 			return -EINVAL;
132 		}
133 	}
134 
135 	family = inner_mode->family;
136 
137 	skb->mark = be32_to_cpu(tunnel->parms.i_key);
138 	ret = xfrm_policy_check(NULL, XFRM_POLICY_IN, skb, family);
139 	skb->mark = orig_mark;
140 
141 	if (!ret)
142 		return -EPERM;
143 
144 	skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(skb->dev)));
145 	skb->dev = dev;
146 
147 	tstats = this_cpu_ptr(dev->tstats);
148 
149 	u64_stats_update_begin(&tstats->syncp);
150 	tstats->rx_packets++;
151 	tstats->rx_bytes += skb->len;
152 	u64_stats_update_end(&tstats->syncp);
153 
154 	return 0;
155 }
156 
157 static bool vti_state_check(const struct xfrm_state *x, __be32 dst, __be32 src)
158 {
159 	xfrm_address_t *daddr = (xfrm_address_t *)&dst;
160 	xfrm_address_t *saddr = (xfrm_address_t *)&src;
161 
162 	/* if there is no transform then this tunnel is not functional.
163 	 * Or if the xfrm is not mode tunnel.
164 	 */
165 	if (!x || x->props.mode != XFRM_MODE_TUNNEL ||
166 	    x->props.family != AF_INET)
167 		return false;
168 
169 	if (!dst)
170 		return xfrm_addr_equal(saddr, &x->props.saddr, AF_INET);
171 
172 	if (!xfrm_state_addr_check(x, daddr, saddr, AF_INET))
173 		return false;
174 
175 	return true;
176 }
177 
178 static netdev_tx_t vti_xmit(struct sk_buff *skb, struct net_device *dev,
179 			    struct flowi *fl)
180 {
181 	struct ip_tunnel *tunnel = netdev_priv(dev);
182 	struct ip_tunnel_parm *parms = &tunnel->parms;
183 	struct dst_entry *dst = skb_dst(skb);
184 	struct net_device *tdev;	/* Device to other host */
185 	int pkt_len = skb->len;
186 	int err;
187 	int mtu;
188 
189 	if (!dst) {
190 		switch (skb->protocol) {
191 		case htons(ETH_P_IP): {
192 			struct rtable *rt;
193 
194 			fl->u.ip4.flowi4_oif = dev->ifindex;
195 			fl->u.ip4.flowi4_flags |= FLOWI_FLAG_ANYSRC;
196 			rt = __ip_route_output_key(dev_net(dev), &fl->u.ip4);
197 			if (IS_ERR(rt)) {
198 				dev->stats.tx_carrier_errors++;
199 				goto tx_error_icmp;
200 			}
201 			dst = &rt->dst;
202 			skb_dst_set(skb, dst);
203 			break;
204 		}
205 #if IS_ENABLED(CONFIG_IPV6)
206 		case htons(ETH_P_IPV6):
207 			fl->u.ip6.flowi6_oif = dev->ifindex;
208 			fl->u.ip6.flowi6_flags |= FLOWI_FLAG_ANYSRC;
209 			dst = ip6_route_output(dev_net(dev), NULL, &fl->u.ip6);
210 			if (dst->error) {
211 				dst_release(dst);
212 				dst = NULL;
213 				dev->stats.tx_carrier_errors++;
214 				goto tx_error_icmp;
215 			}
216 			skb_dst_set(skb, dst);
217 			break;
218 #endif
219 		default:
220 			dev->stats.tx_carrier_errors++;
221 			goto tx_error_icmp;
222 		}
223 	}
224 
225 	dst_hold(dst);
226 	dst = xfrm_lookup(tunnel->net, dst, fl, NULL, 0);
227 	if (IS_ERR(dst)) {
228 		dev->stats.tx_carrier_errors++;
229 		goto tx_error_icmp;
230 	}
231 
232 	if (!vti_state_check(dst->xfrm, parms->iph.daddr, parms->iph.saddr)) {
233 		dev->stats.tx_carrier_errors++;
234 		dst_release(dst);
235 		goto tx_error_icmp;
236 	}
237 
238 	tdev = dst->dev;
239 
240 	if (tdev == dev) {
241 		dst_release(dst);
242 		dev->stats.collisions++;
243 		goto tx_error;
244 	}
245 
246 	mtu = dst_mtu(dst);
247 	if (skb->len > mtu) {
248 		skb_dst_update_pmtu_no_confirm(skb, mtu);
249 		if (skb->protocol == htons(ETH_P_IP)) {
250 			icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
251 				  htonl(mtu));
252 		} else {
253 			if (mtu < IPV6_MIN_MTU)
254 				mtu = IPV6_MIN_MTU;
255 
256 			icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
257 		}
258 
259 		dst_release(dst);
260 		goto tx_error;
261 	}
262 
263 	skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(dev)));
264 	skb_dst_set(skb, dst);
265 	skb->dev = skb_dst(skb)->dev;
266 
267 	err = dst_output(tunnel->net, skb->sk, skb);
268 	if (net_xmit_eval(err) == 0)
269 		err = pkt_len;
270 	iptunnel_xmit_stats(dev, err);
271 	return NETDEV_TX_OK;
272 
273 tx_error_icmp:
274 	dst_link_failure(skb);
275 tx_error:
276 	dev->stats.tx_errors++;
277 	kfree_skb(skb);
278 	return NETDEV_TX_OK;
279 }
280 
281 /* This function assumes it is being called from dev_queue_xmit()
282  * and that skb is filled properly by that function.
283  */
284 static netdev_tx_t vti_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
285 {
286 	struct ip_tunnel *tunnel = netdev_priv(dev);
287 	struct flowi fl;
288 
289 	if (!pskb_inet_may_pull(skb))
290 		goto tx_err;
291 
292 	memset(&fl, 0, sizeof(fl));
293 
294 	switch (skb->protocol) {
295 	case htons(ETH_P_IP):
296 		xfrm_decode_session(skb, &fl, AF_INET);
297 		memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
298 		break;
299 	case htons(ETH_P_IPV6):
300 		xfrm_decode_session(skb, &fl, AF_INET6);
301 		memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
302 		break;
303 	default:
304 		goto tx_err;
305 	}
306 
307 	/* override mark with tunnel output key */
308 	fl.flowi_mark = be32_to_cpu(tunnel->parms.o_key);
309 
310 	return vti_xmit(skb, dev, &fl);
311 
312 tx_err:
313 	dev->stats.tx_errors++;
314 	kfree_skb(skb);
315 	return NETDEV_TX_OK;
316 }
317 
318 static int vti4_err(struct sk_buff *skb, u32 info)
319 {
320 	__be32 spi;
321 	__u32 mark;
322 	struct xfrm_state *x;
323 	struct ip_tunnel *tunnel;
324 	struct ip_esp_hdr *esph;
325 	struct ip_auth_hdr *ah ;
326 	struct ip_comp_hdr *ipch;
327 	struct net *net = dev_net(skb->dev);
328 	const struct iphdr *iph = (const struct iphdr *)skb->data;
329 	int protocol = iph->protocol;
330 	struct ip_tunnel_net *itn = net_generic(net, vti_net_id);
331 
332 	tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY,
333 				  iph->daddr, iph->saddr, 0);
334 	if (!tunnel)
335 		return -1;
336 
337 	mark = be32_to_cpu(tunnel->parms.o_key);
338 
339 	switch (protocol) {
340 	case IPPROTO_ESP:
341 		esph = (struct ip_esp_hdr *)(skb->data+(iph->ihl<<2));
342 		spi = esph->spi;
343 		break;
344 	case IPPROTO_AH:
345 		ah = (struct ip_auth_hdr *)(skb->data+(iph->ihl<<2));
346 		spi = ah->spi;
347 		break;
348 	case IPPROTO_COMP:
349 		ipch = (struct ip_comp_hdr *)(skb->data+(iph->ihl<<2));
350 		spi = htonl(ntohs(ipch->cpi));
351 		break;
352 	default:
353 		return 0;
354 	}
355 
356 	switch (icmp_hdr(skb)->type) {
357 	case ICMP_DEST_UNREACH:
358 		if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
359 			return 0;
360 	case ICMP_REDIRECT:
361 		break;
362 	default:
363 		return 0;
364 	}
365 
366 	x = xfrm_state_lookup(net, mark, (const xfrm_address_t *)&iph->daddr,
367 			      spi, protocol, AF_INET);
368 	if (!x)
369 		return 0;
370 
371 	if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH)
372 		ipv4_update_pmtu(skb, net, info, 0, protocol);
373 	else
374 		ipv4_redirect(skb, net, 0, protocol);
375 	xfrm_state_put(x);
376 
377 	return 0;
378 }
379 
380 static int
381 vti_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
382 {
383 	int err = 0;
384 	struct ip_tunnel_parm p;
385 
386 	if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
387 		return -EFAULT;
388 
389 	if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) {
390 		if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPIP ||
391 		    p.iph.ihl != 5)
392 			return -EINVAL;
393 	}
394 
395 	if (!(p.i_flags & GRE_KEY))
396 		p.i_key = 0;
397 	if (!(p.o_flags & GRE_KEY))
398 		p.o_key = 0;
399 
400 	p.i_flags = VTI_ISVTI;
401 
402 	err = ip_tunnel_ioctl(dev, &p, cmd);
403 	if (err)
404 		return err;
405 
406 	if (cmd != SIOCDELTUNNEL) {
407 		p.i_flags |= GRE_KEY;
408 		p.o_flags |= GRE_KEY;
409 	}
410 
411 	if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
412 		return -EFAULT;
413 	return 0;
414 }
415 
416 static const struct net_device_ops vti_netdev_ops = {
417 	.ndo_init	= vti_tunnel_init,
418 	.ndo_uninit	= ip_tunnel_uninit,
419 	.ndo_start_xmit	= vti_tunnel_xmit,
420 	.ndo_do_ioctl	= vti_tunnel_ioctl,
421 	.ndo_change_mtu	= ip_tunnel_change_mtu,
422 	.ndo_get_stats64 = ip_tunnel_get_stats64,
423 	.ndo_get_iflink = ip_tunnel_get_iflink,
424 };
425 
426 static void vti_tunnel_setup(struct net_device *dev)
427 {
428 	dev->netdev_ops		= &vti_netdev_ops;
429 	dev->type		= ARPHRD_TUNNEL;
430 	ip_tunnel_setup(dev, vti_net_id);
431 }
432 
433 static int vti_tunnel_init(struct net_device *dev)
434 {
435 	struct ip_tunnel *tunnel = netdev_priv(dev);
436 	struct iphdr *iph = &tunnel->parms.iph;
437 
438 	memcpy(dev->dev_addr, &iph->saddr, 4);
439 	memcpy(dev->broadcast, &iph->daddr, 4);
440 
441 	dev->flags		= IFF_NOARP;
442 	dev->addr_len		= 4;
443 	dev->features		|= NETIF_F_LLTX;
444 	netif_keep_dst(dev);
445 
446 	return ip_tunnel_init(dev);
447 }
448 
449 static void __net_init vti_fb_tunnel_init(struct net_device *dev)
450 {
451 	struct ip_tunnel *tunnel = netdev_priv(dev);
452 	struct iphdr *iph = &tunnel->parms.iph;
453 
454 	iph->version		= 4;
455 	iph->protocol		= IPPROTO_IPIP;
456 	iph->ihl		= 5;
457 }
458 
459 static struct xfrm4_protocol vti_esp4_protocol __read_mostly = {
460 	.handler	=	vti_rcv_proto,
461 	.input_handler	=	vti_input_proto,
462 	.cb_handler	=	vti_rcv_cb,
463 	.err_handler	=	vti4_err,
464 	.priority	=	100,
465 };
466 
467 static struct xfrm4_protocol vti_ah4_protocol __read_mostly = {
468 	.handler	=	vti_rcv_proto,
469 	.input_handler	=	vti_input_proto,
470 	.cb_handler	=	vti_rcv_cb,
471 	.err_handler	=	vti4_err,
472 	.priority	=	100,
473 };
474 
475 static struct xfrm4_protocol vti_ipcomp4_protocol __read_mostly = {
476 	.handler	=	vti_rcv_proto,
477 	.input_handler	=	vti_input_proto,
478 	.cb_handler	=	vti_rcv_cb,
479 	.err_handler	=	vti4_err,
480 	.priority	=	100,
481 };
482 
483 static struct xfrm_tunnel ipip_handler __read_mostly = {
484 	.handler	=	vti_rcv_tunnel,
485 	.err_handler	=	vti4_err,
486 	.priority	=	0,
487 };
488 
489 static int __net_init vti_init_net(struct net *net)
490 {
491 	int err;
492 	struct ip_tunnel_net *itn;
493 
494 	err = ip_tunnel_init_net(net, vti_net_id, &vti_link_ops, "ip_vti0");
495 	if (err)
496 		return err;
497 	itn = net_generic(net, vti_net_id);
498 	if (itn->fb_tunnel_dev)
499 		vti_fb_tunnel_init(itn->fb_tunnel_dev);
500 	return 0;
501 }
502 
503 static void __net_exit vti_exit_batch_net(struct list_head *list_net)
504 {
505 	ip_tunnel_delete_nets(list_net, vti_net_id, &vti_link_ops);
506 }
507 
508 static struct pernet_operations vti_net_ops = {
509 	.init = vti_init_net,
510 	.exit_batch = vti_exit_batch_net,
511 	.id   = &vti_net_id,
512 	.size = sizeof(struct ip_tunnel_net),
513 };
514 
515 static int vti_tunnel_validate(struct nlattr *tb[], struct nlattr *data[],
516 			       struct netlink_ext_ack *extack)
517 {
518 	return 0;
519 }
520 
521 static void vti_netlink_parms(struct nlattr *data[],
522 			      struct ip_tunnel_parm *parms,
523 			      __u32 *fwmark)
524 {
525 	memset(parms, 0, sizeof(*parms));
526 
527 	parms->iph.protocol = IPPROTO_IPIP;
528 
529 	if (!data)
530 		return;
531 
532 	parms->i_flags = VTI_ISVTI;
533 
534 	if (data[IFLA_VTI_LINK])
535 		parms->link = nla_get_u32(data[IFLA_VTI_LINK]);
536 
537 	if (data[IFLA_VTI_IKEY])
538 		parms->i_key = nla_get_be32(data[IFLA_VTI_IKEY]);
539 
540 	if (data[IFLA_VTI_OKEY])
541 		parms->o_key = nla_get_be32(data[IFLA_VTI_OKEY]);
542 
543 	if (data[IFLA_VTI_LOCAL])
544 		parms->iph.saddr = nla_get_in_addr(data[IFLA_VTI_LOCAL]);
545 
546 	if (data[IFLA_VTI_REMOTE])
547 		parms->iph.daddr = nla_get_in_addr(data[IFLA_VTI_REMOTE]);
548 
549 	if (data[IFLA_VTI_FWMARK])
550 		*fwmark = nla_get_u32(data[IFLA_VTI_FWMARK]);
551 }
552 
553 static int vti_newlink(struct net *src_net, struct net_device *dev,
554 		       struct nlattr *tb[], struct nlattr *data[],
555 		       struct netlink_ext_ack *extack)
556 {
557 	struct ip_tunnel_parm parms;
558 	__u32 fwmark = 0;
559 
560 	vti_netlink_parms(data, &parms, &fwmark);
561 	return ip_tunnel_newlink(dev, tb, &parms, fwmark);
562 }
563 
564 static int vti_changelink(struct net_device *dev, struct nlattr *tb[],
565 			  struct nlattr *data[],
566 			  struct netlink_ext_ack *extack)
567 {
568 	struct ip_tunnel *t = netdev_priv(dev);
569 	__u32 fwmark = t->fwmark;
570 	struct ip_tunnel_parm p;
571 
572 	vti_netlink_parms(data, &p, &fwmark);
573 	return ip_tunnel_changelink(dev, tb, &p, fwmark);
574 }
575 
576 static size_t vti_get_size(const struct net_device *dev)
577 {
578 	return
579 		/* IFLA_VTI_LINK */
580 		nla_total_size(4) +
581 		/* IFLA_VTI_IKEY */
582 		nla_total_size(4) +
583 		/* IFLA_VTI_OKEY */
584 		nla_total_size(4) +
585 		/* IFLA_VTI_LOCAL */
586 		nla_total_size(4) +
587 		/* IFLA_VTI_REMOTE */
588 		nla_total_size(4) +
589 		/* IFLA_VTI_FWMARK */
590 		nla_total_size(4) +
591 		0;
592 }
593 
594 static int vti_fill_info(struct sk_buff *skb, const struct net_device *dev)
595 {
596 	struct ip_tunnel *t = netdev_priv(dev);
597 	struct ip_tunnel_parm *p = &t->parms;
598 
599 	if (nla_put_u32(skb, IFLA_VTI_LINK, p->link) ||
600 	    nla_put_be32(skb, IFLA_VTI_IKEY, p->i_key) ||
601 	    nla_put_be32(skb, IFLA_VTI_OKEY, p->o_key) ||
602 	    nla_put_in_addr(skb, IFLA_VTI_LOCAL, p->iph.saddr) ||
603 	    nla_put_in_addr(skb, IFLA_VTI_REMOTE, p->iph.daddr) ||
604 	    nla_put_u32(skb, IFLA_VTI_FWMARK, t->fwmark))
605 		return -EMSGSIZE;
606 
607 	return 0;
608 }
609 
610 static const struct nla_policy vti_policy[IFLA_VTI_MAX + 1] = {
611 	[IFLA_VTI_LINK]		= { .type = NLA_U32 },
612 	[IFLA_VTI_IKEY]		= { .type = NLA_U32 },
613 	[IFLA_VTI_OKEY]		= { .type = NLA_U32 },
614 	[IFLA_VTI_LOCAL]	= { .len = sizeof_field(struct iphdr, saddr) },
615 	[IFLA_VTI_REMOTE]	= { .len = sizeof_field(struct iphdr, daddr) },
616 	[IFLA_VTI_FWMARK]	= { .type = NLA_U32 },
617 };
618 
619 static struct rtnl_link_ops vti_link_ops __read_mostly = {
620 	.kind		= "vti",
621 	.maxtype	= IFLA_VTI_MAX,
622 	.policy		= vti_policy,
623 	.priv_size	= sizeof(struct ip_tunnel),
624 	.setup		= vti_tunnel_setup,
625 	.validate	= vti_tunnel_validate,
626 	.newlink	= vti_newlink,
627 	.changelink	= vti_changelink,
628 	.dellink        = ip_tunnel_dellink,
629 	.get_size	= vti_get_size,
630 	.fill_info	= vti_fill_info,
631 	.get_link_net	= ip_tunnel_get_link_net,
632 };
633 
634 static int __init vti_init(void)
635 {
636 	const char *msg;
637 	int err;
638 
639 	pr_info("IPv4 over IPsec tunneling driver\n");
640 
641 	msg = "tunnel device";
642 	err = register_pernet_device(&vti_net_ops);
643 	if (err < 0)
644 		goto pernet_dev_failed;
645 
646 	msg = "tunnel protocols";
647 	err = xfrm4_protocol_register(&vti_esp4_protocol, IPPROTO_ESP);
648 	if (err < 0)
649 		goto xfrm_proto_esp_failed;
650 	err = xfrm4_protocol_register(&vti_ah4_protocol, IPPROTO_AH);
651 	if (err < 0)
652 		goto xfrm_proto_ah_failed;
653 	err = xfrm4_protocol_register(&vti_ipcomp4_protocol, IPPROTO_COMP);
654 	if (err < 0)
655 		goto xfrm_proto_comp_failed;
656 
657 	msg = "ipip tunnel";
658 	err = xfrm4_tunnel_register(&ipip_handler, AF_INET);
659 	if (err < 0)
660 		goto xfrm_tunnel_failed;
661 
662 	msg = "netlink interface";
663 	err = rtnl_link_register(&vti_link_ops);
664 	if (err < 0)
665 		goto rtnl_link_failed;
666 
667 	return err;
668 
669 rtnl_link_failed:
670 	xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
671 xfrm_tunnel_failed:
672 	xfrm4_protocol_deregister(&vti_ipcomp4_protocol, IPPROTO_COMP);
673 xfrm_proto_comp_failed:
674 	xfrm4_protocol_deregister(&vti_ah4_protocol, IPPROTO_AH);
675 xfrm_proto_ah_failed:
676 	xfrm4_protocol_deregister(&vti_esp4_protocol, IPPROTO_ESP);
677 xfrm_proto_esp_failed:
678 	unregister_pernet_device(&vti_net_ops);
679 pernet_dev_failed:
680 	pr_err("vti init: failed to register %s\n", msg);
681 	return err;
682 }
683 
684 static void __exit vti_fini(void)
685 {
686 	rtnl_link_unregister(&vti_link_ops);
687 	xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
688 	xfrm4_protocol_deregister(&vti_ipcomp4_protocol, IPPROTO_COMP);
689 	xfrm4_protocol_deregister(&vti_ah4_protocol, IPPROTO_AH);
690 	xfrm4_protocol_deregister(&vti_esp4_protocol, IPPROTO_ESP);
691 	unregister_pernet_device(&vti_net_ops);
692 }
693 
694 module_init(vti_init);
695 module_exit(vti_fini);
696 MODULE_LICENSE("GPL");
697 MODULE_ALIAS_RTNL_LINK("vti");
698 MODULE_ALIAS_NETDEV("ip_vti0");
699