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 
vti_input(struct sk_buff * skb,int nexthdr,__be32 spi,int encap_type)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 
vti_rcv(struct sk_buff * skb)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 
vti_rcv_cb(struct sk_buff * skb,int err)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 
vti_state_check(const struct xfrm_state * x,__be32 dst,__be32 src)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 
vti_xmit(struct sk_buff * skb,struct net_device * dev,struct flowi * fl)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 	mtu = dst_mtu(dst);
202 	if (skb->len > mtu) {
203 		skb_dst_update_pmtu(skb, mtu);
204 		if (skb->protocol == htons(ETH_P_IP)) {
205 			icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
206 				  htonl(mtu));
207 		} else {
208 			if (mtu < IPV6_MIN_MTU)
209 				mtu = IPV6_MIN_MTU;
210 
211 			icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
212 		}
213 
214 		dst_release(dst);
215 		goto tx_error;
216 	}
217 
218 	skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(dev)));
219 	skb_dst_set(skb, dst);
220 	skb->dev = skb_dst(skb)->dev;
221 
222 	err = dst_output(tunnel->net, skb->sk, skb);
223 	if (net_xmit_eval(err) == 0)
224 		err = pkt_len;
225 	iptunnel_xmit_stats(dev, err);
226 	return NETDEV_TX_OK;
227 
228 tx_error_icmp:
229 	dst_link_failure(skb);
230 tx_error:
231 	dev->stats.tx_errors++;
232 	kfree_skb(skb);
233 	return NETDEV_TX_OK;
234 }
235 
236 /* This function assumes it is being called from dev_queue_xmit()
237  * and that skb is filled properly by that function.
238  */
vti_tunnel_xmit(struct sk_buff * skb,struct net_device * dev)239 static netdev_tx_t vti_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
240 {
241 	struct ip_tunnel *tunnel = netdev_priv(dev);
242 	struct flowi fl;
243 
244 	memset(&fl, 0, sizeof(fl));
245 
246 	switch (skb->protocol) {
247 	case htons(ETH_P_IP):
248 		xfrm_decode_session(skb, &fl, AF_INET);
249 		memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
250 		break;
251 	case htons(ETH_P_IPV6):
252 		xfrm_decode_session(skb, &fl, AF_INET6);
253 		memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
254 		break;
255 	default:
256 		dev->stats.tx_errors++;
257 		dev_kfree_skb(skb);
258 		return NETDEV_TX_OK;
259 	}
260 
261 	/* override mark with tunnel output key */
262 	fl.flowi_mark = be32_to_cpu(tunnel->parms.o_key);
263 
264 	return vti_xmit(skb, dev, &fl);
265 }
266 
vti4_err(struct sk_buff * skb,u32 info)267 static int vti4_err(struct sk_buff *skb, u32 info)
268 {
269 	__be32 spi;
270 	__u32 mark;
271 	struct xfrm_state *x;
272 	struct ip_tunnel *tunnel;
273 	struct ip_esp_hdr *esph;
274 	struct ip_auth_hdr *ah ;
275 	struct ip_comp_hdr *ipch;
276 	struct net *net = dev_net(skb->dev);
277 	const struct iphdr *iph = (const struct iphdr *)skb->data;
278 	int protocol = iph->protocol;
279 	struct ip_tunnel_net *itn = net_generic(net, vti_net_id);
280 
281 	tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY,
282 				  iph->daddr, iph->saddr, 0);
283 	if (!tunnel)
284 		return -1;
285 
286 	mark = be32_to_cpu(tunnel->parms.o_key);
287 
288 	switch (protocol) {
289 	case IPPROTO_ESP:
290 		esph = (struct ip_esp_hdr *)(skb->data+(iph->ihl<<2));
291 		spi = esph->spi;
292 		break;
293 	case IPPROTO_AH:
294 		ah = (struct ip_auth_hdr *)(skb->data+(iph->ihl<<2));
295 		spi = ah->spi;
296 		break;
297 	case IPPROTO_COMP:
298 		ipch = (struct ip_comp_hdr *)(skb->data+(iph->ihl<<2));
299 		spi = htonl(ntohs(ipch->cpi));
300 		break;
301 	default:
302 		return 0;
303 	}
304 
305 	switch (icmp_hdr(skb)->type) {
306 	case ICMP_DEST_UNREACH:
307 		if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
308 			return 0;
309 	case ICMP_REDIRECT:
310 		break;
311 	default:
312 		return 0;
313 	}
314 
315 	x = xfrm_state_lookup(net, mark, (const xfrm_address_t *)&iph->daddr,
316 			      spi, protocol, AF_INET);
317 	if (!x)
318 		return 0;
319 
320 	if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH)
321 		ipv4_update_pmtu(skb, net, info, 0, 0, protocol, 0);
322 	else
323 		ipv4_redirect(skb, net, 0, 0, protocol, 0);
324 	xfrm_state_put(x);
325 
326 	return 0;
327 }
328 
329 static int
vti_tunnel_ioctl(struct net_device * dev,struct ifreq * ifr,int cmd)330 vti_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
331 {
332 	int err = 0;
333 	struct ip_tunnel_parm p;
334 
335 	if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
336 		return -EFAULT;
337 
338 	if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) {
339 		if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPIP ||
340 		    p.iph.ihl != 5)
341 			return -EINVAL;
342 	}
343 
344 	if (!(p.i_flags & GRE_KEY))
345 		p.i_key = 0;
346 	if (!(p.o_flags & GRE_KEY))
347 		p.o_key = 0;
348 
349 	p.i_flags = VTI_ISVTI;
350 
351 	err = ip_tunnel_ioctl(dev, &p, cmd);
352 	if (err)
353 		return err;
354 
355 	if (cmd != SIOCDELTUNNEL) {
356 		p.i_flags |= GRE_KEY;
357 		p.o_flags |= GRE_KEY;
358 	}
359 
360 	if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
361 		return -EFAULT;
362 	return 0;
363 }
364 
365 static const struct net_device_ops vti_netdev_ops = {
366 	.ndo_init	= vti_tunnel_init,
367 	.ndo_uninit	= ip_tunnel_uninit,
368 	.ndo_start_xmit	= vti_tunnel_xmit,
369 	.ndo_do_ioctl	= vti_tunnel_ioctl,
370 	.ndo_change_mtu	= ip_tunnel_change_mtu,
371 	.ndo_get_stats64 = ip_tunnel_get_stats64,
372 	.ndo_get_iflink = ip_tunnel_get_iflink,
373 };
374 
vti_tunnel_setup(struct net_device * dev)375 static void vti_tunnel_setup(struct net_device *dev)
376 {
377 	dev->netdev_ops		= &vti_netdev_ops;
378 	dev->type		= ARPHRD_TUNNEL;
379 	ip_tunnel_setup(dev, vti_net_id);
380 }
381 
vti_tunnel_init(struct net_device * dev)382 static int vti_tunnel_init(struct net_device *dev)
383 {
384 	struct ip_tunnel *tunnel = netdev_priv(dev);
385 	struct iphdr *iph = &tunnel->parms.iph;
386 
387 	memcpy(dev->dev_addr, &iph->saddr, 4);
388 	memcpy(dev->broadcast, &iph->daddr, 4);
389 
390 	dev->flags		= IFF_NOARP;
391 	dev->addr_len		= 4;
392 	dev->features		|= NETIF_F_LLTX;
393 	netif_keep_dst(dev);
394 
395 	return ip_tunnel_init(dev);
396 }
397 
vti_fb_tunnel_init(struct net_device * dev)398 static void __net_init vti_fb_tunnel_init(struct net_device *dev)
399 {
400 	struct ip_tunnel *tunnel = netdev_priv(dev);
401 	struct iphdr *iph = &tunnel->parms.iph;
402 
403 	iph->version		= 4;
404 	iph->protocol		= IPPROTO_IPIP;
405 	iph->ihl		= 5;
406 }
407 
408 static struct xfrm4_protocol vti_esp4_protocol __read_mostly = {
409 	.handler	=	vti_rcv,
410 	.input_handler	=	vti_input,
411 	.cb_handler	=	vti_rcv_cb,
412 	.err_handler	=	vti4_err,
413 	.priority	=	100,
414 };
415 
416 static struct xfrm4_protocol vti_ah4_protocol __read_mostly = {
417 	.handler	=	vti_rcv,
418 	.input_handler	=	vti_input,
419 	.cb_handler	=	vti_rcv_cb,
420 	.err_handler	=	vti4_err,
421 	.priority	=	100,
422 };
423 
424 static struct xfrm4_protocol vti_ipcomp4_protocol __read_mostly = {
425 	.handler	=	vti_rcv,
426 	.input_handler	=	vti_input,
427 	.cb_handler	=	vti_rcv_cb,
428 	.err_handler	=	vti4_err,
429 	.priority	=	100,
430 };
431 
vti_init_net(struct net * net)432 static int __net_init vti_init_net(struct net *net)
433 {
434 	int err;
435 	struct ip_tunnel_net *itn;
436 
437 	err = ip_tunnel_init_net(net, vti_net_id, &vti_link_ops, "ip_vti0");
438 	if (err)
439 		return err;
440 	itn = net_generic(net, vti_net_id);
441 	if (itn->fb_tunnel_dev)
442 		vti_fb_tunnel_init(itn->fb_tunnel_dev);
443 	return 0;
444 }
445 
vti_exit_batch_net(struct list_head * list_net)446 static void __net_exit vti_exit_batch_net(struct list_head *list_net)
447 {
448 	ip_tunnel_delete_nets(list_net, vti_net_id, &vti_link_ops);
449 }
450 
451 static struct pernet_operations vti_net_ops = {
452 	.init = vti_init_net,
453 	.exit_batch = vti_exit_batch_net,
454 	.id   = &vti_net_id,
455 	.size = sizeof(struct ip_tunnel_net),
456 };
457 
vti_tunnel_validate(struct nlattr * tb[],struct nlattr * data[],struct netlink_ext_ack * extack)458 static int vti_tunnel_validate(struct nlattr *tb[], struct nlattr *data[],
459 			       struct netlink_ext_ack *extack)
460 {
461 	return 0;
462 }
463 
vti_netlink_parms(struct nlattr * data[],struct ip_tunnel_parm * parms,__u32 * fwmark)464 static void vti_netlink_parms(struct nlattr *data[],
465 			      struct ip_tunnel_parm *parms,
466 			      __u32 *fwmark)
467 {
468 	memset(parms, 0, sizeof(*parms));
469 
470 	parms->iph.protocol = IPPROTO_IPIP;
471 
472 	if (!data)
473 		return;
474 
475 	parms->i_flags = VTI_ISVTI;
476 
477 	if (data[IFLA_VTI_LINK])
478 		parms->link = nla_get_u32(data[IFLA_VTI_LINK]);
479 
480 	if (data[IFLA_VTI_IKEY])
481 		parms->i_key = nla_get_be32(data[IFLA_VTI_IKEY]);
482 
483 	if (data[IFLA_VTI_OKEY])
484 		parms->o_key = nla_get_be32(data[IFLA_VTI_OKEY]);
485 
486 	if (data[IFLA_VTI_LOCAL])
487 		parms->iph.saddr = nla_get_in_addr(data[IFLA_VTI_LOCAL]);
488 
489 	if (data[IFLA_VTI_REMOTE])
490 		parms->iph.daddr = nla_get_in_addr(data[IFLA_VTI_REMOTE]);
491 
492 	if (data[IFLA_VTI_FWMARK])
493 		*fwmark = nla_get_u32(data[IFLA_VTI_FWMARK]);
494 }
495 
vti_newlink(struct net * src_net,struct net_device * dev,struct nlattr * tb[],struct nlattr * data[],struct netlink_ext_ack * extack)496 static int vti_newlink(struct net *src_net, struct net_device *dev,
497 		       struct nlattr *tb[], struct nlattr *data[],
498 		       struct netlink_ext_ack *extack)
499 {
500 	struct ip_tunnel_parm parms;
501 	__u32 fwmark = 0;
502 
503 	vti_netlink_parms(data, &parms, &fwmark);
504 	return ip_tunnel_newlink(dev, tb, &parms, fwmark);
505 }
506 
vti_changelink(struct net_device * dev,struct nlattr * tb[],struct nlattr * data[],struct netlink_ext_ack * extack)507 static int vti_changelink(struct net_device *dev, struct nlattr *tb[],
508 			  struct nlattr *data[],
509 			  struct netlink_ext_ack *extack)
510 {
511 	struct ip_tunnel *t = netdev_priv(dev);
512 	__u32 fwmark = t->fwmark;
513 	struct ip_tunnel_parm p;
514 
515 	vti_netlink_parms(data, &p, &fwmark);
516 	return ip_tunnel_changelink(dev, tb, &p, fwmark);
517 }
518 
vti_get_size(const struct net_device * dev)519 static size_t vti_get_size(const struct net_device *dev)
520 {
521 	return
522 		/* IFLA_VTI_LINK */
523 		nla_total_size(4) +
524 		/* IFLA_VTI_IKEY */
525 		nla_total_size(4) +
526 		/* IFLA_VTI_OKEY */
527 		nla_total_size(4) +
528 		/* IFLA_VTI_LOCAL */
529 		nla_total_size(4) +
530 		/* IFLA_VTI_REMOTE */
531 		nla_total_size(4) +
532 		/* IFLA_VTI_FWMARK */
533 		nla_total_size(4) +
534 		0;
535 }
536 
vti_fill_info(struct sk_buff * skb,const struct net_device * dev)537 static int vti_fill_info(struct sk_buff *skb, const struct net_device *dev)
538 {
539 	struct ip_tunnel *t = netdev_priv(dev);
540 	struct ip_tunnel_parm *p = &t->parms;
541 
542 	if (nla_put_u32(skb, IFLA_VTI_LINK, p->link) ||
543 	    nla_put_be32(skb, IFLA_VTI_IKEY, p->i_key) ||
544 	    nla_put_be32(skb, IFLA_VTI_OKEY, p->o_key) ||
545 	    nla_put_in_addr(skb, IFLA_VTI_LOCAL, p->iph.saddr) ||
546 	    nla_put_in_addr(skb, IFLA_VTI_REMOTE, p->iph.daddr) ||
547 	    nla_put_u32(skb, IFLA_VTI_FWMARK, t->fwmark))
548 		return -EMSGSIZE;
549 
550 	return 0;
551 }
552 
553 static const struct nla_policy vti_policy[IFLA_VTI_MAX + 1] = {
554 	[IFLA_VTI_LINK]		= { .type = NLA_U32 },
555 	[IFLA_VTI_IKEY]		= { .type = NLA_U32 },
556 	[IFLA_VTI_OKEY]		= { .type = NLA_U32 },
557 	[IFLA_VTI_LOCAL]	= { .len = FIELD_SIZEOF(struct iphdr, saddr) },
558 	[IFLA_VTI_REMOTE]	= { .len = FIELD_SIZEOF(struct iphdr, daddr) },
559 	[IFLA_VTI_FWMARK]	= { .type = NLA_U32 },
560 };
561 
562 static struct rtnl_link_ops vti_link_ops __read_mostly = {
563 	.kind		= "vti",
564 	.maxtype	= IFLA_VTI_MAX,
565 	.policy		= vti_policy,
566 	.priv_size	= sizeof(struct ip_tunnel),
567 	.setup		= vti_tunnel_setup,
568 	.validate	= vti_tunnel_validate,
569 	.newlink	= vti_newlink,
570 	.changelink	= vti_changelink,
571 	.dellink        = ip_tunnel_dellink,
572 	.get_size	= vti_get_size,
573 	.fill_info	= vti_fill_info,
574 	.get_link_net	= ip_tunnel_get_link_net,
575 };
576 
vti_init(void)577 static int __init vti_init(void)
578 {
579 	const char *msg;
580 	int err;
581 
582 	pr_info("IPv4 over IPsec tunneling driver\n");
583 
584 	msg = "tunnel device";
585 	err = register_pernet_device(&vti_net_ops);
586 	if (err < 0)
587 		goto pernet_dev_failed;
588 
589 	msg = "tunnel protocols";
590 	err = xfrm4_protocol_register(&vti_esp4_protocol, IPPROTO_ESP);
591 	if (err < 0)
592 		goto xfrm_proto_esp_failed;
593 	err = xfrm4_protocol_register(&vti_ah4_protocol, IPPROTO_AH);
594 	if (err < 0)
595 		goto xfrm_proto_ah_failed;
596 	err = xfrm4_protocol_register(&vti_ipcomp4_protocol, IPPROTO_COMP);
597 	if (err < 0)
598 		goto xfrm_proto_comp_failed;
599 
600 	msg = "netlink interface";
601 	err = rtnl_link_register(&vti_link_ops);
602 	if (err < 0)
603 		goto rtnl_link_failed;
604 
605 	return err;
606 
607 rtnl_link_failed:
608 	xfrm4_protocol_deregister(&vti_ipcomp4_protocol, IPPROTO_COMP);
609 xfrm_proto_comp_failed:
610 	xfrm4_protocol_deregister(&vti_ah4_protocol, IPPROTO_AH);
611 xfrm_proto_ah_failed:
612 	xfrm4_protocol_deregister(&vti_esp4_protocol, IPPROTO_ESP);
613 xfrm_proto_esp_failed:
614 	unregister_pernet_device(&vti_net_ops);
615 pernet_dev_failed:
616 	pr_err("vti init: failed to register %s\n", msg);
617 	return err;
618 }
619 
vti_fini(void)620 static void __exit vti_fini(void)
621 {
622 	rtnl_link_unregister(&vti_link_ops);
623 	xfrm4_protocol_deregister(&vti_ipcomp4_protocol, IPPROTO_COMP);
624 	xfrm4_protocol_deregister(&vti_ah4_protocol, IPPROTO_AH);
625 	xfrm4_protocol_deregister(&vti_esp4_protocol, IPPROTO_ESP);
626 	unregister_pernet_device(&vti_net_ops);
627 }
628 
629 module_init(vti_init);
630 module_exit(vti_fini);
631 MODULE_LICENSE("GPL");
632 MODULE_ALIAS_RTNL_LINK("vti");
633 MODULE_ALIAS_NETDEV("ip_vti0");
634