xref: /linux/net/ipv4/ipip.c (revision c36461825469a9ceee2346a2e89286c522525da7)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *	Linux NET3:	IP/IP protocol decoder.
4  *
5  *	Authors:
6  *		Sam Lantinga (slouken@cs.ucdavis.edu)  02/01/95
7  *
8  *	Fixes:
9  *		Alan Cox	:	Merged and made usable non modular (its so tiny its silly as
10  *					a module taking up 2 pages).
11  *		Alan Cox	: 	Fixed bug with 1.3.18 and IPIP not working (now needs to set skb->h.iph)
12  *					to keep ip_forward happy.
13  *		Alan Cox	:	More fixes for 1.3.21, and firewall fix. Maybe this will work soon 8).
14  *		Kai Schulte	:	Fixed #defines for IP_FIREWALL->FIREWALL
15  *              David Woodhouse :       Perform some basic ICMP handling.
16  *                                      IPIP Routing without decapsulation.
17  *              Carlos Picoto   :       GRE over IP support
18  *		Alexey Kuznetsov:	Reworked. Really, now it is truncated version of ipv4/ip_gre.c.
19  *					I do not want to merge them together.
20  */
21 
22 /* tunnel.c: an IP tunnel driver
23 
24 	The purpose of this driver is to provide an IP tunnel through
25 	which you can tunnel network traffic transparently across subnets.
26 
27 	This was written by looking at Nick Holloway's dummy driver
28 	Thanks for the great code!
29 
30 		-Sam Lantinga	(slouken@cs.ucdavis.edu)  02/01/95
31 
32 	Minor tweaks:
33 		Cleaned up the code a little and added some pre-1.3.0 tweaks.
34 		dev->hard_header/hard_header_len changed to use no headers.
35 		Comments/bracketing tweaked.
36 		Made the tunnels use dev->name not tunnel: when error reporting.
37 		Added tx_dropped stat
38 
39 		-Alan Cox	(alan@lxorguk.ukuu.org.uk) 21 March 95
40 
41 	Reworked:
42 		Changed to tunnel to destination gateway in addition to the
43 			tunnel's pointopoint address
44 		Almost completely rewritten
45 		Note:  There is currently no firewall or ICMP handling done.
46 
47 		-Sam Lantinga	(slouken@cs.ucdavis.edu) 02/13/96
48 
49 */
50 
51 /* Things I wish I had known when writing the tunnel driver:
52 
53 	When the tunnel_xmit() function is called, the skb contains the
54 	packet to be sent (plus a great deal of extra info), and dev
55 	contains the tunnel device that _we_ are.
56 
57 	When we are passed a packet, we are expected to fill in the
58 	source address with our source IP address.
59 
60 	What is the proper way to allocate, copy and free a buffer?
61 	After you allocate it, it is a "0 length" chunk of memory
62 	starting at zero.  If you want to add headers to the buffer
63 	later, you'll have to call "skb_reserve(skb, amount)" with
64 	the amount of memory you want reserved.  Then, you call
65 	"skb_put(skb, amount)" with the amount of space you want in
66 	the buffer.  skb_put() returns a pointer to the top (#0) of
67 	that buffer.  skb->len is set to the amount of space you have
68 	"allocated" with skb_put().  You can then write up to skb->len
69 	bytes to that buffer.  If you need more, you can call skb_put()
70 	again with the additional amount of space you need.  You can
71 	find out how much more space you can allocate by calling
72 	"skb_tailroom(skb)".
73 	Now, to add header space, call "skb_push(skb, header_len)".
74 	This creates space at the beginning of the buffer and returns
75 	a pointer to this new space.  If later you need to strip a
76 	header from a buffer, call "skb_pull(skb, header_len)".
77 	skb_headroom() will return how much space is left at the top
78 	of the buffer (before the main data).  Remember, this headroom
79 	space must be reserved before the skb_put() function is called.
80 	*/
81 
82 /*
83    This version of net/ipv4/ipip.c is cloned of net/ipv4/ip_gre.c
84 
85    For comments look at net/ipv4/ip_gre.c --ANK
86  */
87 
88 
89 #include <linux/capability.h>
90 #include <linux/module.h>
91 #include <linux/types.h>
92 #include <linux/kernel.h>
93 #include <linux/slab.h>
94 #include <linux/uaccess.h>
95 #include <linux/skbuff.h>
96 #include <linux/netdevice.h>
97 #include <linux/in.h>
98 #include <linux/tcp.h>
99 #include <linux/udp.h>
100 #include <linux/if_arp.h>
101 #include <linux/init.h>
102 #include <linux/netfilter_ipv4.h>
103 #include <linux/if_ether.h>
104 
105 #include <net/sock.h>
106 #include <net/ip.h>
107 #include <net/icmp.h>
108 #include <net/ip_tunnels.h>
109 #include <net/inet_ecn.h>
110 #include <net/xfrm.h>
111 #include <net/net_namespace.h>
112 #include <net/netns/generic.h>
113 #include <net/dst_metadata.h>
114 
115 static bool log_ecn_error = true;
116 module_param(log_ecn_error, bool, 0644);
117 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
118 
119 static unsigned int ipip_net_id __read_mostly;
120 
121 static int ipip_tunnel_init(struct net_device *dev);
122 static struct rtnl_link_ops ipip_link_ops __read_mostly;
123 
124 static int ipip_err(struct sk_buff *skb, u32 info)
125 {
126 	/* All the routers (except for Linux) return only
127 	 * 8 bytes of packet payload. It means, that precise relaying of
128 	 * ICMP in the real Internet is absolutely infeasible.
129 	 */
130 	struct net *net = dev_net(skb->dev);
131 	struct ip_tunnel_net *itn = net_generic(net, ipip_net_id);
132 	const struct iphdr *iph = (const struct iphdr *)skb->data;
133 	IP_TUNNEL_DECLARE_FLAGS(flags) = { };
134 	const int type = icmp_hdr(skb)->type;
135 	const int code = icmp_hdr(skb)->code;
136 	struct ip_tunnel *t;
137 	int err = 0;
138 
139 	__set_bit(IP_TUNNEL_NO_KEY_BIT, flags);
140 
141 	t = ip_tunnel_lookup(itn, skb->dev->ifindex, flags, iph->daddr,
142 			     iph->saddr, 0);
143 	if (!t) {
144 		err = -ENOENT;
145 		goto out;
146 	}
147 
148 	switch (type) {
149 	case ICMP_DEST_UNREACH:
150 		switch (code) {
151 		case ICMP_SR_FAILED:
152 			/* Impossible event. */
153 			goto out;
154 		default:
155 			/* All others are translated to HOST_UNREACH.
156 			 * rfc2003 contains "deep thoughts" about NET_UNREACH,
157 			 * I believe they are just ether pollution. --ANK
158 			 */
159 			break;
160 		}
161 		break;
162 
163 	case ICMP_TIME_EXCEEDED:
164 		if (code != ICMP_EXC_TTL)
165 			goto out;
166 		break;
167 
168 	case ICMP_REDIRECT:
169 		break;
170 
171 	default:
172 		goto out;
173 	}
174 
175 	if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
176 		ipv4_update_pmtu(skb, net, info, t->parms.link, iph->protocol);
177 		goto out;
178 	}
179 
180 	if (type == ICMP_REDIRECT) {
181 		ipv4_redirect(skb, net, t->parms.link, iph->protocol);
182 		goto out;
183 	}
184 
185 	if (t->parms.iph.daddr == 0) {
186 		err = -ENOENT;
187 		goto out;
188 	}
189 
190 	if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
191 		goto out;
192 
193 	if (time_before(jiffies, READ_ONCE(t->err_time) + IPTUNNEL_ERR_TIMEO))
194 		WRITE_ONCE(t->err_count, READ_ONCE(t->err_count) + 1);
195 	else
196 		WRITE_ONCE(t->err_count, 1);
197 	WRITE_ONCE(t->err_time, jiffies);
198 
199 out:
200 	return err;
201 }
202 
203 static const struct tnl_ptk_info ipip_tpi = {
204 	/* no tunnel info required for ipip. */
205 	.proto = htons(ETH_P_IP),
206 };
207 
208 #if IS_ENABLED(CONFIG_MPLS)
209 static const struct tnl_ptk_info mplsip_tpi = {
210 	/* no tunnel info required for mplsip. */
211 	.proto = htons(ETH_P_MPLS_UC),
212 };
213 #endif
214 
215 static int ipip_tunnel_rcv(struct sk_buff *skb, u8 ipproto)
216 {
217 	struct net *net = dev_net(skb->dev);
218 	struct ip_tunnel_net *itn = net_generic(net, ipip_net_id);
219 	IP_TUNNEL_DECLARE_FLAGS(flags) = { };
220 	struct metadata_dst *tun_dst = NULL;
221 	struct ip_tunnel *tunnel;
222 	const struct iphdr *iph;
223 
224 	__set_bit(IP_TUNNEL_NO_KEY_BIT, flags);
225 
226 	iph = ip_hdr(skb);
227 	tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, flags, iph->saddr,
228 				  iph->daddr, 0);
229 	if (tunnel) {
230 		const struct tnl_ptk_info *tpi;
231 
232 		if (tunnel->parms.iph.protocol != ipproto &&
233 		    tunnel->parms.iph.protocol != 0)
234 			goto drop;
235 
236 		if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
237 			goto drop;
238 #if IS_ENABLED(CONFIG_MPLS)
239 		if (ipproto == IPPROTO_MPLS)
240 			tpi = &mplsip_tpi;
241 		else
242 #endif
243 			tpi = &ipip_tpi;
244 		if (iptunnel_pull_header(skb, 0, tpi->proto, false))
245 			goto drop;
246 		if (tunnel->collect_md) {
247 			ip_tunnel_flags_zero(flags);
248 
249 			tun_dst = ip_tun_rx_dst(skb, flags, 0, 0);
250 			if (!tun_dst)
251 				return 0;
252 			ip_tunnel_md_udp_encap(skb, &tun_dst->u.tun_info);
253 		}
254 		skb_reset_mac_header(skb);
255 
256 		return ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error);
257 	}
258 
259 	return -1;
260 
261 drop:
262 	kfree_skb(skb);
263 	return 0;
264 }
265 
266 static int ipip_rcv(struct sk_buff *skb)
267 {
268 	return ipip_tunnel_rcv(skb, IPPROTO_IPIP);
269 }
270 
271 #if IS_ENABLED(CONFIG_MPLS)
272 static int mplsip_rcv(struct sk_buff *skb)
273 {
274 	return ipip_tunnel_rcv(skb, IPPROTO_MPLS);
275 }
276 #endif
277 
278 /*
279  *	This function assumes it is being called from dev_queue_xmit()
280  *	and that skb is filled properly by that function.
281  */
282 static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb,
283 				    struct net_device *dev)
284 {
285 	struct ip_tunnel *tunnel = netdev_priv(dev);
286 	const struct iphdr  *tiph = &tunnel->parms.iph;
287 	u8 ipproto;
288 
289 	if (!pskb_inet_may_pull(skb))
290 		goto tx_error;
291 
292 	switch (skb->protocol) {
293 	case htons(ETH_P_IP):
294 		ipproto = IPPROTO_IPIP;
295 		break;
296 #if IS_ENABLED(CONFIG_MPLS)
297 	case htons(ETH_P_MPLS_UC):
298 		ipproto = IPPROTO_MPLS;
299 		break;
300 #endif
301 	default:
302 		goto tx_error;
303 	}
304 
305 	if (tiph->protocol != ipproto && tiph->protocol != 0)
306 		goto tx_error;
307 
308 	if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP4))
309 		goto tx_error;
310 
311 	skb_set_inner_ipproto(skb, ipproto);
312 
313 	if (tunnel->collect_md)
314 		ip_md_tunnel_xmit(skb, dev, ipproto, 0);
315 	else
316 		ip_tunnel_xmit(skb, dev, tiph, ipproto);
317 	return NETDEV_TX_OK;
318 
319 tx_error:
320 	kfree_skb(skb);
321 
322 	DEV_STATS_INC(dev, tx_errors);
323 	return NETDEV_TX_OK;
324 }
325 
326 static bool ipip_tunnel_ioctl_verify_protocol(u8 ipproto)
327 {
328 	switch (ipproto) {
329 	case 0:
330 	case IPPROTO_IPIP:
331 #if IS_ENABLED(CONFIG_MPLS)
332 	case IPPROTO_MPLS:
333 #endif
334 		return true;
335 	}
336 
337 	return false;
338 }
339 
340 static int
341 ipip_tunnel_ctl(struct net_device *dev, struct ip_tunnel_parm_kern *p, int cmd)
342 {
343 	if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) {
344 		if (p->iph.version != 4 ||
345 		    !ipip_tunnel_ioctl_verify_protocol(p->iph.protocol) ||
346 		    p->iph.ihl != 5 || (p->iph.frag_off & htons(~IP_DF)))
347 			return -EINVAL;
348 	}
349 
350 	p->i_key = p->o_key = 0;
351 	ip_tunnel_flags_zero(p->i_flags);
352 	ip_tunnel_flags_zero(p->o_flags);
353 	return ip_tunnel_ctl(dev, p, cmd);
354 }
355 
356 static int ipip_fill_forward_path(struct net_device_path_ctx *ctx,
357 				  struct net_device_path *path)
358 {
359 	struct ip_tunnel *tunnel = netdev_priv(ctx->dev);
360 	const struct iphdr *tiph = &tunnel->parms.iph;
361 	struct rtable *rt;
362 
363 	if (ctx->ether_type != cpu_to_be16(ETH_P_IP))
364 		return -EOPNOTSUPP;
365 
366 	if (tunnel->collect_md)
367 		return -EOPNOTSUPP;
368 
369 	if (tunnel->parms.iph.tos & 0x1)
370 		return -EOPNOTSUPP;
371 
372 	rt = ip_route_output(dev_net(ctx->dev), tiph->daddr, tiph->saddr,
373 			     inet_dsfield_to_dscp(tiph->tos),
374 			     tunnel->parms.link, RT_SCOPE_UNIVERSE);
375 	if (IS_ERR(rt))
376 		return PTR_ERR(rt);
377 
378 	path->type = DEV_PATH_TUN;
379 	path->tun.src_v4.s_addr = tiph->saddr;
380 	path->tun.dst_v4.s_addr = tiph->daddr;
381 	path->tun.inner_proto = IPPROTO_IPIP;
382 	path->tun.dst = &rt->dst;
383 	path->dev = ctx->dev;
384 
385 	ctx->dev = rt->dst.dev;
386 
387 	return 0;
388 }
389 
390 static const struct net_device_ops ipip_netdev_ops = {
391 	.ndo_init       = ipip_tunnel_init,
392 	.ndo_uninit     = ip_tunnel_uninit,
393 	.ndo_start_xmit	= ipip_tunnel_xmit,
394 	.ndo_siocdevprivate = ip_tunnel_siocdevprivate,
395 	.ndo_change_mtu = ip_tunnel_change_mtu,
396 	.ndo_get_stats64 = dev_get_tstats64,
397 	.ndo_get_iflink = ip_tunnel_get_iflink,
398 	.ndo_tunnel_ctl	= ipip_tunnel_ctl,
399 	.ndo_fill_forward_path = ipip_fill_forward_path,
400 };
401 
402 #define IPIP_FEATURES (NETIF_F_SG |		\
403 		       NETIF_F_FRAGLIST |	\
404 		       NETIF_F_HIGHDMA |	\
405 		       NETIF_F_GSO_SOFTWARE |	\
406 		       NETIF_F_HW_CSUM)
407 
408 static void ipip_tunnel_setup(struct net_device *dev)
409 {
410 	dev->netdev_ops		= &ipip_netdev_ops;
411 	dev->header_ops		= &ip_tunnel_header_ops;
412 
413 	dev->type		= ARPHRD_TUNNEL;
414 	dev->flags		= IFF_NOARP;
415 	dev->addr_len		= 4;
416 	dev->lltx		= true;
417 	netif_keep_dst(dev);
418 
419 	dev->features		|= IPIP_FEATURES;
420 	dev->hw_features	|= IPIP_FEATURES;
421 	ip_tunnel_setup(dev, ipip_net_id);
422 }
423 
424 static int ipip_tunnel_init(struct net_device *dev)
425 {
426 	struct ip_tunnel *tunnel = netdev_priv(dev);
427 
428 	__dev_addr_set(dev, &tunnel->parms.iph.saddr, 4);
429 	memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
430 
431 	tunnel->tun_hlen = 0;
432 	tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen;
433 	return ip_tunnel_init(dev);
434 }
435 
436 static int ipip_tunnel_validate(struct nlattr *tb[], struct nlattr *data[],
437 				struct netlink_ext_ack *extack)
438 {
439 	u8 proto;
440 
441 	if (!data || !data[IFLA_IPTUN_PROTO])
442 		return 0;
443 
444 	proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
445 	if (proto != IPPROTO_IPIP && proto != IPPROTO_MPLS && proto != 0)
446 		return -EINVAL;
447 
448 	return 0;
449 }
450 
451 static void ipip_netlink_parms(struct nlattr *data[],
452 			       struct ip_tunnel_parm_kern *parms,
453 			       bool *collect_md, __u32 *fwmark)
454 {
455 	memset(parms, 0, sizeof(*parms));
456 
457 	parms->iph.version = 4;
458 	parms->iph.protocol = IPPROTO_IPIP;
459 	parms->iph.ihl = 5;
460 	*collect_md = false;
461 
462 	if (!data)
463 		return;
464 
465 	ip_tunnel_netlink_parms(data, parms);
466 
467 	if (data[IFLA_IPTUN_COLLECT_METADATA])
468 		*collect_md = true;
469 
470 	if (data[IFLA_IPTUN_FWMARK])
471 		*fwmark = nla_get_u32(data[IFLA_IPTUN_FWMARK]);
472 }
473 
474 static int ipip_newlink(struct net_device *dev,
475 			struct rtnl_newlink_params *params,
476 			struct netlink_ext_ack *extack)
477 {
478 	struct ip_tunnel *t = netdev_priv(dev);
479 	struct nlattr **data = params->data;
480 	struct nlattr **tb = params->tb;
481 	struct ip_tunnel_encap ipencap;
482 	struct ip_tunnel_parm_kern p;
483 	__u32 fwmark = 0;
484 
485 	if (ip_tunnel_netlink_encap_parms(data, &ipencap)) {
486 		int err = ip_tunnel_encap_setup(t, &ipencap);
487 
488 		if (err < 0)
489 			return err;
490 	}
491 
492 	ipip_netlink_parms(data, &p, &t->collect_md, &fwmark);
493 	return ip_tunnel_newlink(params->link_net ? : dev_net(dev), dev, tb, &p,
494 				 fwmark);
495 }
496 
497 static int ipip_changelink(struct net_device *dev, struct nlattr *tb[],
498 			   struct nlattr *data[],
499 			   struct netlink_ext_ack *extack)
500 {
501 	struct ip_tunnel *t = netdev_priv(dev);
502 	struct ip_tunnel_encap ipencap;
503 	struct ip_tunnel_parm_kern p;
504 	bool collect_md;
505 	__u32 fwmark = t->fwmark;
506 
507 	if (!rtnl_dev_link_net_capable(dev, t->net))
508 		return -EPERM;
509 
510 	if (ip_tunnel_netlink_encap_parms(data, &ipencap)) {
511 		int err = ip_tunnel_encap_setup(t, &ipencap);
512 
513 		if (err < 0)
514 			return err;
515 	}
516 
517 	ipip_netlink_parms(data, &p, &collect_md, &fwmark);
518 	if (collect_md)
519 		return -EINVAL;
520 
521 	if (((dev->flags & IFF_POINTOPOINT) && !p.iph.daddr) ||
522 	    (!(dev->flags & IFF_POINTOPOINT) && p.iph.daddr))
523 		return -EINVAL;
524 
525 	return ip_tunnel_changelink(dev, tb, &p, fwmark);
526 }
527 
528 static size_t ipip_get_size(const struct net_device *dev)
529 {
530 	return
531 		/* IFLA_IPTUN_LINK */
532 		nla_total_size(4) +
533 		/* IFLA_IPTUN_LOCAL */
534 		nla_total_size(4) +
535 		/* IFLA_IPTUN_REMOTE */
536 		nla_total_size(4) +
537 		/* IFLA_IPTUN_TTL */
538 		nla_total_size(1) +
539 		/* IFLA_IPTUN_TOS */
540 		nla_total_size(1) +
541 		/* IFLA_IPTUN_PROTO */
542 		nla_total_size(1) +
543 		/* IFLA_IPTUN_PMTUDISC */
544 		nla_total_size(1) +
545 		/* IFLA_IPTUN_ENCAP_TYPE */
546 		nla_total_size(2) +
547 		/* IFLA_IPTUN_ENCAP_FLAGS */
548 		nla_total_size(2) +
549 		/* IFLA_IPTUN_ENCAP_SPORT */
550 		nla_total_size(2) +
551 		/* IFLA_IPTUN_ENCAP_DPORT */
552 		nla_total_size(2) +
553 		/* IFLA_IPTUN_COLLECT_METADATA */
554 		nla_total_size(0) +
555 		/* IFLA_IPTUN_FWMARK */
556 		nla_total_size(4) +
557 		0;
558 }
559 
560 static int ipip_fill_info(struct sk_buff *skb, const struct net_device *dev)
561 {
562 	struct ip_tunnel *tunnel = netdev_priv(dev);
563 	struct ip_tunnel_parm_kern *parm = &tunnel->parms;
564 
565 	if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
566 	    nla_put_in_addr(skb, IFLA_IPTUN_LOCAL, parm->iph.saddr) ||
567 	    nla_put_in_addr(skb, IFLA_IPTUN_REMOTE, parm->iph.daddr) ||
568 	    nla_put_u8(skb, IFLA_IPTUN_TTL, parm->iph.ttl) ||
569 	    nla_put_u8(skb, IFLA_IPTUN_TOS, parm->iph.tos) ||
570 	    nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->iph.protocol) ||
571 	    nla_put_u8(skb, IFLA_IPTUN_PMTUDISC,
572 		       !!(parm->iph.frag_off & htons(IP_DF))) ||
573 	    nla_put_u32(skb, IFLA_IPTUN_FWMARK, tunnel->fwmark))
574 		goto nla_put_failure;
575 
576 	if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE,
577 			tunnel->encap.type) ||
578 	    nla_put_be16(skb, IFLA_IPTUN_ENCAP_SPORT,
579 			 tunnel->encap.sport) ||
580 	    nla_put_be16(skb, IFLA_IPTUN_ENCAP_DPORT,
581 			 tunnel->encap.dport) ||
582 	    nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS,
583 			tunnel->encap.flags))
584 		goto nla_put_failure;
585 
586 	if (tunnel->collect_md)
587 		if (nla_put_flag(skb, IFLA_IPTUN_COLLECT_METADATA))
588 			goto nla_put_failure;
589 	return 0;
590 
591 nla_put_failure:
592 	return -EMSGSIZE;
593 }
594 
595 static const struct nla_policy ipip_policy[IFLA_IPTUN_MAX + 1] = {
596 	[IFLA_IPTUN_LINK]		= { .type = NLA_U32 },
597 	[IFLA_IPTUN_LOCAL]		= { .type = NLA_U32 },
598 	[IFLA_IPTUN_REMOTE]		= { .type = NLA_U32 },
599 	[IFLA_IPTUN_TTL]		= { .type = NLA_U8 },
600 	[IFLA_IPTUN_TOS]		= { .type = NLA_U8 },
601 	[IFLA_IPTUN_PROTO]		= { .type = NLA_U8 },
602 	[IFLA_IPTUN_PMTUDISC]		= { .type = NLA_U8 },
603 	[IFLA_IPTUN_ENCAP_TYPE]		= { .type = NLA_U16 },
604 	[IFLA_IPTUN_ENCAP_FLAGS]	= { .type = NLA_U16 },
605 	[IFLA_IPTUN_ENCAP_SPORT]	= { .type = NLA_U16 },
606 	[IFLA_IPTUN_ENCAP_DPORT]	= { .type = NLA_U16 },
607 	[IFLA_IPTUN_COLLECT_METADATA]	= { .type = NLA_FLAG },
608 	[IFLA_IPTUN_FWMARK]		= { .type = NLA_U32 },
609 };
610 
611 static struct rtnl_link_ops ipip_link_ops __read_mostly = {
612 	.kind		= "ipip",
613 	.maxtype	= IFLA_IPTUN_MAX,
614 	.policy		= ipip_policy,
615 	.priv_size	= sizeof(struct ip_tunnel),
616 	.setup		= ipip_tunnel_setup,
617 	.validate	= ipip_tunnel_validate,
618 	.newlink	= ipip_newlink,
619 	.changelink	= ipip_changelink,
620 	.dellink	= ip_tunnel_dellink,
621 	.get_size	= ipip_get_size,
622 	.fill_info	= ipip_fill_info,
623 	.get_link_net	= ip_tunnel_get_link_net,
624 };
625 
626 static struct xfrm_tunnel ipip_handler __read_mostly = {
627 	.handler	=	ipip_rcv,
628 	.err_handler	=	ipip_err,
629 	.priority	=	1,
630 };
631 
632 #if IS_ENABLED(CONFIG_MPLS)
633 static struct xfrm_tunnel mplsip_handler __read_mostly = {
634 	.handler	=	mplsip_rcv,
635 	.err_handler	=	ipip_err,
636 	.priority	=	1,
637 };
638 #endif
639 
640 static int __net_init ipip_init_net(struct net *net)
641 {
642 	return ip_tunnel_init_net(net, ipip_net_id, &ipip_link_ops, "tunl0");
643 }
644 
645 static void __net_exit ipip_exit_rtnl(struct net *net,
646 				      struct list_head *dev_to_kill)
647 {
648 	ip_tunnel_delete_net(net, ipip_net_id, &ipip_link_ops, dev_to_kill);
649 }
650 
651 static struct pernet_operations ipip_net_ops = {
652 	.init = ipip_init_net,
653 	.exit_rtnl = ipip_exit_rtnl,
654 	.id   = &ipip_net_id,
655 	.size = sizeof(struct ip_tunnel_net),
656 };
657 
658 static int __init ipip_init(void)
659 {
660 	int err;
661 
662 	pr_info("ipip: IPv4 and MPLS over IPv4 tunneling driver\n");
663 
664 	err = register_pernet_device(&ipip_net_ops);
665 	if (err < 0)
666 		return err;
667 	err = xfrm4_tunnel_register(&ipip_handler, AF_INET);
668 	if (err < 0) {
669 		pr_info("%s: can't register tunnel\n", __func__);
670 		goto xfrm_tunnel_ipip_failed;
671 	}
672 #if IS_ENABLED(CONFIG_MPLS)
673 	err = xfrm4_tunnel_register(&mplsip_handler, AF_MPLS);
674 	if (err < 0) {
675 		pr_info("%s: can't register tunnel\n", __func__);
676 		goto xfrm_tunnel_mplsip_failed;
677 	}
678 #endif
679 	err = rtnl_link_register(&ipip_link_ops);
680 	if (err < 0)
681 		goto rtnl_link_failed;
682 
683 out:
684 	return err;
685 
686 rtnl_link_failed:
687 #if IS_ENABLED(CONFIG_MPLS)
688 	xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS);
689 xfrm_tunnel_mplsip_failed:
690 
691 #endif
692 	xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
693 xfrm_tunnel_ipip_failed:
694 	unregister_pernet_device(&ipip_net_ops);
695 	goto out;
696 }
697 
698 static void __exit ipip_fini(void)
699 {
700 	rtnl_link_unregister(&ipip_link_ops);
701 	if (xfrm4_tunnel_deregister(&ipip_handler, AF_INET))
702 		pr_info("%s: can't deregister tunnel\n", __func__);
703 #if IS_ENABLED(CONFIG_MPLS)
704 	if (xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS))
705 		pr_info("%s: can't deregister tunnel\n", __func__);
706 #endif
707 	unregister_pernet_device(&ipip_net_ops);
708 }
709 
710 module_init(ipip_init);
711 module_exit(ipip_fini);
712 MODULE_DESCRIPTION("IP/IP protocol decoder library");
713 MODULE_LICENSE("GPL");
714 MODULE_ALIAS_RTNL_LINK("ipip");
715 MODULE_ALIAS_NETDEV("tunl0");
716