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1 /*
2  *	Linux NET3:	IP/IP protocol decoder.
3  *
4  *	Authors:
5  *		Sam Lantinga (slouken@cs.ucdavis.edu)  02/01/95
6  *
7  *	Fixes:
8  *		Alan Cox	:	Merged and made usable non modular (its so tiny its silly as
9  *					a module taking up 2 pages).
10  *		Alan Cox	: 	Fixed bug with 1.3.18 and IPIP not working (now needs to set skb->h.iph)
11  *					to keep ip_forward happy.
12  *		Alan Cox	:	More fixes for 1.3.21, and firewall fix. Maybe this will work soon 8).
13  *		Kai Schulte	:	Fixed #defines for IP_FIREWALL->FIREWALL
14  *              David Woodhouse :       Perform some basic ICMP handling.
15  *                                      IPIP Routing without decapsulation.
16  *              Carlos Picoto   :       GRE over IP support
17  *		Alexey Kuznetsov:	Reworked. Really, now it is truncated version of ipv4/ip_gre.c.
18  *					I do not want to merge them together.
19  *
20  *	This program is free software; you can redistribute it and/or
21  *	modify it under the terms of the GNU General Public License
22  *	as published by the Free Software Foundation; either version
23  *	2 of the License, or (at your option) any later version.
24  *
25  */
26 
27 /* tunnel.c: an IP tunnel driver
28 
29 	The purpose of this driver is to provide an IP tunnel through
30 	which you can tunnel network traffic transparently across subnets.
31 
32 	This was written by looking at Nick Holloway's dummy driver
33 	Thanks for the great code!
34 
35 		-Sam Lantinga	(slouken@cs.ucdavis.edu)  02/01/95
36 
37 	Minor tweaks:
38 		Cleaned up the code a little and added some pre-1.3.0 tweaks.
39 		dev->hard_header/hard_header_len changed to use no headers.
40 		Comments/bracketing tweaked.
41 		Made the tunnels use dev->name not tunnel: when error reporting.
42 		Added tx_dropped stat
43 
44 		-Alan Cox	(alan@lxorguk.ukuu.org.uk) 21 March 95
45 
46 	Reworked:
47 		Changed to tunnel to destination gateway in addition to the
48 			tunnel's pointopoint address
49 		Almost completely rewritten
50 		Note:  There is currently no firewall or ICMP handling done.
51 
52 		-Sam Lantinga	(slouken@cs.ucdavis.edu) 02/13/96
53 
54 */
55 
56 /* Things I wish I had known when writing the tunnel driver:
57 
58 	When the tunnel_xmit() function is called, the skb contains the
59 	packet to be sent (plus a great deal of extra info), and dev
60 	contains the tunnel device that _we_ are.
61 
62 	When we are passed a packet, we are expected to fill in the
63 	source address with our source IP address.
64 
65 	What is the proper way to allocate, copy and free a buffer?
66 	After you allocate it, it is a "0 length" chunk of memory
67 	starting at zero.  If you want to add headers to the buffer
68 	later, you'll have to call "skb_reserve(skb, amount)" with
69 	the amount of memory you want reserved.  Then, you call
70 	"skb_put(skb, amount)" with the amount of space you want in
71 	the buffer.  skb_put() returns a pointer to the top (#0) of
72 	that buffer.  skb->len is set to the amount of space you have
73 	"allocated" with skb_put().  You can then write up to skb->len
74 	bytes to that buffer.  If you need more, you can call skb_put()
75 	again with the additional amount of space you need.  You can
76 	find out how much more space you can allocate by calling
77 	"skb_tailroom(skb)".
78 	Now, to add header space, call "skb_push(skb, header_len)".
79 	This creates space at the beginning of the buffer and returns
80 	a pointer to this new space.  If later you need to strip a
81 	header from a buffer, call "skb_pull(skb, header_len)".
82 	skb_headroom() will return how much space is left at the top
83 	of the buffer (before the main data).  Remember, this headroom
84 	space must be reserved before the skb_put() function is called.
85 	*/
86 
87 /*
88    This version of net/ipv4/ipip.c is cloned of net/ipv4/ip_gre.c
89 
90    For comments look at net/ipv4/ip_gre.c --ANK
91  */
92 
93 
94 #include <linux/capability.h>
95 #include <linux/module.h>
96 #include <linux/types.h>
97 #include <linux/kernel.h>
98 #include <linux/slab.h>
99 #include <asm/uaccess.h>
100 #include <linux/skbuff.h>
101 #include <linux/netdevice.h>
102 #include <linux/in.h>
103 #include <linux/tcp.h>
104 #include <linux/udp.h>
105 #include <linux/if_arp.h>
106 #include <linux/init.h>
107 #include <linux/netfilter_ipv4.h>
108 #include <linux/if_ether.h>
109 
110 #include <net/sock.h>
111 #include <net/ip.h>
112 #include <net/icmp.h>
113 #include <net/ip_tunnels.h>
114 #include <net/inet_ecn.h>
115 #include <net/xfrm.h>
116 #include <net/net_namespace.h>
117 #include <net/netns/generic.h>
118 #include <net/dst_metadata.h>
119 
120 static bool log_ecn_error = true;
121 module_param(log_ecn_error, bool, 0644);
122 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
123 
124 static int ipip_net_id __read_mostly;
125 
126 static int ipip_tunnel_init(struct net_device *dev);
127 static struct rtnl_link_ops ipip_link_ops __read_mostly;
128 
ipip_err(struct sk_buff * skb,u32 info)129 static int ipip_err(struct sk_buff *skb, u32 info)
130 {
131 	/* All the routers (except for Linux) return only
132 	 * 8 bytes of packet payload. It means, that precise relaying of
133 	 * ICMP in the real Internet is absolutely infeasible.
134 	 */
135 	struct net *net = dev_net(skb->dev);
136 	struct ip_tunnel_net *itn = net_generic(net, ipip_net_id);
137 	const struct iphdr *iph = (const struct iphdr *)skb->data;
138 	const int type = icmp_hdr(skb)->type;
139 	const int code = icmp_hdr(skb)->code;
140 	struct ip_tunnel *t;
141 	int err = 0;
142 
143 	switch (type) {
144 	case ICMP_DEST_UNREACH:
145 		switch (code) {
146 		case ICMP_SR_FAILED:
147 			/* Impossible event. */
148 			goto out;
149 		default:
150 			/* All others are translated to HOST_UNREACH.
151 			 * rfc2003 contains "deep thoughts" about NET_UNREACH,
152 			 * I believe they are just ether pollution. --ANK
153 			 */
154 			break;
155 		}
156 		break;
157 
158 	case ICMP_TIME_EXCEEDED:
159 		if (code != ICMP_EXC_TTL)
160 			goto out;
161 		break;
162 
163 	case ICMP_REDIRECT:
164 		break;
165 
166 	default:
167 		goto out;
168 	}
169 
170 	t = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY,
171 			     iph->daddr, iph->saddr, 0);
172 	if (!t) {
173 		err = -ENOENT;
174 		goto out;
175 	}
176 
177 	if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
178 		ipv4_update_pmtu(skb, net, info, t->parms.link, 0,
179 				 iph->protocol, 0);
180 		goto out;
181 	}
182 
183 	if (type == ICMP_REDIRECT) {
184 		ipv4_redirect(skb, net, t->parms.link, 0, iph->protocol, 0);
185 		goto out;
186 	}
187 
188 	if (t->parms.iph.daddr == 0) {
189 		err = -ENOENT;
190 		goto out;
191 	}
192 
193 	if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
194 		goto out;
195 
196 	if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
197 		t->err_count++;
198 	else
199 		t->err_count = 1;
200 	t->err_time = jiffies;
201 
202 out:
203 	return err;
204 }
205 
206 static const struct tnl_ptk_info ipip_tpi = {
207 	/* no tunnel info required for ipip. */
208 	.proto = htons(ETH_P_IP),
209 };
210 
211 #if IS_ENABLED(CONFIG_MPLS)
212 static const struct tnl_ptk_info mplsip_tpi = {
213 	/* no tunnel info required for mplsip. */
214 	.proto = htons(ETH_P_MPLS_UC),
215 };
216 #endif
217 
ipip_tunnel_rcv(struct sk_buff * skb,u8 ipproto)218 static int ipip_tunnel_rcv(struct sk_buff *skb, u8 ipproto)
219 {
220 	struct net *net = dev_net(skb->dev);
221 	struct ip_tunnel_net *itn = net_generic(net, ipip_net_id);
222 	struct metadata_dst *tun_dst = NULL;
223 	struct ip_tunnel *tunnel;
224 	const struct iphdr *iph;
225 
226 	iph = ip_hdr(skb);
227 	tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY,
228 			iph->saddr, 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 			tun_dst = ip_tun_rx_dst(skb, 0, 0, 0);
248 			if (!tun_dst)
249 				return 0;
250 		}
251 		return ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error);
252 	}
253 
254 	return -1;
255 
256 drop:
257 	kfree_skb(skb);
258 	return 0;
259 }
260 
ipip_rcv(struct sk_buff * skb)261 static int ipip_rcv(struct sk_buff *skb)
262 {
263 	return ipip_tunnel_rcv(skb, IPPROTO_IPIP);
264 }
265 
266 #if IS_ENABLED(CONFIG_MPLS)
mplsip_rcv(struct sk_buff * skb)267 static int mplsip_rcv(struct sk_buff *skb)
268 {
269 	return ipip_tunnel_rcv(skb, IPPROTO_MPLS);
270 }
271 #endif
272 
273 /*
274  *	This function assumes it is being called from dev_queue_xmit()
275  *	and that skb is filled properly by that function.
276  */
ipip_tunnel_xmit(struct sk_buff * skb,struct net_device * dev)277 static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb,
278 				    struct net_device *dev)
279 {
280 	struct ip_tunnel *tunnel = netdev_priv(dev);
281 	const struct iphdr  *tiph = &tunnel->parms.iph;
282 	u8 ipproto;
283 
284 	switch (skb->protocol) {
285 	case htons(ETH_P_IP):
286 		ipproto = IPPROTO_IPIP;
287 		break;
288 #if IS_ENABLED(CONFIG_MPLS)
289 	case htons(ETH_P_MPLS_UC):
290 		ipproto = IPPROTO_MPLS;
291 		break;
292 #endif
293 	default:
294 		goto tx_error;
295 	}
296 
297 	if (tiph->protocol != ipproto && tiph->protocol != 0)
298 		goto tx_error;
299 
300 	if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP4))
301 		goto tx_error;
302 
303 	skb_set_inner_ipproto(skb, ipproto);
304 
305 	if (tunnel->collect_md)
306 		ip_md_tunnel_xmit(skb, dev, ipproto);
307 	else
308 		ip_tunnel_xmit(skb, dev, tiph, ipproto);
309 	return NETDEV_TX_OK;
310 
311 tx_error:
312 	kfree_skb(skb);
313 
314 	dev->stats.tx_errors++;
315 	return NETDEV_TX_OK;
316 }
317 
ipip_tunnel_ioctl_verify_protocol(u8 ipproto)318 static bool ipip_tunnel_ioctl_verify_protocol(u8 ipproto)
319 {
320 	switch (ipproto) {
321 	case 0:
322 	case IPPROTO_IPIP:
323 #if IS_ENABLED(CONFIG_MPLS)
324 	case IPPROTO_MPLS:
325 #endif
326 		return true;
327 	}
328 
329 	return false;
330 }
331 
332 static int
ipip_tunnel_ioctl(struct net_device * dev,struct ifreq * ifr,int cmd)333 ipip_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
334 {
335 	int err = 0;
336 	struct ip_tunnel_parm p;
337 
338 	if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
339 		return -EFAULT;
340 
341 	if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) {
342 		if (p.iph.version != 4 ||
343 		    !ipip_tunnel_ioctl_verify_protocol(p.iph.protocol) ||
344 		    p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)))
345 			return -EINVAL;
346 	}
347 
348 	p.i_key = p.o_key = 0;
349 	p.i_flags = p.o_flags = 0;
350 	err = ip_tunnel_ioctl(dev, &p, cmd);
351 	if (err)
352 		return err;
353 
354 	if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
355 		return -EFAULT;
356 
357 	return 0;
358 }
359 
360 static const struct net_device_ops ipip_netdev_ops = {
361 	.ndo_init       = ipip_tunnel_init,
362 	.ndo_uninit     = ip_tunnel_uninit,
363 	.ndo_start_xmit	= ipip_tunnel_xmit,
364 	.ndo_do_ioctl	= ipip_tunnel_ioctl,
365 	.ndo_change_mtu = ip_tunnel_change_mtu,
366 	.ndo_get_stats64 = ip_tunnel_get_stats64,
367 	.ndo_get_iflink = ip_tunnel_get_iflink,
368 };
369 
370 #define IPIP_FEATURES (NETIF_F_SG |		\
371 		       NETIF_F_FRAGLIST |	\
372 		       NETIF_F_HIGHDMA |	\
373 		       NETIF_F_GSO_SOFTWARE |	\
374 		       NETIF_F_HW_CSUM)
375 
ipip_tunnel_setup(struct net_device * dev)376 static void ipip_tunnel_setup(struct net_device *dev)
377 {
378 	dev->netdev_ops		= &ipip_netdev_ops;
379 
380 	dev->type		= ARPHRD_TUNNEL;
381 	dev->flags		= IFF_NOARP;
382 	dev->addr_len		= 4;
383 	dev->features		|= NETIF_F_LLTX;
384 	netif_keep_dst(dev);
385 
386 	dev->features		|= IPIP_FEATURES;
387 	dev->hw_features	|= IPIP_FEATURES;
388 	ip_tunnel_setup(dev, ipip_net_id);
389 }
390 
ipip_tunnel_init(struct net_device * dev)391 static int ipip_tunnel_init(struct net_device *dev)
392 {
393 	struct ip_tunnel *tunnel = netdev_priv(dev);
394 
395 	memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
396 	memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
397 
398 	tunnel->tun_hlen = 0;
399 	tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen;
400 	return ip_tunnel_init(dev);
401 }
402 
ipip_tunnel_validate(struct nlattr * tb[],struct nlattr * data[])403 static int ipip_tunnel_validate(struct nlattr *tb[], struct nlattr *data[])
404 {
405 	u8 proto;
406 
407 	if (!data || !data[IFLA_IPTUN_PROTO])
408 		return 0;
409 
410 	proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
411 	if (proto != IPPROTO_IPIP && proto != IPPROTO_MPLS && proto != 0)
412 		return -EINVAL;
413 
414 	return 0;
415 }
416 
ipip_netlink_parms(struct nlattr * data[],struct ip_tunnel_parm * parms,bool * collect_md)417 static void ipip_netlink_parms(struct nlattr *data[],
418 			       struct ip_tunnel_parm *parms, bool *collect_md)
419 {
420 	memset(parms, 0, sizeof(*parms));
421 
422 	parms->iph.version = 4;
423 	parms->iph.protocol = IPPROTO_IPIP;
424 	parms->iph.ihl = 5;
425 	*collect_md = false;
426 
427 	if (!data)
428 		return;
429 
430 	if (data[IFLA_IPTUN_LINK])
431 		parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
432 
433 	if (data[IFLA_IPTUN_LOCAL])
434 		parms->iph.saddr = nla_get_in_addr(data[IFLA_IPTUN_LOCAL]);
435 
436 	if (data[IFLA_IPTUN_REMOTE])
437 		parms->iph.daddr = nla_get_in_addr(data[IFLA_IPTUN_REMOTE]);
438 
439 	if (data[IFLA_IPTUN_TTL]) {
440 		parms->iph.ttl = nla_get_u8(data[IFLA_IPTUN_TTL]);
441 		if (parms->iph.ttl)
442 			parms->iph.frag_off = htons(IP_DF);
443 	}
444 
445 	if (data[IFLA_IPTUN_TOS])
446 		parms->iph.tos = nla_get_u8(data[IFLA_IPTUN_TOS]);
447 
448 	if (data[IFLA_IPTUN_PROTO])
449 		parms->iph.protocol = nla_get_u8(data[IFLA_IPTUN_PROTO]);
450 
451 	if (!data[IFLA_IPTUN_PMTUDISC] || nla_get_u8(data[IFLA_IPTUN_PMTUDISC]))
452 		parms->iph.frag_off = htons(IP_DF);
453 
454 	if (data[IFLA_IPTUN_COLLECT_METADATA])
455 		*collect_md = true;
456 }
457 
458 /* This function returns true when ENCAP attributes are present in the nl msg */
ipip_netlink_encap_parms(struct nlattr * data[],struct ip_tunnel_encap * ipencap)459 static bool ipip_netlink_encap_parms(struct nlattr *data[],
460 				     struct ip_tunnel_encap *ipencap)
461 {
462 	bool ret = false;
463 
464 	memset(ipencap, 0, sizeof(*ipencap));
465 
466 	if (!data)
467 		return ret;
468 
469 	if (data[IFLA_IPTUN_ENCAP_TYPE]) {
470 		ret = true;
471 		ipencap->type = nla_get_u16(data[IFLA_IPTUN_ENCAP_TYPE]);
472 	}
473 
474 	if (data[IFLA_IPTUN_ENCAP_FLAGS]) {
475 		ret = true;
476 		ipencap->flags = nla_get_u16(data[IFLA_IPTUN_ENCAP_FLAGS]);
477 	}
478 
479 	if (data[IFLA_IPTUN_ENCAP_SPORT]) {
480 		ret = true;
481 		ipencap->sport = nla_get_be16(data[IFLA_IPTUN_ENCAP_SPORT]);
482 	}
483 
484 	if (data[IFLA_IPTUN_ENCAP_DPORT]) {
485 		ret = true;
486 		ipencap->dport = nla_get_be16(data[IFLA_IPTUN_ENCAP_DPORT]);
487 	}
488 
489 	return ret;
490 }
491 
ipip_newlink(struct net * src_net,struct net_device * dev,struct nlattr * tb[],struct nlattr * data[])492 static int ipip_newlink(struct net *src_net, struct net_device *dev,
493 			struct nlattr *tb[], struct nlattr *data[])
494 {
495 	struct ip_tunnel *t = netdev_priv(dev);
496 	struct ip_tunnel_parm p;
497 	struct ip_tunnel_encap ipencap;
498 
499 	if (ipip_netlink_encap_parms(data, &ipencap)) {
500 		int err = ip_tunnel_encap_setup(t, &ipencap);
501 
502 		if (err < 0)
503 			return err;
504 	}
505 
506 	ipip_netlink_parms(data, &p, &t->collect_md);
507 	return ip_tunnel_newlink(dev, tb, &p);
508 }
509 
ipip_changelink(struct net_device * dev,struct nlattr * tb[],struct nlattr * data[])510 static int ipip_changelink(struct net_device *dev, struct nlattr *tb[],
511 			   struct nlattr *data[])
512 {
513 	struct ip_tunnel_parm p;
514 	struct ip_tunnel_encap ipencap;
515 	bool collect_md;
516 
517 	if (ipip_netlink_encap_parms(data, &ipencap)) {
518 		struct ip_tunnel *t = netdev_priv(dev);
519 		int err = ip_tunnel_encap_setup(t, &ipencap);
520 
521 		if (err < 0)
522 			return err;
523 	}
524 
525 	ipip_netlink_parms(data, &p, &collect_md);
526 	if (collect_md)
527 		return -EINVAL;
528 
529 	if (((dev->flags & IFF_POINTOPOINT) && !p.iph.daddr) ||
530 	    (!(dev->flags & IFF_POINTOPOINT) && p.iph.daddr))
531 		return -EINVAL;
532 
533 	return ip_tunnel_changelink(dev, tb, &p);
534 }
535 
ipip_get_size(const struct net_device * dev)536 static size_t ipip_get_size(const struct net_device *dev)
537 {
538 	return
539 		/* IFLA_IPTUN_LINK */
540 		nla_total_size(4) +
541 		/* IFLA_IPTUN_LOCAL */
542 		nla_total_size(4) +
543 		/* IFLA_IPTUN_REMOTE */
544 		nla_total_size(4) +
545 		/* IFLA_IPTUN_TTL */
546 		nla_total_size(1) +
547 		/* IFLA_IPTUN_TOS */
548 		nla_total_size(1) +
549 		/* IFLA_IPTUN_PROTO */
550 		nla_total_size(1) +
551 		/* IFLA_IPTUN_PMTUDISC */
552 		nla_total_size(1) +
553 		/* IFLA_IPTUN_ENCAP_TYPE */
554 		nla_total_size(2) +
555 		/* IFLA_IPTUN_ENCAP_FLAGS */
556 		nla_total_size(2) +
557 		/* IFLA_IPTUN_ENCAP_SPORT */
558 		nla_total_size(2) +
559 		/* IFLA_IPTUN_ENCAP_DPORT */
560 		nla_total_size(2) +
561 		/* IFLA_IPTUN_COLLECT_METADATA */
562 		nla_total_size(0) +
563 		0;
564 }
565 
ipip_fill_info(struct sk_buff * skb,const struct net_device * dev)566 static int ipip_fill_info(struct sk_buff *skb, const struct net_device *dev)
567 {
568 	struct ip_tunnel *tunnel = netdev_priv(dev);
569 	struct ip_tunnel_parm *parm = &tunnel->parms;
570 
571 	if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
572 	    nla_put_in_addr(skb, IFLA_IPTUN_LOCAL, parm->iph.saddr) ||
573 	    nla_put_in_addr(skb, IFLA_IPTUN_REMOTE, parm->iph.daddr) ||
574 	    nla_put_u8(skb, IFLA_IPTUN_TTL, parm->iph.ttl) ||
575 	    nla_put_u8(skb, IFLA_IPTUN_TOS, parm->iph.tos) ||
576 	    nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->iph.protocol) ||
577 	    nla_put_u8(skb, IFLA_IPTUN_PMTUDISC,
578 		       !!(parm->iph.frag_off & htons(IP_DF))))
579 		goto nla_put_failure;
580 
581 	if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE,
582 			tunnel->encap.type) ||
583 	    nla_put_be16(skb, IFLA_IPTUN_ENCAP_SPORT,
584 			 tunnel->encap.sport) ||
585 	    nla_put_be16(skb, IFLA_IPTUN_ENCAP_DPORT,
586 			 tunnel->encap.dport) ||
587 	    nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS,
588 			tunnel->encap.flags))
589 		goto nla_put_failure;
590 
591 	if (tunnel->collect_md)
592 		if (nla_put_flag(skb, IFLA_IPTUN_COLLECT_METADATA))
593 			goto nla_put_failure;
594 	return 0;
595 
596 nla_put_failure:
597 	return -EMSGSIZE;
598 }
599 
600 static const struct nla_policy ipip_policy[IFLA_IPTUN_MAX + 1] = {
601 	[IFLA_IPTUN_LINK]		= { .type = NLA_U32 },
602 	[IFLA_IPTUN_LOCAL]		= { .type = NLA_U32 },
603 	[IFLA_IPTUN_REMOTE]		= { .type = NLA_U32 },
604 	[IFLA_IPTUN_TTL]		= { .type = NLA_U8 },
605 	[IFLA_IPTUN_TOS]		= { .type = NLA_U8 },
606 	[IFLA_IPTUN_PROTO]		= { .type = NLA_U8 },
607 	[IFLA_IPTUN_PMTUDISC]		= { .type = NLA_U8 },
608 	[IFLA_IPTUN_ENCAP_TYPE]		= { .type = NLA_U16 },
609 	[IFLA_IPTUN_ENCAP_FLAGS]	= { .type = NLA_U16 },
610 	[IFLA_IPTUN_ENCAP_SPORT]	= { .type = NLA_U16 },
611 	[IFLA_IPTUN_ENCAP_DPORT]	= { .type = NLA_U16 },
612 	[IFLA_IPTUN_COLLECT_METADATA]	= { .type = NLA_FLAG },
613 };
614 
615 static struct rtnl_link_ops ipip_link_ops __read_mostly = {
616 	.kind		= "ipip",
617 	.maxtype	= IFLA_IPTUN_MAX,
618 	.policy		= ipip_policy,
619 	.priv_size	= sizeof(struct ip_tunnel),
620 	.setup		= ipip_tunnel_setup,
621 	.validate	= ipip_tunnel_validate,
622 	.newlink	= ipip_newlink,
623 	.changelink	= ipip_changelink,
624 	.dellink	= ip_tunnel_dellink,
625 	.get_size	= ipip_get_size,
626 	.fill_info	= ipip_fill_info,
627 	.get_link_net	= ip_tunnel_get_link_net,
628 };
629 
630 static struct xfrm_tunnel ipip_handler __read_mostly = {
631 	.handler	=	ipip_rcv,
632 	.err_handler	=	ipip_err,
633 	.priority	=	1,
634 };
635 
636 #if IS_ENABLED(CONFIG_MPLS)
637 static struct xfrm_tunnel mplsip_handler __read_mostly = {
638 	.handler	=	mplsip_rcv,
639 	.err_handler	=	ipip_err,
640 	.priority	=	1,
641 };
642 #endif
643 
ipip_init_net(struct net * net)644 static int __net_init ipip_init_net(struct net *net)
645 {
646 	return ip_tunnel_init_net(net, ipip_net_id, &ipip_link_ops, "tunl0");
647 }
648 
ipip_exit_net(struct net * net)649 static void __net_exit ipip_exit_net(struct net *net)
650 {
651 	struct ip_tunnel_net *itn = net_generic(net, ipip_net_id);
652 	ip_tunnel_delete_net(itn, &ipip_link_ops);
653 }
654 
655 static struct pernet_operations ipip_net_ops = {
656 	.init = ipip_init_net,
657 	.exit = ipip_exit_net,
658 	.id   = &ipip_net_id,
659 	.size = sizeof(struct ip_tunnel_net),
660 };
661 
ipip_init(void)662 static int __init ipip_init(void)
663 {
664 	int err;
665 
666 	pr_info("ipip: IPv4 and MPLS over IPv4 tunneling driver\n");
667 
668 	err = register_pernet_device(&ipip_net_ops);
669 	if (err < 0)
670 		return err;
671 	err = xfrm4_tunnel_register(&ipip_handler, AF_INET);
672 	if (err < 0) {
673 		pr_info("%s: can't register tunnel\n", __func__);
674 		goto xfrm_tunnel_ipip_failed;
675 	}
676 #if IS_ENABLED(CONFIG_MPLS)
677 	err = xfrm4_tunnel_register(&mplsip_handler, AF_MPLS);
678 	if (err < 0) {
679 		pr_info("%s: can't register tunnel\n", __func__);
680 		goto xfrm_tunnel_mplsip_failed;
681 	}
682 #endif
683 	err = rtnl_link_register(&ipip_link_ops);
684 	if (err < 0)
685 		goto rtnl_link_failed;
686 
687 out:
688 	return err;
689 
690 rtnl_link_failed:
691 #if IS_ENABLED(CONFIG_MPLS)
692 	xfrm4_tunnel_deregister(&mplsip_handler, AF_INET);
693 xfrm_tunnel_mplsip_failed:
694 
695 #endif
696 	xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
697 xfrm_tunnel_ipip_failed:
698 	unregister_pernet_device(&ipip_net_ops);
699 	goto out;
700 }
701 
ipip_fini(void)702 static void __exit ipip_fini(void)
703 {
704 	rtnl_link_unregister(&ipip_link_ops);
705 	if (xfrm4_tunnel_deregister(&ipip_handler, AF_INET))
706 		pr_info("%s: can't deregister tunnel\n", __func__);
707 #if IS_ENABLED(CONFIG_MPLS)
708 	if (xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS))
709 		pr_info("%s: can't deregister tunnel\n", __func__);
710 #endif
711 	unregister_pernet_device(&ipip_net_ops);
712 }
713 
714 module_init(ipip_init);
715 module_exit(ipip_fini);
716 MODULE_LICENSE("GPL");
717 MODULE_ALIAS_RTNL_LINK("ipip");
718 MODULE_ALIAS_NETDEV("tunl0");
719