xref: /openbmc/linux/net/ipv4/ip_vti.c (revision 11a163f2)
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_cb(struct sk_buff *skb, int err)
95 {
96 	unsigned short family;
97 	struct net_device *dev;
98 	struct xfrm_state *x;
99 	const struct xfrm_mode *inner_mode;
100 	struct ip_tunnel *tunnel = XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4;
101 	u32 orig_mark = skb->mark;
102 	int ret;
103 
104 	if (!tunnel)
105 		return 1;
106 
107 	dev = tunnel->dev;
108 
109 	if (err) {
110 		dev->stats.rx_errors++;
111 		dev->stats.rx_dropped++;
112 
113 		return 0;
114 	}
115 
116 	x = xfrm_input_state(skb);
117 
118 	inner_mode = &x->inner_mode;
119 
120 	if (x->sel.family == AF_UNSPEC) {
121 		inner_mode = xfrm_ip2inner_mode(x, XFRM_MODE_SKB_CB(skb)->protocol);
122 		if (inner_mode == NULL) {
123 			XFRM_INC_STATS(dev_net(skb->dev),
124 				       LINUX_MIB_XFRMINSTATEMODEERROR);
125 			return -EINVAL;
126 		}
127 	}
128 
129 	family = inner_mode->family;
130 
131 	skb->mark = be32_to_cpu(tunnel->parms.i_key);
132 	ret = xfrm_policy_check(NULL, XFRM_POLICY_IN, skb, family);
133 	skb->mark = orig_mark;
134 
135 	if (!ret)
136 		return -EPERM;
137 
138 	skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(skb->dev)));
139 	skb->dev = dev;
140 	dev_sw_netstats_rx_add(dev, skb->len);
141 
142 	return 0;
143 }
144 
145 static bool vti_state_check(const struct xfrm_state *x, __be32 dst, __be32 src)
146 {
147 	xfrm_address_t *daddr = (xfrm_address_t *)&dst;
148 	xfrm_address_t *saddr = (xfrm_address_t *)&src;
149 
150 	/* if there is no transform then this tunnel is not functional.
151 	 * Or if the xfrm is not mode tunnel.
152 	 */
153 	if (!x || x->props.mode != XFRM_MODE_TUNNEL ||
154 	    x->props.family != AF_INET)
155 		return false;
156 
157 	if (!dst)
158 		return xfrm_addr_equal(saddr, &x->props.saddr, AF_INET);
159 
160 	if (!xfrm_state_addr_check(x, daddr, saddr, AF_INET))
161 		return false;
162 
163 	return true;
164 }
165 
166 static netdev_tx_t vti_xmit(struct sk_buff *skb, struct net_device *dev,
167 			    struct flowi *fl)
168 {
169 	struct ip_tunnel *tunnel = netdev_priv(dev);
170 	struct ip_tunnel_parm *parms = &tunnel->parms;
171 	struct dst_entry *dst = skb_dst(skb);
172 	struct net_device *tdev;	/* Device to other host */
173 	int pkt_len = skb->len;
174 	int err;
175 	int mtu;
176 
177 	if (!dst) {
178 		switch (skb->protocol) {
179 		case htons(ETH_P_IP): {
180 			struct rtable *rt;
181 
182 			fl->u.ip4.flowi4_oif = dev->ifindex;
183 			fl->u.ip4.flowi4_flags |= FLOWI_FLAG_ANYSRC;
184 			rt = __ip_route_output_key(dev_net(dev), &fl->u.ip4);
185 			if (IS_ERR(rt)) {
186 				dev->stats.tx_carrier_errors++;
187 				goto tx_error_icmp;
188 			}
189 			dst = &rt->dst;
190 			skb_dst_set(skb, dst);
191 			break;
192 		}
193 #if IS_ENABLED(CONFIG_IPV6)
194 		case htons(ETH_P_IPV6):
195 			fl->u.ip6.flowi6_oif = dev->ifindex;
196 			fl->u.ip6.flowi6_flags |= FLOWI_FLAG_ANYSRC;
197 			dst = ip6_route_output(dev_net(dev), NULL, &fl->u.ip6);
198 			if (dst->error) {
199 				dst_release(dst);
200 				dst = NULL;
201 				dev->stats.tx_carrier_errors++;
202 				goto tx_error_icmp;
203 			}
204 			skb_dst_set(skb, dst);
205 			break;
206 #endif
207 		default:
208 			dev->stats.tx_carrier_errors++;
209 			goto tx_error_icmp;
210 		}
211 	}
212 
213 	dst_hold(dst);
214 	dst = xfrm_lookup_route(tunnel->net, dst, fl, NULL, 0);
215 	if (IS_ERR(dst)) {
216 		dev->stats.tx_carrier_errors++;
217 		goto tx_error_icmp;
218 	}
219 
220 	if (dst->flags & DST_XFRM_QUEUE)
221 		goto queued;
222 
223 	if (!vti_state_check(dst->xfrm, parms->iph.daddr, parms->iph.saddr)) {
224 		dev->stats.tx_carrier_errors++;
225 		dst_release(dst);
226 		goto tx_error_icmp;
227 	}
228 
229 	tdev = dst->dev;
230 
231 	if (tdev == dev) {
232 		dst_release(dst);
233 		dev->stats.collisions++;
234 		goto tx_error;
235 	}
236 
237 	mtu = dst_mtu(dst);
238 	if (skb->len > mtu) {
239 		skb_dst_update_pmtu_no_confirm(skb, mtu);
240 		if (skb->protocol == htons(ETH_P_IP)) {
241 			icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
242 				  htonl(mtu));
243 		} else {
244 			if (mtu < IPV6_MIN_MTU)
245 				mtu = IPV6_MIN_MTU;
246 
247 			icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
248 		}
249 
250 		dst_release(dst);
251 		goto tx_error;
252 	}
253 
254 queued:
255 	skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(dev)));
256 	skb_dst_set(skb, dst);
257 	skb->dev = skb_dst(skb)->dev;
258 
259 	err = dst_output(tunnel->net, skb->sk, skb);
260 	if (net_xmit_eval(err) == 0)
261 		err = pkt_len;
262 	iptunnel_xmit_stats(dev, err);
263 	return NETDEV_TX_OK;
264 
265 tx_error_icmp:
266 	dst_link_failure(skb);
267 tx_error:
268 	dev->stats.tx_errors++;
269 	kfree_skb(skb);
270 	return NETDEV_TX_OK;
271 }
272 
273 /* This function assumes it is being called from dev_queue_xmit()
274  * and that skb is filled properly by that function.
275  */
276 static netdev_tx_t vti_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
277 {
278 	struct ip_tunnel *tunnel = netdev_priv(dev);
279 	struct flowi fl;
280 
281 	if (!pskb_inet_may_pull(skb))
282 		goto tx_err;
283 
284 	memset(&fl, 0, sizeof(fl));
285 
286 	switch (skb->protocol) {
287 	case htons(ETH_P_IP):
288 		xfrm_decode_session(skb, &fl, AF_INET);
289 		memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
290 		break;
291 	case htons(ETH_P_IPV6):
292 		xfrm_decode_session(skb, &fl, AF_INET6);
293 		memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
294 		break;
295 	default:
296 		goto tx_err;
297 	}
298 
299 	/* override mark with tunnel output key */
300 	fl.flowi_mark = be32_to_cpu(tunnel->parms.o_key);
301 
302 	return vti_xmit(skb, dev, &fl);
303 
304 tx_err:
305 	dev->stats.tx_errors++;
306 	kfree_skb(skb);
307 	return NETDEV_TX_OK;
308 }
309 
310 static int vti4_err(struct sk_buff *skb, u32 info)
311 {
312 	__be32 spi;
313 	__u32 mark;
314 	struct xfrm_state *x;
315 	struct ip_tunnel *tunnel;
316 	struct ip_esp_hdr *esph;
317 	struct ip_auth_hdr *ah ;
318 	struct ip_comp_hdr *ipch;
319 	struct net *net = dev_net(skb->dev);
320 	const struct iphdr *iph = (const struct iphdr *)skb->data;
321 	int protocol = iph->protocol;
322 	struct ip_tunnel_net *itn = net_generic(net, vti_net_id);
323 
324 	tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY,
325 				  iph->daddr, iph->saddr, 0);
326 	if (!tunnel)
327 		return -1;
328 
329 	mark = be32_to_cpu(tunnel->parms.o_key);
330 
331 	switch (protocol) {
332 	case IPPROTO_ESP:
333 		esph = (struct ip_esp_hdr *)(skb->data+(iph->ihl<<2));
334 		spi = esph->spi;
335 		break;
336 	case IPPROTO_AH:
337 		ah = (struct ip_auth_hdr *)(skb->data+(iph->ihl<<2));
338 		spi = ah->spi;
339 		break;
340 	case IPPROTO_COMP:
341 		ipch = (struct ip_comp_hdr *)(skb->data+(iph->ihl<<2));
342 		spi = htonl(ntohs(ipch->cpi));
343 		break;
344 	default:
345 		return 0;
346 	}
347 
348 	switch (icmp_hdr(skb)->type) {
349 	case ICMP_DEST_UNREACH:
350 		if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
351 			return 0;
352 	case ICMP_REDIRECT:
353 		break;
354 	default:
355 		return 0;
356 	}
357 
358 	x = xfrm_state_lookup(net, mark, (const xfrm_address_t *)&iph->daddr,
359 			      spi, protocol, AF_INET);
360 	if (!x)
361 		return 0;
362 
363 	if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH)
364 		ipv4_update_pmtu(skb, net, info, 0, protocol);
365 	else
366 		ipv4_redirect(skb, net, 0, protocol);
367 	xfrm_state_put(x);
368 
369 	return 0;
370 }
371 
372 static int
373 vti_tunnel_ctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd)
374 {
375 	int err = 0;
376 
377 	if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) {
378 		if (p->iph.version != 4 || p->iph.protocol != IPPROTO_IPIP ||
379 		    p->iph.ihl != 5)
380 			return -EINVAL;
381 	}
382 
383 	if (!(p->i_flags & GRE_KEY))
384 		p->i_key = 0;
385 	if (!(p->o_flags & GRE_KEY))
386 		p->o_key = 0;
387 
388 	p->i_flags = VTI_ISVTI;
389 
390 	err = ip_tunnel_ctl(dev, p, cmd);
391 	if (err)
392 		return err;
393 
394 	if (cmd != SIOCDELTUNNEL) {
395 		p->i_flags |= GRE_KEY;
396 		p->o_flags |= GRE_KEY;
397 	}
398 	return 0;
399 }
400 
401 static const struct net_device_ops vti_netdev_ops = {
402 	.ndo_init	= vti_tunnel_init,
403 	.ndo_uninit	= ip_tunnel_uninit,
404 	.ndo_start_xmit	= vti_tunnel_xmit,
405 	.ndo_do_ioctl	= ip_tunnel_ioctl,
406 	.ndo_change_mtu	= ip_tunnel_change_mtu,
407 	.ndo_get_stats64 = ip_tunnel_get_stats64,
408 	.ndo_get_iflink = ip_tunnel_get_iflink,
409 	.ndo_tunnel_ctl	= vti_tunnel_ctl,
410 };
411 
412 static void vti_tunnel_setup(struct net_device *dev)
413 {
414 	dev->netdev_ops		= &vti_netdev_ops;
415 	dev->header_ops		= &ip_tunnel_header_ops;
416 	dev->type		= ARPHRD_TUNNEL;
417 	ip_tunnel_setup(dev, vti_net_id);
418 }
419 
420 static int vti_tunnel_init(struct net_device *dev)
421 {
422 	struct ip_tunnel *tunnel = netdev_priv(dev);
423 	struct iphdr *iph = &tunnel->parms.iph;
424 
425 	memcpy(dev->dev_addr, &iph->saddr, 4);
426 	memcpy(dev->broadcast, &iph->daddr, 4);
427 
428 	dev->flags		= IFF_NOARP;
429 	dev->addr_len		= 4;
430 	dev->features		|= NETIF_F_LLTX;
431 	netif_keep_dst(dev);
432 
433 	return ip_tunnel_init(dev);
434 }
435 
436 static void __net_init vti_fb_tunnel_init(struct net_device *dev)
437 {
438 	struct ip_tunnel *tunnel = netdev_priv(dev);
439 	struct iphdr *iph = &tunnel->parms.iph;
440 
441 	iph->version		= 4;
442 	iph->protocol		= IPPROTO_IPIP;
443 	iph->ihl		= 5;
444 }
445 
446 static struct xfrm4_protocol vti_esp4_protocol __read_mostly = {
447 	.handler	=	vti_rcv_proto,
448 	.input_handler	=	vti_input_proto,
449 	.cb_handler	=	vti_rcv_cb,
450 	.err_handler	=	vti4_err,
451 	.priority	=	100,
452 };
453 
454 static struct xfrm4_protocol vti_ah4_protocol __read_mostly = {
455 	.handler	=	vti_rcv_proto,
456 	.input_handler	=	vti_input_proto,
457 	.cb_handler	=	vti_rcv_cb,
458 	.err_handler	=	vti4_err,
459 	.priority	=	100,
460 };
461 
462 static struct xfrm4_protocol vti_ipcomp4_protocol __read_mostly = {
463 	.handler	=	vti_rcv_proto,
464 	.input_handler	=	vti_input_proto,
465 	.cb_handler	=	vti_rcv_cb,
466 	.err_handler	=	vti4_err,
467 	.priority	=	100,
468 };
469 
470 #if IS_ENABLED(CONFIG_INET_XFRM_TUNNEL)
471 static int vti_rcv_tunnel(struct sk_buff *skb)
472 {
473 	XFRM_SPI_SKB_CB(skb)->family = AF_INET;
474 	XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct iphdr, daddr);
475 
476 	return vti_input(skb, IPPROTO_IPIP, ip_hdr(skb)->saddr, 0, false);
477 }
478 
479 static struct xfrm_tunnel vti_ipip_handler __read_mostly = {
480 	.handler	=	vti_rcv_tunnel,
481 	.cb_handler	=	vti_rcv_cb,
482 	.err_handler	=	vti4_err,
483 	.priority	=	0,
484 };
485 
486 #if IS_ENABLED(CONFIG_IPV6)
487 static struct xfrm_tunnel vti_ipip6_handler __read_mostly = {
488 	.handler	=	vti_rcv_tunnel,
489 	.cb_handler	=	vti_rcv_cb,
490 	.err_handler	=	vti4_err,
491 	.priority	=	0,
492 };
493 #endif
494 #endif
495 
496 static int __net_init vti_init_net(struct net *net)
497 {
498 	int err;
499 	struct ip_tunnel_net *itn;
500 
501 	err = ip_tunnel_init_net(net, vti_net_id, &vti_link_ops, "ip_vti0");
502 	if (err)
503 		return err;
504 	itn = net_generic(net, vti_net_id);
505 	if (itn->fb_tunnel_dev)
506 		vti_fb_tunnel_init(itn->fb_tunnel_dev);
507 	return 0;
508 }
509 
510 static void __net_exit vti_exit_batch_net(struct list_head *list_net)
511 {
512 	ip_tunnel_delete_nets(list_net, vti_net_id, &vti_link_ops);
513 }
514 
515 static struct pernet_operations vti_net_ops = {
516 	.init = vti_init_net,
517 	.exit_batch = vti_exit_batch_net,
518 	.id   = &vti_net_id,
519 	.size = sizeof(struct ip_tunnel_net),
520 };
521 
522 static int vti_tunnel_validate(struct nlattr *tb[], struct nlattr *data[],
523 			       struct netlink_ext_ack *extack)
524 {
525 	return 0;
526 }
527 
528 static void vti_netlink_parms(struct nlattr *data[],
529 			      struct ip_tunnel_parm *parms,
530 			      __u32 *fwmark)
531 {
532 	memset(parms, 0, sizeof(*parms));
533 
534 	parms->iph.protocol = IPPROTO_IPIP;
535 
536 	if (!data)
537 		return;
538 
539 	parms->i_flags = VTI_ISVTI;
540 
541 	if (data[IFLA_VTI_LINK])
542 		parms->link = nla_get_u32(data[IFLA_VTI_LINK]);
543 
544 	if (data[IFLA_VTI_IKEY])
545 		parms->i_key = nla_get_be32(data[IFLA_VTI_IKEY]);
546 
547 	if (data[IFLA_VTI_OKEY])
548 		parms->o_key = nla_get_be32(data[IFLA_VTI_OKEY]);
549 
550 	if (data[IFLA_VTI_LOCAL])
551 		parms->iph.saddr = nla_get_in_addr(data[IFLA_VTI_LOCAL]);
552 
553 	if (data[IFLA_VTI_REMOTE])
554 		parms->iph.daddr = nla_get_in_addr(data[IFLA_VTI_REMOTE]);
555 
556 	if (data[IFLA_VTI_FWMARK])
557 		*fwmark = nla_get_u32(data[IFLA_VTI_FWMARK]);
558 }
559 
560 static int vti_newlink(struct net *src_net, struct net_device *dev,
561 		       struct nlattr *tb[], struct nlattr *data[],
562 		       struct netlink_ext_ack *extack)
563 {
564 	struct ip_tunnel_parm parms;
565 	__u32 fwmark = 0;
566 
567 	vti_netlink_parms(data, &parms, &fwmark);
568 	return ip_tunnel_newlink(dev, tb, &parms, fwmark);
569 }
570 
571 static int vti_changelink(struct net_device *dev, struct nlattr *tb[],
572 			  struct nlattr *data[],
573 			  struct netlink_ext_ack *extack)
574 {
575 	struct ip_tunnel *t = netdev_priv(dev);
576 	__u32 fwmark = t->fwmark;
577 	struct ip_tunnel_parm p;
578 
579 	vti_netlink_parms(data, &p, &fwmark);
580 	return ip_tunnel_changelink(dev, tb, &p, fwmark);
581 }
582 
583 static size_t vti_get_size(const struct net_device *dev)
584 {
585 	return
586 		/* IFLA_VTI_LINK */
587 		nla_total_size(4) +
588 		/* IFLA_VTI_IKEY */
589 		nla_total_size(4) +
590 		/* IFLA_VTI_OKEY */
591 		nla_total_size(4) +
592 		/* IFLA_VTI_LOCAL */
593 		nla_total_size(4) +
594 		/* IFLA_VTI_REMOTE */
595 		nla_total_size(4) +
596 		/* IFLA_VTI_FWMARK */
597 		nla_total_size(4) +
598 		0;
599 }
600 
601 static int vti_fill_info(struct sk_buff *skb, const struct net_device *dev)
602 {
603 	struct ip_tunnel *t = netdev_priv(dev);
604 	struct ip_tunnel_parm *p = &t->parms;
605 
606 	if (nla_put_u32(skb, IFLA_VTI_LINK, p->link) ||
607 	    nla_put_be32(skb, IFLA_VTI_IKEY, p->i_key) ||
608 	    nla_put_be32(skb, IFLA_VTI_OKEY, p->o_key) ||
609 	    nla_put_in_addr(skb, IFLA_VTI_LOCAL, p->iph.saddr) ||
610 	    nla_put_in_addr(skb, IFLA_VTI_REMOTE, p->iph.daddr) ||
611 	    nla_put_u32(skb, IFLA_VTI_FWMARK, t->fwmark))
612 		return -EMSGSIZE;
613 
614 	return 0;
615 }
616 
617 static const struct nla_policy vti_policy[IFLA_VTI_MAX + 1] = {
618 	[IFLA_VTI_LINK]		= { .type = NLA_U32 },
619 	[IFLA_VTI_IKEY]		= { .type = NLA_U32 },
620 	[IFLA_VTI_OKEY]		= { .type = NLA_U32 },
621 	[IFLA_VTI_LOCAL]	= { .len = sizeof_field(struct iphdr, saddr) },
622 	[IFLA_VTI_REMOTE]	= { .len = sizeof_field(struct iphdr, daddr) },
623 	[IFLA_VTI_FWMARK]	= { .type = NLA_U32 },
624 };
625 
626 static struct rtnl_link_ops vti_link_ops __read_mostly = {
627 	.kind		= "vti",
628 	.maxtype	= IFLA_VTI_MAX,
629 	.policy		= vti_policy,
630 	.priv_size	= sizeof(struct ip_tunnel),
631 	.setup		= vti_tunnel_setup,
632 	.validate	= vti_tunnel_validate,
633 	.newlink	= vti_newlink,
634 	.changelink	= vti_changelink,
635 	.dellink        = ip_tunnel_dellink,
636 	.get_size	= vti_get_size,
637 	.fill_info	= vti_fill_info,
638 	.get_link_net	= ip_tunnel_get_link_net,
639 };
640 
641 static int __init vti_init(void)
642 {
643 	const char *msg;
644 	int err;
645 
646 	pr_info("IPv4 over IPsec tunneling driver\n");
647 
648 	msg = "tunnel device";
649 	err = register_pernet_device(&vti_net_ops);
650 	if (err < 0)
651 		goto pernet_dev_failed;
652 
653 	msg = "tunnel protocols";
654 	err = xfrm4_protocol_register(&vti_esp4_protocol, IPPROTO_ESP);
655 	if (err < 0)
656 		goto xfrm_proto_esp_failed;
657 	err = xfrm4_protocol_register(&vti_ah4_protocol, IPPROTO_AH);
658 	if (err < 0)
659 		goto xfrm_proto_ah_failed;
660 	err = xfrm4_protocol_register(&vti_ipcomp4_protocol, IPPROTO_COMP);
661 	if (err < 0)
662 		goto xfrm_proto_comp_failed;
663 
664 #if IS_ENABLED(CONFIG_INET_XFRM_TUNNEL)
665 	msg = "ipip tunnel";
666 	err = xfrm4_tunnel_register(&vti_ipip_handler, AF_INET);
667 	if (err < 0)
668 		goto xfrm_tunnel_ipip_failed;
669 #if IS_ENABLED(CONFIG_IPV6)
670 	err = xfrm4_tunnel_register(&vti_ipip6_handler, AF_INET6);
671 	if (err < 0)
672 		goto xfrm_tunnel_ipip6_failed;
673 #endif
674 #endif
675 
676 	msg = "netlink interface";
677 	err = rtnl_link_register(&vti_link_ops);
678 	if (err < 0)
679 		goto rtnl_link_failed;
680 
681 	return err;
682 
683 rtnl_link_failed:
684 #if IS_ENABLED(CONFIG_INET_XFRM_TUNNEL)
685 #if IS_ENABLED(CONFIG_IPV6)
686 	xfrm4_tunnel_deregister(&vti_ipip6_handler, AF_INET6);
687 xfrm_tunnel_ipip6_failed:
688 #endif
689 	xfrm4_tunnel_deregister(&vti_ipip_handler, AF_INET);
690 xfrm_tunnel_ipip_failed:
691 #endif
692 	xfrm4_protocol_deregister(&vti_ipcomp4_protocol, IPPROTO_COMP);
693 xfrm_proto_comp_failed:
694 	xfrm4_protocol_deregister(&vti_ah4_protocol, IPPROTO_AH);
695 xfrm_proto_ah_failed:
696 	xfrm4_protocol_deregister(&vti_esp4_protocol, IPPROTO_ESP);
697 xfrm_proto_esp_failed:
698 	unregister_pernet_device(&vti_net_ops);
699 pernet_dev_failed:
700 	pr_err("vti init: failed to register %s\n", msg);
701 	return err;
702 }
703 
704 static void __exit vti_fini(void)
705 {
706 	rtnl_link_unregister(&vti_link_ops);
707 #if IS_ENABLED(CONFIG_INET_XFRM_TUNNEL)
708 #if IS_ENABLED(CONFIG_IPV6)
709 	xfrm4_tunnel_deregister(&vti_ipip6_handler, AF_INET6);
710 #endif
711 	xfrm4_tunnel_deregister(&vti_ipip_handler, AF_INET);
712 #endif
713 	xfrm4_protocol_deregister(&vti_ipcomp4_protocol, IPPROTO_COMP);
714 	xfrm4_protocol_deregister(&vti_ah4_protocol, IPPROTO_AH);
715 	xfrm4_protocol_deregister(&vti_esp4_protocol, IPPROTO_ESP);
716 	unregister_pernet_device(&vti_net_ops);
717 }
718 
719 module_init(vti_init);
720 module_exit(vti_fini);
721 MODULE_LICENSE("GPL");
722 MODULE_ALIAS_RTNL_LINK("vti");
723 MODULE_ALIAS_NETDEV("ip_vti0");
724