xref: /openbmc/linux/net/ipv4/ip_vti.c (revision 600a711c)
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/mroute.h>
34 #include <linux/init.h>
35 #include <linux/netfilter_ipv4.h>
36 #include <linux/if_ether.h>
37 
38 #include <net/sock.h>
39 #include <net/ip.h>
40 #include <net/icmp.h>
41 #include <net/ipip.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 #define HASH_SIZE  16
48 #define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&(HASH_SIZE-1))
49 
50 static struct rtnl_link_ops vti_link_ops __read_mostly;
51 
52 static int vti_net_id __read_mostly;
53 struct vti_net {
54 	struct ip_tunnel __rcu *tunnels_r_l[HASH_SIZE];
55 	struct ip_tunnel __rcu *tunnels_r[HASH_SIZE];
56 	struct ip_tunnel __rcu *tunnels_l[HASH_SIZE];
57 	struct ip_tunnel __rcu *tunnels_wc[1];
58 	struct ip_tunnel __rcu **tunnels[4];
59 
60 	struct net_device *fb_tunnel_dev;
61 };
62 
63 static int vti_fb_tunnel_init(struct net_device *dev);
64 static int vti_tunnel_init(struct net_device *dev);
65 static void vti_tunnel_setup(struct net_device *dev);
66 static void vti_dev_free(struct net_device *dev);
67 static int vti_tunnel_bind_dev(struct net_device *dev);
68 
69 /* Locking : hash tables are protected by RCU and RTNL */
70 
71 #define for_each_ip_tunnel_rcu(start) \
72 	for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
73 
74 /* often modified stats are per cpu, other are shared (netdev->stats) */
75 struct pcpu_tstats {
76 	u64	rx_packets;
77 	u64	rx_bytes;
78 	u64	tx_packets;
79 	u64	tx_bytes;
80 	struct	u64_stats_sync	syncp;
81 };
82 
83 #define VTI_XMIT(stats1, stats2) do {				\
84 	int err;						\
85 	int pkt_len = skb->len;					\
86 	err = dst_output(skb);					\
87 	if (net_xmit_eval(err) == 0) {				\
88 		u64_stats_update_begin(&(stats1)->syncp);	\
89 		(stats1)->tx_bytes += pkt_len;			\
90 		(stats1)->tx_packets++;				\
91 		u64_stats_update_end(&(stats1)->syncp);		\
92 	} else {						\
93 		(stats2)->tx_errors++;				\
94 		(stats2)->tx_aborted_errors++;			\
95 	}							\
96 } while (0)
97 
98 
99 static struct rtnl_link_stats64 *vti_get_stats64(struct net_device *dev,
100 						 struct rtnl_link_stats64 *tot)
101 {
102 	int i;
103 
104 	for_each_possible_cpu(i) {
105 		const struct pcpu_tstats *tstats = per_cpu_ptr(dev->tstats, i);
106 		u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
107 		unsigned int start;
108 
109 		do {
110 			start = u64_stats_fetch_begin_bh(&tstats->syncp);
111 			rx_packets = tstats->rx_packets;
112 			tx_packets = tstats->tx_packets;
113 			rx_bytes = tstats->rx_bytes;
114 			tx_bytes = tstats->tx_bytes;
115 		} while (u64_stats_fetch_retry_bh(&tstats->syncp, start));
116 
117 		tot->rx_packets += rx_packets;
118 		tot->tx_packets += tx_packets;
119 		tot->rx_bytes   += rx_bytes;
120 		tot->tx_bytes   += tx_bytes;
121 	}
122 
123 	tot->multicast = dev->stats.multicast;
124 	tot->rx_crc_errors = dev->stats.rx_crc_errors;
125 	tot->rx_fifo_errors = dev->stats.rx_fifo_errors;
126 	tot->rx_length_errors = dev->stats.rx_length_errors;
127 	tot->rx_errors = dev->stats.rx_errors;
128 	tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
129 	tot->tx_carrier_errors = dev->stats.tx_carrier_errors;
130 	tot->tx_dropped = dev->stats.tx_dropped;
131 	tot->tx_aborted_errors = dev->stats.tx_aborted_errors;
132 	tot->tx_errors = dev->stats.tx_errors;
133 
134 	return tot;
135 }
136 
137 static struct ip_tunnel *vti_tunnel_lookup(struct net *net,
138 					   __be32 remote, __be32 local)
139 {
140 	unsigned h0 = HASH(remote);
141 	unsigned h1 = HASH(local);
142 	struct ip_tunnel *t;
143 	struct vti_net *ipn = net_generic(net, vti_net_id);
144 
145 	for_each_ip_tunnel_rcu(ipn->tunnels_r_l[h0 ^ h1])
146 		if (local == t->parms.iph.saddr &&
147 		    remote == t->parms.iph.daddr && (t->dev->flags&IFF_UP))
148 			return t;
149 	for_each_ip_tunnel_rcu(ipn->tunnels_r[h0])
150 		if (remote == t->parms.iph.daddr && (t->dev->flags&IFF_UP))
151 			return t;
152 
153 	for_each_ip_tunnel_rcu(ipn->tunnels_l[h1])
154 		if (local == t->parms.iph.saddr && (t->dev->flags&IFF_UP))
155 			return t;
156 
157 	for_each_ip_tunnel_rcu(ipn->tunnels_wc[0])
158 		if (t && (t->dev->flags&IFF_UP))
159 			return t;
160 	return NULL;
161 }
162 
163 static struct ip_tunnel __rcu **__vti_bucket(struct vti_net *ipn,
164 					     struct ip_tunnel_parm *parms)
165 {
166 	__be32 remote = parms->iph.daddr;
167 	__be32 local = parms->iph.saddr;
168 	unsigned h = 0;
169 	int prio = 0;
170 
171 	if (remote) {
172 		prio |= 2;
173 		h ^= HASH(remote);
174 	}
175 	if (local) {
176 		prio |= 1;
177 		h ^= HASH(local);
178 	}
179 	return &ipn->tunnels[prio][h];
180 }
181 
182 static inline struct ip_tunnel __rcu **vti_bucket(struct vti_net *ipn,
183 						  struct ip_tunnel *t)
184 {
185 	return __vti_bucket(ipn, &t->parms);
186 }
187 
188 static void vti_tunnel_unlink(struct vti_net *ipn, struct ip_tunnel *t)
189 {
190 	struct ip_tunnel __rcu **tp;
191 	struct ip_tunnel *iter;
192 
193 	for (tp = vti_bucket(ipn, t);
194 	     (iter = rtnl_dereference(*tp)) != NULL;
195 	     tp = &iter->next) {
196 		if (t == iter) {
197 			rcu_assign_pointer(*tp, t->next);
198 			break;
199 		}
200 	}
201 }
202 
203 static void vti_tunnel_link(struct vti_net *ipn, struct ip_tunnel *t)
204 {
205 	struct ip_tunnel __rcu **tp = vti_bucket(ipn, t);
206 
207 	rcu_assign_pointer(t->next, rtnl_dereference(*tp));
208 	rcu_assign_pointer(*tp, t);
209 }
210 
211 static struct ip_tunnel *vti_tunnel_locate(struct net *net,
212 					   struct ip_tunnel_parm *parms,
213 					   int create)
214 {
215 	__be32 remote = parms->iph.daddr;
216 	__be32 local = parms->iph.saddr;
217 	struct ip_tunnel *t, *nt;
218 	struct ip_tunnel __rcu **tp;
219 	struct net_device *dev;
220 	char name[IFNAMSIZ];
221 	struct vti_net *ipn = net_generic(net, vti_net_id);
222 
223 	for (tp = __vti_bucket(ipn, parms);
224 	     (t = rtnl_dereference(*tp)) != NULL;
225 	     tp = &t->next) {
226 		if (local == t->parms.iph.saddr && remote == t->parms.iph.daddr)
227 			return t;
228 	}
229 	if (!create)
230 		return NULL;
231 
232 	if (parms->name[0])
233 		strlcpy(name, parms->name, IFNAMSIZ);
234 	else
235 		strcpy(name, "vti%d");
236 
237 	dev = alloc_netdev(sizeof(*t), name, vti_tunnel_setup);
238 	if (dev == NULL)
239 		return NULL;
240 
241 	dev_net_set(dev, net);
242 
243 	nt = netdev_priv(dev);
244 	nt->parms = *parms;
245 	dev->rtnl_link_ops = &vti_link_ops;
246 
247 	vti_tunnel_bind_dev(dev);
248 
249 	if (register_netdevice(dev) < 0)
250 		goto failed_free;
251 
252 	dev_hold(dev);
253 	vti_tunnel_link(ipn, nt);
254 	return nt;
255 
256 failed_free:
257 	free_netdev(dev);
258 	return NULL;
259 }
260 
261 static void vti_tunnel_uninit(struct net_device *dev)
262 {
263 	struct net *net = dev_net(dev);
264 	struct vti_net *ipn = net_generic(net, vti_net_id);
265 
266 	vti_tunnel_unlink(ipn, netdev_priv(dev));
267 	dev_put(dev);
268 }
269 
270 static int vti_err(struct sk_buff *skb, u32 info)
271 {
272 
273 	/* All the routers (except for Linux) return only
274 	 * 8 bytes of packet payload. It means, that precise relaying of
275 	 * ICMP in the real Internet is absolutely infeasible.
276 	 */
277 	struct iphdr *iph = (struct iphdr *)skb->data;
278 	const int type = icmp_hdr(skb)->type;
279 	const int code = icmp_hdr(skb)->code;
280 	struct ip_tunnel *t;
281 	int err;
282 
283 	switch (type) {
284 	default:
285 	case ICMP_PARAMETERPROB:
286 		return 0;
287 
288 	case ICMP_DEST_UNREACH:
289 		switch (code) {
290 		case ICMP_SR_FAILED:
291 		case ICMP_PORT_UNREACH:
292 			/* Impossible event. */
293 			return 0;
294 		default:
295 			/* All others are translated to HOST_UNREACH. */
296 			break;
297 		}
298 		break;
299 	case ICMP_TIME_EXCEEDED:
300 		if (code != ICMP_EXC_TTL)
301 			return 0;
302 		break;
303 	}
304 
305 	err = -ENOENT;
306 
307 	t = vti_tunnel_lookup(dev_net(skb->dev), iph->daddr, iph->saddr);
308 	if (t == NULL)
309 		goto out;
310 
311 	if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
312 		ipv4_update_pmtu(skb, dev_net(skb->dev), info,
313 				 t->parms.link, 0, IPPROTO_IPIP, 0);
314 		err = 0;
315 		goto out;
316 	}
317 
318 	err = 0;
319 	if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
320 		goto out;
321 
322 	if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
323 		t->err_count++;
324 	else
325 		t->err_count = 1;
326 	t->err_time = jiffies;
327 out:
328 	return err;
329 }
330 
331 /* We dont digest the packet therefore let the packet pass */
332 static int vti_rcv(struct sk_buff *skb)
333 {
334 	struct ip_tunnel *tunnel;
335 	const struct iphdr *iph = ip_hdr(skb);
336 
337 	tunnel = vti_tunnel_lookup(dev_net(skb->dev), iph->saddr, iph->daddr);
338 	if (tunnel != NULL) {
339 		struct pcpu_tstats *tstats;
340 
341 		tstats = this_cpu_ptr(tunnel->dev->tstats);
342 		u64_stats_update_begin(&tstats->syncp);
343 		tstats->rx_packets++;
344 		tstats->rx_bytes += skb->len;
345 		u64_stats_update_end(&tstats->syncp);
346 
347 		skb->dev = tunnel->dev;
348 		return 1;
349 	}
350 
351 	return -1;
352 }
353 
354 /* This function assumes it is being called from dev_queue_xmit()
355  * and that skb is filled properly by that function.
356  */
357 
358 static netdev_tx_t vti_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
359 {
360 	struct ip_tunnel *tunnel = netdev_priv(dev);
361 	struct pcpu_tstats *tstats;
362 	struct iphdr  *tiph = &tunnel->parms.iph;
363 	u8     tos;
364 	struct rtable *rt;		/* Route to the other host */
365 	struct net_device *tdev;	/* Device to other host */
366 	struct iphdr  *old_iph = ip_hdr(skb);
367 	__be32 dst = tiph->daddr;
368 	struct flowi4 fl4;
369 
370 	if (skb->protocol != htons(ETH_P_IP))
371 		goto tx_error;
372 
373 	tos = old_iph->tos;
374 
375 	memset(&fl4, 0, sizeof(fl4));
376 	flowi4_init_output(&fl4, tunnel->parms.link,
377 			   htonl(tunnel->parms.i_key), RT_TOS(tos),
378 			   RT_SCOPE_UNIVERSE,
379 			   IPPROTO_IPIP, 0,
380 			   dst, tiph->saddr, 0, 0);
381 	rt = ip_route_output_key(dev_net(dev), &fl4);
382 	if (IS_ERR(rt)) {
383 		dev->stats.tx_carrier_errors++;
384 		goto tx_error_icmp;
385 	}
386 	/* if there is no transform then this tunnel is not functional.
387 	 * Or if the xfrm is not mode tunnel.
388 	 */
389 	if (!rt->dst.xfrm ||
390 	    rt->dst.xfrm->props.mode != XFRM_MODE_TUNNEL) {
391 		dev->stats.tx_carrier_errors++;
392 		goto tx_error_icmp;
393 	}
394 	tdev = rt->dst.dev;
395 
396 	if (tdev == dev) {
397 		ip_rt_put(rt);
398 		dev->stats.collisions++;
399 		goto tx_error;
400 	}
401 
402 	if (tunnel->err_count > 0) {
403 		if (time_before(jiffies,
404 				tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
405 			tunnel->err_count--;
406 			dst_link_failure(skb);
407 		} else
408 			tunnel->err_count = 0;
409 	}
410 
411 	IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED |
412 			      IPSKB_REROUTED);
413 	skb_dst_drop(skb);
414 	skb_dst_set(skb, &rt->dst);
415 	nf_reset(skb);
416 	skb->dev = skb_dst(skb)->dev;
417 
418 	tstats = this_cpu_ptr(dev->tstats);
419 	VTI_XMIT(tstats, &dev->stats);
420 	return NETDEV_TX_OK;
421 
422 tx_error_icmp:
423 	dst_link_failure(skb);
424 tx_error:
425 	dev->stats.tx_errors++;
426 	dev_kfree_skb(skb);
427 	return NETDEV_TX_OK;
428 }
429 
430 static int vti_tunnel_bind_dev(struct net_device *dev)
431 {
432 	struct net_device *tdev = NULL;
433 	struct ip_tunnel *tunnel;
434 	struct iphdr *iph;
435 
436 	tunnel = netdev_priv(dev);
437 	iph = &tunnel->parms.iph;
438 
439 	if (iph->daddr) {
440 		struct rtable *rt;
441 		struct flowi4 fl4;
442 		memset(&fl4, 0, sizeof(fl4));
443 		flowi4_init_output(&fl4, tunnel->parms.link,
444 				   htonl(tunnel->parms.i_key),
445 				   RT_TOS(iph->tos), RT_SCOPE_UNIVERSE,
446 				   IPPROTO_IPIP, 0,
447 				   iph->daddr, iph->saddr, 0, 0);
448 		rt = ip_route_output_key(dev_net(dev), &fl4);
449 		if (!IS_ERR(rt)) {
450 			tdev = rt->dst.dev;
451 			ip_rt_put(rt);
452 		}
453 		dev->flags |= IFF_POINTOPOINT;
454 	}
455 
456 	if (!tdev && tunnel->parms.link)
457 		tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link);
458 
459 	if (tdev) {
460 		dev->hard_header_len = tdev->hard_header_len +
461 				       sizeof(struct iphdr);
462 		dev->mtu = tdev->mtu;
463 	}
464 	dev->iflink = tunnel->parms.link;
465 	return dev->mtu;
466 }
467 
468 static int
469 vti_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
470 {
471 	int err = 0;
472 	struct ip_tunnel_parm p;
473 	struct ip_tunnel *t;
474 	struct net *net = dev_net(dev);
475 	struct vti_net *ipn = net_generic(net, vti_net_id);
476 
477 	switch (cmd) {
478 	case SIOCGETTUNNEL:
479 		t = NULL;
480 		if (dev == ipn->fb_tunnel_dev) {
481 			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data,
482 					   sizeof(p))) {
483 				err = -EFAULT;
484 				break;
485 			}
486 			t = vti_tunnel_locate(net, &p, 0);
487 		}
488 		if (t == NULL)
489 			t = netdev_priv(dev);
490 		memcpy(&p, &t->parms, sizeof(p));
491 		p.i_flags |= GRE_KEY | VTI_ISVTI;
492 		p.o_flags |= GRE_KEY;
493 		if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
494 			err = -EFAULT;
495 		break;
496 
497 	case SIOCADDTUNNEL:
498 	case SIOCCHGTUNNEL:
499 		err = -EPERM;
500 		if (!capable(CAP_NET_ADMIN))
501 			goto done;
502 
503 		err = -EFAULT;
504 		if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
505 			goto done;
506 
507 		err = -EINVAL;
508 		if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPIP ||
509 		    p.iph.ihl != 5)
510 			goto done;
511 
512 		t = vti_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
513 
514 		if (dev != ipn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
515 			if (t != NULL) {
516 				if (t->dev != dev) {
517 					err = -EEXIST;
518 					break;
519 				}
520 			} else {
521 				if (((dev->flags&IFF_POINTOPOINT) &&
522 				    !p.iph.daddr) ||
523 				    (!(dev->flags&IFF_POINTOPOINT) &&
524 				    p.iph.daddr)) {
525 					err = -EINVAL;
526 					break;
527 				}
528 				t = netdev_priv(dev);
529 				vti_tunnel_unlink(ipn, t);
530 				synchronize_net();
531 				t->parms.iph.saddr = p.iph.saddr;
532 				t->parms.iph.daddr = p.iph.daddr;
533 				t->parms.i_key = p.i_key;
534 				t->parms.o_key = p.o_key;
535 				t->parms.iph.protocol = IPPROTO_IPIP;
536 				memcpy(dev->dev_addr, &p.iph.saddr, 4);
537 				memcpy(dev->broadcast, &p.iph.daddr, 4);
538 				vti_tunnel_link(ipn, t);
539 				netdev_state_change(dev);
540 			}
541 		}
542 
543 		if (t) {
544 			err = 0;
545 			if (cmd == SIOCCHGTUNNEL) {
546 				t->parms.i_key = p.i_key;
547 				t->parms.o_key = p.o_key;
548 				if (t->parms.link != p.link) {
549 					t->parms.link = p.link;
550 					vti_tunnel_bind_dev(dev);
551 					netdev_state_change(dev);
552 				}
553 			}
554 			p.i_flags |= GRE_KEY | VTI_ISVTI;
555 			p.o_flags |= GRE_KEY;
556 			if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms,
557 					 sizeof(p)))
558 				err = -EFAULT;
559 		} else
560 			err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
561 		break;
562 
563 	case SIOCDELTUNNEL:
564 		err = -EPERM;
565 		if (!capable(CAP_NET_ADMIN))
566 			goto done;
567 
568 		if (dev == ipn->fb_tunnel_dev) {
569 			err = -EFAULT;
570 			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data,
571 					   sizeof(p)))
572 				goto done;
573 			err = -ENOENT;
574 
575 			t = vti_tunnel_locate(net, &p, 0);
576 			if (t == NULL)
577 				goto done;
578 			err = -EPERM;
579 			if (t->dev == ipn->fb_tunnel_dev)
580 				goto done;
581 			dev = t->dev;
582 		}
583 		unregister_netdevice(dev);
584 		err = 0;
585 		break;
586 
587 	default:
588 		err = -EINVAL;
589 	}
590 
591 done:
592 	return err;
593 }
594 
595 static int vti_tunnel_change_mtu(struct net_device *dev, int new_mtu)
596 {
597 	if (new_mtu < 68 || new_mtu > 0xFFF8)
598 		return -EINVAL;
599 	dev->mtu = new_mtu;
600 	return 0;
601 }
602 
603 static const struct net_device_ops vti_netdev_ops = {
604 	.ndo_init	= vti_tunnel_init,
605 	.ndo_uninit	= vti_tunnel_uninit,
606 	.ndo_start_xmit	= vti_tunnel_xmit,
607 	.ndo_do_ioctl	= vti_tunnel_ioctl,
608 	.ndo_change_mtu	= vti_tunnel_change_mtu,
609 	.ndo_get_stats64 = vti_get_stats64,
610 };
611 
612 static void vti_dev_free(struct net_device *dev)
613 {
614 	free_percpu(dev->tstats);
615 	free_netdev(dev);
616 }
617 
618 static void vti_tunnel_setup(struct net_device *dev)
619 {
620 	dev->netdev_ops		= &vti_netdev_ops;
621 	dev->destructor		= vti_dev_free;
622 
623 	dev->type		= ARPHRD_TUNNEL;
624 	dev->hard_header_len	= LL_MAX_HEADER + sizeof(struct iphdr);
625 	dev->mtu		= ETH_DATA_LEN;
626 	dev->flags		= IFF_NOARP;
627 	dev->iflink		= 0;
628 	dev->addr_len		= 4;
629 	dev->features		|= NETIF_F_NETNS_LOCAL;
630 	dev->features		|= NETIF_F_LLTX;
631 	dev->priv_flags		&= ~IFF_XMIT_DST_RELEASE;
632 }
633 
634 static int vti_tunnel_init(struct net_device *dev)
635 {
636 	struct ip_tunnel *tunnel = netdev_priv(dev);
637 
638 	tunnel->dev = dev;
639 	strcpy(tunnel->parms.name, dev->name);
640 
641 	memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
642 	memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
643 
644 	dev->tstats = alloc_percpu(struct pcpu_tstats);
645 	if (!dev->tstats)
646 		return -ENOMEM;
647 
648 	return 0;
649 }
650 
651 static int __net_init vti_fb_tunnel_init(struct net_device *dev)
652 {
653 	struct ip_tunnel *tunnel = netdev_priv(dev);
654 	struct iphdr *iph = &tunnel->parms.iph;
655 	struct vti_net *ipn = net_generic(dev_net(dev), vti_net_id);
656 
657 	tunnel->dev = dev;
658 	strcpy(tunnel->parms.name, dev->name);
659 
660 	iph->version		= 4;
661 	iph->protocol		= IPPROTO_IPIP;
662 	iph->ihl		= 5;
663 
664 	dev->tstats = alloc_percpu(struct pcpu_tstats);
665 	if (!dev->tstats)
666 		return -ENOMEM;
667 
668 	dev_hold(dev);
669 	rcu_assign_pointer(ipn->tunnels_wc[0], tunnel);
670 	return 0;
671 }
672 
673 static struct xfrm_tunnel vti_handler __read_mostly = {
674 	.handler	=	vti_rcv,
675 	.err_handler	=	vti_err,
676 	.priority	=	1,
677 };
678 
679 static void vti_destroy_tunnels(struct vti_net *ipn, struct list_head *head)
680 {
681 	int prio;
682 
683 	for (prio = 1; prio < 4; prio++) {
684 		int h;
685 		for (h = 0; h < HASH_SIZE; h++) {
686 			struct ip_tunnel *t;
687 
688 			t = rtnl_dereference(ipn->tunnels[prio][h]);
689 			while (t != NULL) {
690 				unregister_netdevice_queue(t->dev, head);
691 				t = rtnl_dereference(t->next);
692 			}
693 		}
694 	}
695 }
696 
697 static int __net_init vti_init_net(struct net *net)
698 {
699 	int err;
700 	struct vti_net *ipn = net_generic(net, vti_net_id);
701 
702 	ipn->tunnels[0] = ipn->tunnels_wc;
703 	ipn->tunnels[1] = ipn->tunnels_l;
704 	ipn->tunnels[2] = ipn->tunnels_r;
705 	ipn->tunnels[3] = ipn->tunnels_r_l;
706 
707 	ipn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel),
708 					  "ip_vti0",
709 					  vti_tunnel_setup);
710 	if (!ipn->fb_tunnel_dev) {
711 		err = -ENOMEM;
712 		goto err_alloc_dev;
713 	}
714 	dev_net_set(ipn->fb_tunnel_dev, net);
715 
716 	err = vti_fb_tunnel_init(ipn->fb_tunnel_dev);
717 	if (err)
718 		goto err_reg_dev;
719 	ipn->fb_tunnel_dev->rtnl_link_ops = &vti_link_ops;
720 
721 	err = register_netdev(ipn->fb_tunnel_dev);
722 	if (err)
723 		goto err_reg_dev;
724 	return 0;
725 
726 err_reg_dev:
727 	vti_dev_free(ipn->fb_tunnel_dev);
728 err_alloc_dev:
729 	/* nothing */
730 	return err;
731 }
732 
733 static void __net_exit vti_exit_net(struct net *net)
734 {
735 	struct vti_net *ipn = net_generic(net, vti_net_id);
736 	LIST_HEAD(list);
737 
738 	rtnl_lock();
739 	vti_destroy_tunnels(ipn, &list);
740 	unregister_netdevice_many(&list);
741 	rtnl_unlock();
742 }
743 
744 static struct pernet_operations vti_net_ops = {
745 	.init = vti_init_net,
746 	.exit = vti_exit_net,
747 	.id   = &vti_net_id,
748 	.size = sizeof(struct vti_net),
749 };
750 
751 static int vti_tunnel_validate(struct nlattr *tb[], struct nlattr *data[])
752 {
753 	return 0;
754 }
755 
756 static void vti_netlink_parms(struct nlattr *data[],
757 			      struct ip_tunnel_parm *parms)
758 {
759 	memset(parms, 0, sizeof(*parms));
760 
761 	parms->iph.protocol = IPPROTO_IPIP;
762 
763 	if (!data)
764 		return;
765 
766 	if (data[IFLA_VTI_LINK])
767 		parms->link = nla_get_u32(data[IFLA_VTI_LINK]);
768 
769 	if (data[IFLA_VTI_IKEY])
770 		parms->i_key = nla_get_be32(data[IFLA_VTI_IKEY]);
771 
772 	if (data[IFLA_VTI_OKEY])
773 		parms->o_key = nla_get_be32(data[IFLA_VTI_OKEY]);
774 
775 	if (data[IFLA_VTI_LOCAL])
776 		parms->iph.saddr = nla_get_be32(data[IFLA_VTI_LOCAL]);
777 
778 	if (data[IFLA_VTI_REMOTE])
779 		parms->iph.daddr = nla_get_be32(data[IFLA_VTI_REMOTE]);
780 
781 }
782 
783 static int vti_newlink(struct net *src_net, struct net_device *dev,
784 		       struct nlattr *tb[], struct nlattr *data[])
785 {
786 	struct ip_tunnel *nt;
787 	struct net *net = dev_net(dev);
788 	struct vti_net *ipn = net_generic(net, vti_net_id);
789 	int mtu;
790 	int err;
791 
792 	nt = netdev_priv(dev);
793 	vti_netlink_parms(data, &nt->parms);
794 
795 	if (vti_tunnel_locate(net, &nt->parms, 0))
796 		return -EEXIST;
797 
798 	mtu = vti_tunnel_bind_dev(dev);
799 	if (!tb[IFLA_MTU])
800 		dev->mtu = mtu;
801 
802 	err = register_netdevice(dev);
803 	if (err)
804 		goto out;
805 
806 	dev_hold(dev);
807 	vti_tunnel_link(ipn, nt);
808 
809 out:
810 	return err;
811 }
812 
813 static int vti_changelink(struct net_device *dev, struct nlattr *tb[],
814 			  struct nlattr *data[])
815 {
816 	struct ip_tunnel *t, *nt;
817 	struct net *net = dev_net(dev);
818 	struct vti_net *ipn = net_generic(net, vti_net_id);
819 	struct ip_tunnel_parm p;
820 	int mtu;
821 
822 	if (dev == ipn->fb_tunnel_dev)
823 		return -EINVAL;
824 
825 	nt = netdev_priv(dev);
826 	vti_netlink_parms(data, &p);
827 
828 	t = vti_tunnel_locate(net, &p, 0);
829 
830 	if (t) {
831 		if (t->dev != dev)
832 			return -EEXIST;
833 	} else {
834 		t = nt;
835 
836 		vti_tunnel_unlink(ipn, t);
837 		t->parms.iph.saddr = p.iph.saddr;
838 		t->parms.iph.daddr = p.iph.daddr;
839 		t->parms.i_key = p.i_key;
840 		t->parms.o_key = p.o_key;
841 		if (dev->type != ARPHRD_ETHER) {
842 			memcpy(dev->dev_addr, &p.iph.saddr, 4);
843 			memcpy(dev->broadcast, &p.iph.daddr, 4);
844 		}
845 		vti_tunnel_link(ipn, t);
846 		netdev_state_change(dev);
847 	}
848 
849 	if (t->parms.link != p.link) {
850 		t->parms.link = p.link;
851 		mtu = vti_tunnel_bind_dev(dev);
852 		if (!tb[IFLA_MTU])
853 			dev->mtu = mtu;
854 		netdev_state_change(dev);
855 	}
856 
857 	return 0;
858 }
859 
860 static size_t vti_get_size(const struct net_device *dev)
861 {
862 	return
863 		/* IFLA_VTI_LINK */
864 		nla_total_size(4) +
865 		/* IFLA_VTI_IKEY */
866 		nla_total_size(4) +
867 		/* IFLA_VTI_OKEY */
868 		nla_total_size(4) +
869 		/* IFLA_VTI_LOCAL */
870 		nla_total_size(4) +
871 		/* IFLA_VTI_REMOTE */
872 		nla_total_size(4) +
873 		0;
874 }
875 
876 static int vti_fill_info(struct sk_buff *skb, const struct net_device *dev)
877 {
878 	struct ip_tunnel *t = netdev_priv(dev);
879 	struct ip_tunnel_parm *p = &t->parms;
880 
881 	nla_put_u32(skb, IFLA_VTI_LINK, p->link);
882 	nla_put_be32(skb, IFLA_VTI_IKEY, p->i_key);
883 	nla_put_be32(skb, IFLA_VTI_OKEY, p->o_key);
884 	nla_put_be32(skb, IFLA_VTI_LOCAL, p->iph.saddr);
885 	nla_put_be32(skb, IFLA_VTI_REMOTE, p->iph.daddr);
886 
887 	return 0;
888 }
889 
890 static const struct nla_policy vti_policy[IFLA_VTI_MAX + 1] = {
891 	[IFLA_VTI_LINK]		= { .type = NLA_U32 },
892 	[IFLA_VTI_IKEY]		= { .type = NLA_U32 },
893 	[IFLA_VTI_OKEY]		= { .type = NLA_U32 },
894 	[IFLA_VTI_LOCAL]	= { .len = FIELD_SIZEOF(struct iphdr, saddr) },
895 	[IFLA_VTI_REMOTE]	= { .len = FIELD_SIZEOF(struct iphdr, daddr) },
896 };
897 
898 static struct rtnl_link_ops vti_link_ops __read_mostly = {
899 	.kind		= "vti",
900 	.maxtype	= IFLA_VTI_MAX,
901 	.policy		= vti_policy,
902 	.priv_size	= sizeof(struct ip_tunnel),
903 	.setup		= vti_tunnel_setup,
904 	.validate	= vti_tunnel_validate,
905 	.newlink	= vti_newlink,
906 	.changelink	= vti_changelink,
907 	.get_size	= vti_get_size,
908 	.fill_info	= vti_fill_info,
909 };
910 
911 static int __init vti_init(void)
912 {
913 	int err;
914 
915 	pr_info("IPv4 over IPSec tunneling driver\n");
916 
917 	err = register_pernet_device(&vti_net_ops);
918 	if (err < 0)
919 		return err;
920 	err = xfrm4_mode_tunnel_input_register(&vti_handler);
921 	if (err < 0) {
922 		unregister_pernet_device(&vti_net_ops);
923 		pr_info(KERN_INFO "vti init: can't register tunnel\n");
924 	}
925 
926 	err = rtnl_link_register(&vti_link_ops);
927 	if (err < 0)
928 		goto rtnl_link_failed;
929 
930 	return err;
931 
932 rtnl_link_failed:
933 	xfrm4_mode_tunnel_input_deregister(&vti_handler);
934 	unregister_pernet_device(&vti_net_ops);
935 	return err;
936 }
937 
938 static void __exit vti_fini(void)
939 {
940 	rtnl_link_unregister(&vti_link_ops);
941 	if (xfrm4_mode_tunnel_input_deregister(&vti_handler))
942 		pr_info("vti close: can't deregister tunnel\n");
943 
944 	unregister_pernet_device(&vti_net_ops);
945 }
946 
947 module_init(vti_init);
948 module_exit(vti_fini);
949 MODULE_LICENSE("GPL");
950 MODULE_ALIAS_RTNL_LINK("vti");
951 MODULE_ALIAS_NETDEV("ip_vti0");
952