xref: /linux/net/ipv4/ipip.c (revision b8d312aa075f33282565467662c4628dae0a2aff)
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 	const int type = icmp_hdr(skb)->type;
134 	const int code = icmp_hdr(skb)->code;
135 	struct ip_tunnel *t;
136 	int err = 0;
137 
138 	t = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY,
139 			     iph->daddr, iph->saddr, 0);
140 	if (!t) {
141 		err = -ENOENT;
142 		goto out;
143 	}
144 
145 	switch (type) {
146 	case ICMP_DEST_UNREACH:
147 		switch (code) {
148 		case ICMP_SR_FAILED:
149 			/* Impossible event. */
150 			goto out;
151 		default:
152 			/* All others are translated to HOST_UNREACH.
153 			 * rfc2003 contains "deep thoughts" about NET_UNREACH,
154 			 * I believe they are just ether pollution. --ANK
155 			 */
156 			break;
157 		}
158 		break;
159 
160 	case ICMP_TIME_EXCEEDED:
161 		if (code != ICMP_EXC_TTL)
162 			goto out;
163 		break;
164 
165 	case ICMP_REDIRECT:
166 		break;
167 
168 	default:
169 		goto out;
170 	}
171 
172 	if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
173 		ipv4_update_pmtu(skb, net, info, t->parms.link, iph->protocol);
174 		goto out;
175 	}
176 
177 	if (type == ICMP_REDIRECT) {
178 		ipv4_redirect(skb, net, t->parms.link, iph->protocol);
179 		goto out;
180 	}
181 
182 	if (t->parms.iph.daddr == 0) {
183 		err = -ENOENT;
184 		goto out;
185 	}
186 
187 	if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
188 		goto out;
189 
190 	if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
191 		t->err_count++;
192 	else
193 		t->err_count = 1;
194 	t->err_time = jiffies;
195 
196 out:
197 	return err;
198 }
199 
200 static const struct tnl_ptk_info ipip_tpi = {
201 	/* no tunnel info required for ipip. */
202 	.proto = htons(ETH_P_IP),
203 };
204 
205 #if IS_ENABLED(CONFIG_MPLS)
206 static const struct tnl_ptk_info mplsip_tpi = {
207 	/* no tunnel info required for mplsip. */
208 	.proto = htons(ETH_P_MPLS_UC),
209 };
210 #endif
211 
212 static int ipip_tunnel_rcv(struct sk_buff *skb, u8 ipproto)
213 {
214 	struct net *net = dev_net(skb->dev);
215 	struct ip_tunnel_net *itn = net_generic(net, ipip_net_id);
216 	struct metadata_dst *tun_dst = NULL;
217 	struct ip_tunnel *tunnel;
218 	const struct iphdr *iph;
219 
220 	iph = ip_hdr(skb);
221 	tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY,
222 			iph->saddr, iph->daddr, 0);
223 	if (tunnel) {
224 		const struct tnl_ptk_info *tpi;
225 
226 		if (tunnel->parms.iph.protocol != ipproto &&
227 		    tunnel->parms.iph.protocol != 0)
228 			goto drop;
229 
230 		if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
231 			goto drop;
232 #if IS_ENABLED(CONFIG_MPLS)
233 		if (ipproto == IPPROTO_MPLS)
234 			tpi = &mplsip_tpi;
235 		else
236 #endif
237 			tpi = &ipip_tpi;
238 		if (iptunnel_pull_header(skb, 0, tpi->proto, false))
239 			goto drop;
240 		if (tunnel->collect_md) {
241 			tun_dst = ip_tun_rx_dst(skb, 0, 0, 0);
242 			if (!tun_dst)
243 				return 0;
244 		}
245 		return ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error);
246 	}
247 
248 	return -1;
249 
250 drop:
251 	kfree_skb(skb);
252 	return 0;
253 }
254 
255 static int ipip_rcv(struct sk_buff *skb)
256 {
257 	return ipip_tunnel_rcv(skb, IPPROTO_IPIP);
258 }
259 
260 #if IS_ENABLED(CONFIG_MPLS)
261 static int mplsip_rcv(struct sk_buff *skb)
262 {
263 	return ipip_tunnel_rcv(skb, IPPROTO_MPLS);
264 }
265 #endif
266 
267 /*
268  *	This function assumes it is being called from dev_queue_xmit()
269  *	and that skb is filled properly by that function.
270  */
271 static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb,
272 				    struct net_device *dev)
273 {
274 	struct ip_tunnel *tunnel = netdev_priv(dev);
275 	const struct iphdr  *tiph = &tunnel->parms.iph;
276 	u8 ipproto;
277 
278 	switch (skb->protocol) {
279 	case htons(ETH_P_IP):
280 		ipproto = IPPROTO_IPIP;
281 		break;
282 #if IS_ENABLED(CONFIG_MPLS)
283 	case htons(ETH_P_MPLS_UC):
284 		ipproto = IPPROTO_MPLS;
285 		break;
286 #endif
287 	default:
288 		goto tx_error;
289 	}
290 
291 	if (tiph->protocol != ipproto && tiph->protocol != 0)
292 		goto tx_error;
293 
294 	if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP4))
295 		goto tx_error;
296 
297 	skb_set_inner_ipproto(skb, ipproto);
298 
299 	if (tunnel->collect_md)
300 		ip_md_tunnel_xmit(skb, dev, ipproto, 0);
301 	else
302 		ip_tunnel_xmit(skb, dev, tiph, ipproto);
303 	return NETDEV_TX_OK;
304 
305 tx_error:
306 	kfree_skb(skb);
307 
308 	dev->stats.tx_errors++;
309 	return NETDEV_TX_OK;
310 }
311 
312 static bool ipip_tunnel_ioctl_verify_protocol(u8 ipproto)
313 {
314 	switch (ipproto) {
315 	case 0:
316 	case IPPROTO_IPIP:
317 #if IS_ENABLED(CONFIG_MPLS)
318 	case IPPROTO_MPLS:
319 #endif
320 		return true;
321 	}
322 
323 	return false;
324 }
325 
326 static int
327 ipip_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
328 {
329 	int err = 0;
330 	struct ip_tunnel_parm p;
331 
332 	if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
333 		return -EFAULT;
334 
335 	if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) {
336 		if (p.iph.version != 4 ||
337 		    !ipip_tunnel_ioctl_verify_protocol(p.iph.protocol) ||
338 		    p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)))
339 			return -EINVAL;
340 	}
341 
342 	p.i_key = p.o_key = 0;
343 	p.i_flags = p.o_flags = 0;
344 	err = ip_tunnel_ioctl(dev, &p, cmd);
345 	if (err)
346 		return err;
347 
348 	if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
349 		return -EFAULT;
350 
351 	return 0;
352 }
353 
354 static const struct net_device_ops ipip_netdev_ops = {
355 	.ndo_init       = ipip_tunnel_init,
356 	.ndo_uninit     = ip_tunnel_uninit,
357 	.ndo_start_xmit	= ipip_tunnel_xmit,
358 	.ndo_do_ioctl	= ipip_tunnel_ioctl,
359 	.ndo_change_mtu = ip_tunnel_change_mtu,
360 	.ndo_get_stats64 = ip_tunnel_get_stats64,
361 	.ndo_get_iflink = ip_tunnel_get_iflink,
362 };
363 
364 #define IPIP_FEATURES (NETIF_F_SG |		\
365 		       NETIF_F_FRAGLIST |	\
366 		       NETIF_F_HIGHDMA |	\
367 		       NETIF_F_GSO_SOFTWARE |	\
368 		       NETIF_F_HW_CSUM)
369 
370 static void ipip_tunnel_setup(struct net_device *dev)
371 {
372 	dev->netdev_ops		= &ipip_netdev_ops;
373 
374 	dev->type		= ARPHRD_TUNNEL;
375 	dev->flags		= IFF_NOARP;
376 	dev->addr_len		= 4;
377 	dev->features		|= NETIF_F_LLTX;
378 	netif_keep_dst(dev);
379 
380 	dev->features		|= IPIP_FEATURES;
381 	dev->hw_features	|= IPIP_FEATURES;
382 	ip_tunnel_setup(dev, ipip_net_id);
383 }
384 
385 static int ipip_tunnel_init(struct net_device *dev)
386 {
387 	struct ip_tunnel *tunnel = netdev_priv(dev);
388 
389 	memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
390 	memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
391 
392 	tunnel->tun_hlen = 0;
393 	tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen;
394 	return ip_tunnel_init(dev);
395 }
396 
397 static int ipip_tunnel_validate(struct nlattr *tb[], struct nlattr *data[],
398 				struct netlink_ext_ack *extack)
399 {
400 	u8 proto;
401 
402 	if (!data || !data[IFLA_IPTUN_PROTO])
403 		return 0;
404 
405 	proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
406 	if (proto != IPPROTO_IPIP && proto != IPPROTO_MPLS && proto != 0)
407 		return -EINVAL;
408 
409 	return 0;
410 }
411 
412 static void ipip_netlink_parms(struct nlattr *data[],
413 			       struct ip_tunnel_parm *parms, bool *collect_md,
414 			       __u32 *fwmark)
415 {
416 	memset(parms, 0, sizeof(*parms));
417 
418 	parms->iph.version = 4;
419 	parms->iph.protocol = IPPROTO_IPIP;
420 	parms->iph.ihl = 5;
421 	*collect_md = false;
422 
423 	if (!data)
424 		return;
425 
426 	if (data[IFLA_IPTUN_LINK])
427 		parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
428 
429 	if (data[IFLA_IPTUN_LOCAL])
430 		parms->iph.saddr = nla_get_in_addr(data[IFLA_IPTUN_LOCAL]);
431 
432 	if (data[IFLA_IPTUN_REMOTE])
433 		parms->iph.daddr = nla_get_in_addr(data[IFLA_IPTUN_REMOTE]);
434 
435 	if (data[IFLA_IPTUN_TTL]) {
436 		parms->iph.ttl = nla_get_u8(data[IFLA_IPTUN_TTL]);
437 		if (parms->iph.ttl)
438 			parms->iph.frag_off = htons(IP_DF);
439 	}
440 
441 	if (data[IFLA_IPTUN_TOS])
442 		parms->iph.tos = nla_get_u8(data[IFLA_IPTUN_TOS]);
443 
444 	if (data[IFLA_IPTUN_PROTO])
445 		parms->iph.protocol = nla_get_u8(data[IFLA_IPTUN_PROTO]);
446 
447 	if (!data[IFLA_IPTUN_PMTUDISC] || nla_get_u8(data[IFLA_IPTUN_PMTUDISC]))
448 		parms->iph.frag_off = htons(IP_DF);
449 
450 	if (data[IFLA_IPTUN_COLLECT_METADATA])
451 		*collect_md = true;
452 
453 	if (data[IFLA_IPTUN_FWMARK])
454 		*fwmark = nla_get_u32(data[IFLA_IPTUN_FWMARK]);
455 }
456 
457 /* This function returns true when ENCAP attributes are present in the nl msg */
458 static bool ipip_netlink_encap_parms(struct nlattr *data[],
459 				     struct ip_tunnel_encap *ipencap)
460 {
461 	bool ret = false;
462 
463 	memset(ipencap, 0, sizeof(*ipencap));
464 
465 	if (!data)
466 		return ret;
467 
468 	if (data[IFLA_IPTUN_ENCAP_TYPE]) {
469 		ret = true;
470 		ipencap->type = nla_get_u16(data[IFLA_IPTUN_ENCAP_TYPE]);
471 	}
472 
473 	if (data[IFLA_IPTUN_ENCAP_FLAGS]) {
474 		ret = true;
475 		ipencap->flags = nla_get_u16(data[IFLA_IPTUN_ENCAP_FLAGS]);
476 	}
477 
478 	if (data[IFLA_IPTUN_ENCAP_SPORT]) {
479 		ret = true;
480 		ipencap->sport = nla_get_be16(data[IFLA_IPTUN_ENCAP_SPORT]);
481 	}
482 
483 	if (data[IFLA_IPTUN_ENCAP_DPORT]) {
484 		ret = true;
485 		ipencap->dport = nla_get_be16(data[IFLA_IPTUN_ENCAP_DPORT]);
486 	}
487 
488 	return ret;
489 }
490 
491 static int ipip_newlink(struct net *src_net, struct net_device *dev,
492 			struct nlattr *tb[], struct nlattr *data[],
493 			struct netlink_ext_ack *extack)
494 {
495 	struct ip_tunnel *t = netdev_priv(dev);
496 	struct ip_tunnel_parm p;
497 	struct ip_tunnel_encap ipencap;
498 	__u32 fwmark = 0;
499 
500 	if (ipip_netlink_encap_parms(data, &ipencap)) {
501 		int err = ip_tunnel_encap_setup(t, &ipencap);
502 
503 		if (err < 0)
504 			return err;
505 	}
506 
507 	ipip_netlink_parms(data, &p, &t->collect_md, &fwmark);
508 	return ip_tunnel_newlink(dev, tb, &p, fwmark);
509 }
510 
511 static int ipip_changelink(struct net_device *dev, struct nlattr *tb[],
512 			   struct nlattr *data[],
513 			   struct netlink_ext_ack *extack)
514 {
515 	struct ip_tunnel *t = netdev_priv(dev);
516 	struct ip_tunnel_parm p;
517 	struct ip_tunnel_encap ipencap;
518 	bool collect_md;
519 	__u32 fwmark = t->fwmark;
520 
521 	if (ipip_netlink_encap_parms(data, &ipencap)) {
522 		int err = ip_tunnel_encap_setup(t, &ipencap);
523 
524 		if (err < 0)
525 			return err;
526 	}
527 
528 	ipip_netlink_parms(data, &p, &collect_md, &fwmark);
529 	if (collect_md)
530 		return -EINVAL;
531 
532 	if (((dev->flags & IFF_POINTOPOINT) && !p.iph.daddr) ||
533 	    (!(dev->flags & IFF_POINTOPOINT) && p.iph.daddr))
534 		return -EINVAL;
535 
536 	return ip_tunnel_changelink(dev, tb, &p, fwmark);
537 }
538 
539 static size_t ipip_get_size(const struct net_device *dev)
540 {
541 	return
542 		/* IFLA_IPTUN_LINK */
543 		nla_total_size(4) +
544 		/* IFLA_IPTUN_LOCAL */
545 		nla_total_size(4) +
546 		/* IFLA_IPTUN_REMOTE */
547 		nla_total_size(4) +
548 		/* IFLA_IPTUN_TTL */
549 		nla_total_size(1) +
550 		/* IFLA_IPTUN_TOS */
551 		nla_total_size(1) +
552 		/* IFLA_IPTUN_PROTO */
553 		nla_total_size(1) +
554 		/* IFLA_IPTUN_PMTUDISC */
555 		nla_total_size(1) +
556 		/* IFLA_IPTUN_ENCAP_TYPE */
557 		nla_total_size(2) +
558 		/* IFLA_IPTUN_ENCAP_FLAGS */
559 		nla_total_size(2) +
560 		/* IFLA_IPTUN_ENCAP_SPORT */
561 		nla_total_size(2) +
562 		/* IFLA_IPTUN_ENCAP_DPORT */
563 		nla_total_size(2) +
564 		/* IFLA_IPTUN_COLLECT_METADATA */
565 		nla_total_size(0) +
566 		/* IFLA_IPTUN_FWMARK */
567 		nla_total_size(4) +
568 		0;
569 }
570 
571 static int ipip_fill_info(struct sk_buff *skb, const struct net_device *dev)
572 {
573 	struct ip_tunnel *tunnel = netdev_priv(dev);
574 	struct ip_tunnel_parm *parm = &tunnel->parms;
575 
576 	if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
577 	    nla_put_in_addr(skb, IFLA_IPTUN_LOCAL, parm->iph.saddr) ||
578 	    nla_put_in_addr(skb, IFLA_IPTUN_REMOTE, parm->iph.daddr) ||
579 	    nla_put_u8(skb, IFLA_IPTUN_TTL, parm->iph.ttl) ||
580 	    nla_put_u8(skb, IFLA_IPTUN_TOS, parm->iph.tos) ||
581 	    nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->iph.protocol) ||
582 	    nla_put_u8(skb, IFLA_IPTUN_PMTUDISC,
583 		       !!(parm->iph.frag_off & htons(IP_DF))) ||
584 	    nla_put_u32(skb, IFLA_IPTUN_FWMARK, tunnel->fwmark))
585 		goto nla_put_failure;
586 
587 	if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE,
588 			tunnel->encap.type) ||
589 	    nla_put_be16(skb, IFLA_IPTUN_ENCAP_SPORT,
590 			 tunnel->encap.sport) ||
591 	    nla_put_be16(skb, IFLA_IPTUN_ENCAP_DPORT,
592 			 tunnel->encap.dport) ||
593 	    nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS,
594 			tunnel->encap.flags))
595 		goto nla_put_failure;
596 
597 	if (tunnel->collect_md)
598 		if (nla_put_flag(skb, IFLA_IPTUN_COLLECT_METADATA))
599 			goto nla_put_failure;
600 	return 0;
601 
602 nla_put_failure:
603 	return -EMSGSIZE;
604 }
605 
606 static const struct nla_policy ipip_policy[IFLA_IPTUN_MAX + 1] = {
607 	[IFLA_IPTUN_LINK]		= { .type = NLA_U32 },
608 	[IFLA_IPTUN_LOCAL]		= { .type = NLA_U32 },
609 	[IFLA_IPTUN_REMOTE]		= { .type = NLA_U32 },
610 	[IFLA_IPTUN_TTL]		= { .type = NLA_U8 },
611 	[IFLA_IPTUN_TOS]		= { .type = NLA_U8 },
612 	[IFLA_IPTUN_PROTO]		= { .type = NLA_U8 },
613 	[IFLA_IPTUN_PMTUDISC]		= { .type = NLA_U8 },
614 	[IFLA_IPTUN_ENCAP_TYPE]		= { .type = NLA_U16 },
615 	[IFLA_IPTUN_ENCAP_FLAGS]	= { .type = NLA_U16 },
616 	[IFLA_IPTUN_ENCAP_SPORT]	= { .type = NLA_U16 },
617 	[IFLA_IPTUN_ENCAP_DPORT]	= { .type = NLA_U16 },
618 	[IFLA_IPTUN_COLLECT_METADATA]	= { .type = NLA_FLAG },
619 	[IFLA_IPTUN_FWMARK]		= { .type = NLA_U32 },
620 };
621 
622 static struct rtnl_link_ops ipip_link_ops __read_mostly = {
623 	.kind		= "ipip",
624 	.maxtype	= IFLA_IPTUN_MAX,
625 	.policy		= ipip_policy,
626 	.priv_size	= sizeof(struct ip_tunnel),
627 	.setup		= ipip_tunnel_setup,
628 	.validate	= ipip_tunnel_validate,
629 	.newlink	= ipip_newlink,
630 	.changelink	= ipip_changelink,
631 	.dellink	= ip_tunnel_dellink,
632 	.get_size	= ipip_get_size,
633 	.fill_info	= ipip_fill_info,
634 	.get_link_net	= ip_tunnel_get_link_net,
635 };
636 
637 static struct xfrm_tunnel ipip_handler __read_mostly = {
638 	.handler	=	ipip_rcv,
639 	.err_handler	=	ipip_err,
640 	.priority	=	1,
641 };
642 
643 #if IS_ENABLED(CONFIG_MPLS)
644 static struct xfrm_tunnel mplsip_handler __read_mostly = {
645 	.handler	=	mplsip_rcv,
646 	.err_handler	=	ipip_err,
647 	.priority	=	1,
648 };
649 #endif
650 
651 static int __net_init ipip_init_net(struct net *net)
652 {
653 	return ip_tunnel_init_net(net, ipip_net_id, &ipip_link_ops, "tunl0");
654 }
655 
656 static void __net_exit ipip_exit_batch_net(struct list_head *list_net)
657 {
658 	ip_tunnel_delete_nets(list_net, ipip_net_id, &ipip_link_ops);
659 }
660 
661 static struct pernet_operations ipip_net_ops = {
662 	.init = ipip_init_net,
663 	.exit_batch = ipip_exit_batch_net,
664 	.id   = &ipip_net_id,
665 	.size = sizeof(struct ip_tunnel_net),
666 };
667 
668 static int __init ipip_init(void)
669 {
670 	int err;
671 
672 	pr_info("ipip: IPv4 and MPLS over IPv4 tunneling driver\n");
673 
674 	err = register_pernet_device(&ipip_net_ops);
675 	if (err < 0)
676 		return err;
677 	err = xfrm4_tunnel_register(&ipip_handler, AF_INET);
678 	if (err < 0) {
679 		pr_info("%s: can't register tunnel\n", __func__);
680 		goto xfrm_tunnel_ipip_failed;
681 	}
682 #if IS_ENABLED(CONFIG_MPLS)
683 	err = xfrm4_tunnel_register(&mplsip_handler, AF_MPLS);
684 	if (err < 0) {
685 		pr_info("%s: can't register tunnel\n", __func__);
686 		goto xfrm_tunnel_mplsip_failed;
687 	}
688 #endif
689 	err = rtnl_link_register(&ipip_link_ops);
690 	if (err < 0)
691 		goto rtnl_link_failed;
692 
693 out:
694 	return err;
695 
696 rtnl_link_failed:
697 #if IS_ENABLED(CONFIG_MPLS)
698 	xfrm4_tunnel_deregister(&mplsip_handler, AF_INET);
699 xfrm_tunnel_mplsip_failed:
700 
701 #endif
702 	xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
703 xfrm_tunnel_ipip_failed:
704 	unregister_pernet_device(&ipip_net_ops);
705 	goto out;
706 }
707 
708 static void __exit ipip_fini(void)
709 {
710 	rtnl_link_unregister(&ipip_link_ops);
711 	if (xfrm4_tunnel_deregister(&ipip_handler, AF_INET))
712 		pr_info("%s: can't deregister tunnel\n", __func__);
713 #if IS_ENABLED(CONFIG_MPLS)
714 	if (xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS))
715 		pr_info("%s: can't deregister tunnel\n", __func__);
716 #endif
717 	unregister_pernet_device(&ipip_net_ops);
718 }
719 
720 module_init(ipip_init);
721 module_exit(ipip_fini);
722 MODULE_LICENSE("GPL");
723 MODULE_ALIAS_RTNL_LINK("ipip");
724 MODULE_ALIAS_NETDEV("tunl0");
725