ip6_vti.c 29.3 KB
Newer Older
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
/*
 *	IPv6 virtual tunneling interface
 *
 *	Copyright (C) 2013 secunet Security Networks AG
 *
 *	Author:
 *	Steffen Klassert <steffen.klassert@secunet.com>
 *
 *	Based on:
 *	net/ipv6/ip6_tunnel.c
 *
 *	This program is free software; you can redistribute it and/or
 *	modify it under the terms of the GNU General Public License
 *	as published by the Free Software Foundation; either version
 *	2 of the License, or (at your option) any later version.
 */

#include <linux/module.h>
#include <linux/capability.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/sockios.h>
#include <linux/icmp.h>
#include <linux/if.h>
#include <linux/in.h>
#include <linux/ip.h>
#include <linux/net.h>
#include <linux/in6.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <linux/icmpv6.h>
#include <linux/init.h>
#include <linux/route.h>
#include <linux/rtnetlink.h>
#include <linux/netfilter_ipv6.h>
#include <linux/slab.h>
#include <linux/hash.h>

#include <linux/uaccess.h>
#include <linux/atomic.h>

#include <net/icmp.h>
#include <net/ip.h>
#include <net/ip_tunnels.h>
#include <net/ipv6.h>
#include <net/ip6_route.h>
#include <net/addrconf.h>
#include <net/ip6_tunnel.h>
#include <net/xfrm.h>
#include <net/net_namespace.h>
#include <net/netns/generic.h>
52
#include <linux/etherdevice.h>
53

54
55
#define IP6_VTI_HASH_SIZE_SHIFT  5
#define IP6_VTI_HASH_SIZE (1 << IP6_VTI_HASH_SIZE_SHIFT)
56
57
58
59
60

static u32 HASH(const struct in6_addr *addr1, const struct in6_addr *addr2)
{
	u32 hash = ipv6_addr_hash(addr1) ^ ipv6_addr_hash(addr2);

61
	return hash_32(hash, IP6_VTI_HASH_SIZE_SHIFT);
62
63
64
65
66
67
}

static int vti6_dev_init(struct net_device *dev);
static void vti6_dev_setup(struct net_device *dev);
static struct rtnl_link_ops vti6_link_ops __read_mostly;

68
static unsigned int vti6_net_id __read_mostly;
69
70
71
72
struct vti6_net {
	/* the vti6 tunnel fallback device */
	struct net_device *fb_tnl_dev;
	/* lists for storing tunnels in use */
73
	struct ip6_tnl __rcu *tnls_r_l[IP6_VTI_HASH_SIZE];
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
	struct ip6_tnl __rcu *tnls_wc[1];
	struct ip6_tnl __rcu **tnls[2];
};

#define for_each_vti6_tunnel_rcu(start) \
	for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))

/**
 * vti6_tnl_lookup - fetch tunnel matching the end-point addresses
 *   @net: network namespace
 *   @remote: the address of the tunnel exit-point
 *   @local: the address of the tunnel entry-point
 *
 * Return:
 *   tunnel matching given end-points if found,
 *   else fallback tunnel if its device is up,
 *   else %NULL
 **/
static struct ip6_tnl *
vti6_tnl_lookup(struct net *net, const struct in6_addr *remote,
		const struct in6_addr *local)
{
	unsigned int hash = HASH(remote, local);
	struct ip6_tnl *t;
	struct vti6_net *ip6n = net_generic(net, vti6_net_id);
99
	struct in6_addr any;
100
101
102
103
104
105
106

	for_each_vti6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
		if (ipv6_addr_equal(local, &t->parms.laddr) &&
		    ipv6_addr_equal(remote, &t->parms.raddr) &&
		    (t->dev->flags & IFF_UP))
			return t;
	}
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122

	memset(&any, 0, sizeof(any));
	hash = HASH(&any, local);
	for_each_vti6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
		if (ipv6_addr_equal(local, &t->parms.laddr) &&
		    (t->dev->flags & IFF_UP))
			return t;
	}

	hash = HASH(remote, &any);
	for_each_vti6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
		if (ipv6_addr_equal(remote, &t->parms.raddr) &&
		    (t->dev->flags & IFF_UP))
			return t;
	}

123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
	t = rcu_dereference(ip6n->tnls_wc[0]);
	if (t && (t->dev->flags & IFF_UP))
		return t;

	return NULL;
}

/**
 * vti6_tnl_bucket - get head of list matching given tunnel parameters
 *   @p: parameters containing tunnel end-points
 *
 * Description:
 *   vti6_tnl_bucket() returns the head of the list matching the
 *   &struct in6_addr entries laddr and raddr in @p.
 *
 * Return: head of IPv6 tunnel list
 **/
static struct ip6_tnl __rcu **
vti6_tnl_bucket(struct vti6_net *ip6n, const struct __ip6_tnl_parm *p)
{
	const struct in6_addr *remote = &p->raddr;
	const struct in6_addr *local = &p->laddr;
	unsigned int h = 0;
	int prio = 0;

	if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) {
		prio = 1;
		h = HASH(remote, local);
	}
	return &ip6n->tnls[prio][h];
}

static void
vti6_tnl_link(struct vti6_net *ip6n, struct ip6_tnl *t)
{
	struct ip6_tnl __rcu **tp = vti6_tnl_bucket(ip6n, &t->parms);

	rcu_assign_pointer(t->next , rtnl_dereference(*tp));
	rcu_assign_pointer(*tp, t);
}

static void
vti6_tnl_unlink(struct vti6_net *ip6n, struct ip6_tnl *t)
{
	struct ip6_tnl __rcu **tp;
	struct ip6_tnl *iter;

	for (tp = vti6_tnl_bucket(ip6n, &t->parms);
	     (iter = rtnl_dereference(*tp)) != NULL;
	     tp = &iter->next) {
		if (t == iter) {
			rcu_assign_pointer(*tp, t->next);
			break;
		}
	}
}

static void vti6_dev_free(struct net_device *dev)
{
	free_percpu(dev->tstats);
}

static int vti6_tnl_create2(struct net_device *dev)
{
	struct ip6_tnl *t = netdev_priv(dev);
	struct net *net = dev_net(dev);
	struct vti6_net *ip6n = net_generic(net, vti6_net_id);
	int err;

192
	dev->rtnl_link_ops = &vti6_link_ops;
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
	err = register_netdevice(dev);
	if (err < 0)
		goto out;

	strcpy(t->parms.name, dev->name);

	dev_hold(dev);
	vti6_tnl_link(ip6n, t);

	return 0;

out:
	return err;
}

static struct ip6_tnl *vti6_tnl_create(struct net *net, struct __ip6_tnl_parm *p)
{
	struct net_device *dev;
	struct ip6_tnl *t;
	char name[IFNAMSIZ];
	int err;

215
216
217
	if (p->name[0]) {
		if (!dev_valid_name(p->name))
			goto failed;
218
		strlcpy(name, p->name, IFNAMSIZ);
219
	} else {
220
		sprintf(name, "ip6_vti%%d");
221
	}
222

223
	dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN, vti6_dev_setup);
224
	if (!dev)
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
		goto failed;

	dev_net_set(dev, net);

	t = netdev_priv(dev);
	t->parms = *p;
	t->net = dev_net(dev);

	err = vti6_tnl_create2(dev);
	if (err < 0)
		goto failed_free;

	return t;

failed_free:
240
	free_netdev(dev);
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
failed:
	return NULL;
}

/**
 * vti6_locate - find or create tunnel matching given parameters
 *   @net: network namespace
 *   @p: tunnel parameters
 *   @create: != 0 if allowed to create new tunnel if no match found
 *
 * Description:
 *   vti6_locate() first tries to locate an existing tunnel
 *   based on @parms. If this is unsuccessful, but @create is set a new
 *   tunnel device is created and registered for use.
 *
 * Return:
 *   matching tunnel or NULL
 **/
static struct ip6_tnl *vti6_locate(struct net *net, struct __ip6_tnl_parm *p,
				   int create)
{
	const struct in6_addr *remote = &p->raddr;
	const struct in6_addr *local = &p->laddr;
	struct ip6_tnl __rcu **tp;
	struct ip6_tnl *t;
	struct vti6_net *ip6n = net_generic(net, vti6_net_id);

	for (tp = vti6_tnl_bucket(ip6n, p);
	     (t = rtnl_dereference(*tp)) != NULL;
	     tp = &t->next) {
		if (ipv6_addr_equal(local, &t->parms.laddr) &&
272
273
274
275
		    ipv6_addr_equal(remote, &t->parms.raddr)) {
			if (create)
				return NULL;

276
			return t;
277
		}
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
	}
	if (!create)
		return NULL;
	return vti6_tnl_create(net, p);
}

/**
 * vti6_dev_uninit - tunnel device uninitializer
 *   @dev: the device to be destroyed
 *
 * Description:
 *   vti6_dev_uninit() removes tunnel from its list
 **/
static void vti6_dev_uninit(struct net_device *dev)
{
	struct ip6_tnl *t = netdev_priv(dev);
294
	struct vti6_net *ip6n = net_generic(t->net, vti6_net_id);
295
296
297
298
299
300
301
302
303
304
305
306
307
308

	if (dev == ip6n->fb_tnl_dev)
		RCU_INIT_POINTER(ip6n->tnls_wc[0], NULL);
	else
		vti6_tnl_unlink(ip6n, t);
	dev_put(dev);
}

static int vti6_rcv(struct sk_buff *skb)
{
	struct ip6_tnl *t;
	const struct ipv6hdr *ipv6h = ipv6_hdr(skb);

	rcu_read_lock();
309
	t = vti6_tnl_lookup(dev_net(skb->dev), &ipv6h->saddr, &ipv6h->daddr);
310
	if (t) {
311
312
313
314
315
316
317
318
319
320
		if (t->parms.proto != IPPROTO_IPV6 && t->parms.proto != 0) {
			rcu_read_unlock();
			goto discard;
		}

		if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
			rcu_read_unlock();
			return 0;
		}

321
		ipv6h = ipv6_hdr(skb);
322
323
324
325
326
327
328
		if (!ip6_tnl_rcv_ctl(t, &ipv6h->daddr, &ipv6h->saddr)) {
			t->dev->stats.rx_dropped++;
			rcu_read_unlock();
			goto discard;
		}

		rcu_read_unlock();
329

Nicolas Dichtel's avatar
Nicolas Dichtel committed
330
		return xfrm6_rcv_tnl(skb, t);
331
332
	}
	rcu_read_unlock();
333
	return -EINVAL;
334
335
336
337
338
discard:
	kfree_skb(skb);
	return 0;
}

339
340
341
342
343
344
static int vti6_rcv_cb(struct sk_buff *skb, int err)
{
	unsigned short family;
	struct net_device *dev;
	struct pcpu_sw_netstats *tstats;
	struct xfrm_state *x;
345
	struct xfrm_mode *inner_mode;
346
	struct ip6_tnl *t = XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6;
347
348
	u32 orig_mark = skb->mark;
	int ret;
349
350
351
352
353
354
355
356
357
358
359
360
361
362

	if (!t)
		return 1;

	dev = t->dev;

	if (err) {
		dev->stats.rx_errors++;
		dev->stats.rx_dropped++;

		return 0;
	}

	x = xfrm_input_state(skb);
363
364
365
366
367
368
369
370
371
372
373
374
375

	inner_mode = x->inner_mode;

	if (x->sel.family == AF_UNSPEC) {
		inner_mode = xfrm_ip2inner_mode(x, XFRM_MODE_SKB_CB(skb)->protocol);
		if (inner_mode == NULL) {
			XFRM_INC_STATS(dev_net(skb->dev),
				       LINUX_MIB_XFRMINSTATEMODEERROR);
			return -EINVAL;
		}
	}

	family = inner_mode->afinfo->family;
376

377
378
379
380
381
	skb->mark = be32_to_cpu(t->parms.i_key);
	ret = xfrm_policy_check(NULL, XFRM_POLICY_IN, skb, family);
	skb->mark = orig_mark;

	if (!ret)
382
383
384
385
386
387
388
389
390
391
392
393
394
395
		return -EPERM;

	skb_scrub_packet(skb, !net_eq(t->net, dev_net(skb->dev)));
	skb->dev = dev;

	tstats = this_cpu_ptr(dev->tstats);
	u64_stats_update_begin(&tstats->syncp);
	tstats->rx_packets++;
	tstats->rx_bytes += skb->len;
	u64_stats_update_end(&tstats->syncp);

	return 0;
}

396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
/**
 * vti6_addr_conflict - compare packet addresses to tunnel's own
 *   @t: the outgoing tunnel device
 *   @hdr: IPv6 header from the incoming packet
 *
 * Description:
 *   Avoid trivial tunneling loop by checking that tunnel exit-point
 *   doesn't match source of incoming packet.
 *
 * Return:
 *   1 if conflict,
 *   0 else
 **/
static inline bool
vti6_addr_conflict(const struct ip6_tnl *t, const struct ipv6hdr *hdr)
{
	return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
}

415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
static bool vti6_state_check(const struct xfrm_state *x,
			     const struct in6_addr *dst,
			     const struct in6_addr *src)
{
	xfrm_address_t *daddr = (xfrm_address_t *)dst;
	xfrm_address_t *saddr = (xfrm_address_t *)src;

	/* if there is no transform then this tunnel is not functional.
	 * Or if the xfrm is not mode tunnel.
	 */
	if (!x || x->props.mode != XFRM_MODE_TUNNEL ||
	    x->props.family != AF_INET6)
		return false;

	if (ipv6_addr_any(dst))
		return xfrm_addr_equal(saddr, &x->props.saddr, AF_INET6);

	if (!xfrm_state_addr_check(x, daddr, saddr, AF_INET6))
		return false;

	return true;
}

438
439
440
441
/**
 * vti6_xmit - send a packet
 *   @skb: the outgoing socket buffer
 *   @dev: the outgoing tunnel device
442
 *   @fl: the flow informations for the xfrm_lookup
443
 **/
444
445
static int
vti6_xmit(struct sk_buff *skb, struct net_device *dev, struct flowi *fl)
446
447
448
{
	struct ip6_tnl *t = netdev_priv(dev);
	struct net_device_stats *stats = &t->dev->stats;
449
	struct dst_entry *dst = skb_dst(skb);
450
	struct net_device *tdev;
451
	struct xfrm_state *x;
452
	int pkt_len = skb->len;
453
	int err = -1;
454
	int mtu;
455

456
457
	if (!dst)
		goto tx_err_link_failure;
458

459
	dst_hold(dst);
460
	dst = xfrm_lookup(t->net, dst, fl, NULL, 0);
461
462
463
464
	if (IS_ERR(dst)) {
		err = PTR_ERR(dst);
		dst = NULL;
		goto tx_err_link_failure;
465
466
	}

467
468
469
470
471
472
	x = dst->xfrm;
	if (!vti6_state_check(x, &t->parms.raddr, &t->parms.laddr))
		goto tx_err_link_failure;

	if (!ip6_tnl_xmit_ctl(t, (const struct in6_addr *)&x->props.saddr,
			      (const struct in6_addr *)&x->id.daddr))
473
474
475
476
477
478
479
480
481
482
483
		goto tx_err_link_failure;

	tdev = dst->dev;

	if (tdev == dev) {
		stats->collisions++;
		net_warn_ratelimited("%s: Local routing loop detected!\n",
				     t->parms.name);
		goto tx_err_dst_release;
	}

484
	mtu = dst_mtu(dst);
485
	if (skb->len > mtu) {
486
		skb_dst_update_pmtu(skb, mtu);
487

488
489
490
491
		if (skb->protocol == htons(ETH_P_IPV6)) {
			if (mtu < IPV6_MIN_MTU)
				mtu = IPV6_MIN_MTU;

492
			icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
493
		} else {
494
495
			icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
				  htonl(mtu));
496
		}
497

498
499
		err = -EMSGSIZE;
		goto tx_err_dst_release;
500
501
	}

502
503
504
505
	skb_scrub_packet(skb, !net_eq(t->net, dev_net(dev)));
	skb_dst_set(skb, dst);
	skb->dev = skb_dst(skb)->dev;

506
	err = dst_output(t->net, skb->sk, skb);
507
508
509
	if (net_xmit_eval(err) == 0)
		err = pkt_len;
	iptunnel_xmit_stats(dev, err);
510
511
512
513
514
515

	return 0;
tx_err_link_failure:
	stats->tx_carrier_errors++;
	dst_link_failure(skb);
tx_err_dst_release:
516
	dst_release(dst);
517
518
519
520
521
522
523
524
	return err;
}

static netdev_tx_t
vti6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct ip6_tnl *t = netdev_priv(dev);
	struct net_device_stats *stats = &t->dev->stats;
525
	struct flowi fl;
526
527
	int ret;

528
529
530
	if (!pskb_inet_may_pull(skb))
		goto tx_err;

531
532
	memset(&fl, 0, sizeof(fl));

533
534
	switch (skb->protocol) {
	case htons(ETH_P_IPV6):
535
		if ((t->parms.proto != IPPROTO_IPV6 && t->parms.proto != 0) ||
536
		    vti6_addr_conflict(t, ipv6_hdr(skb)))
537
538
539
540
541
542
543
544
			goto tx_err;

		xfrm_decode_session(skb, &fl, AF_INET6);
		memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
		break;
	case htons(ETH_P_IP):
		xfrm_decode_session(skb, &fl, AF_INET);
		memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
545
546
547
548
549
		break;
	default:
		goto tx_err;
	}

550
551
552
	/* override mark with tunnel output key */
	fl.flowi_mark = be32_to_cpu(t->parms.o_key);

553
	ret = vti6_xmit(skb, dev, &fl);
554
555
556
557
558
559
560
561
562
563
564
565
	if (ret < 0)
		goto tx_err;

	return NETDEV_TX_OK;

tx_err:
	stats->tx_errors++;
	stats->tx_dropped++;
	kfree_skb(skb);
	return NETDEV_TX_OK;
}

566
567
568
569
static int vti6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
		    u8 type, u8 code, int offset, __be32 info)
{
	__be32 spi;
570
	__u32 mark;
571
572
573
574
575
576
577
578
579
580
581
582
583
	struct xfrm_state *x;
	struct ip6_tnl *t;
	struct ip_esp_hdr *esph;
	struct ip_auth_hdr *ah;
	struct ip_comp_hdr *ipch;
	struct net *net = dev_net(skb->dev);
	const struct ipv6hdr *iph = (const struct ipv6hdr *)skb->data;
	int protocol = iph->nexthdr;

	t = vti6_tnl_lookup(dev_net(skb->dev), &iph->daddr, &iph->saddr);
	if (!t)
		return -1;

584
585
	mark = be32_to_cpu(t->parms.o_key);

586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
	switch (protocol) {
	case IPPROTO_ESP:
		esph = (struct ip_esp_hdr *)(skb->data + offset);
		spi = esph->spi;
		break;
	case IPPROTO_AH:
		ah = (struct ip_auth_hdr *)(skb->data + offset);
		spi = ah->spi;
		break;
	case IPPROTO_COMP:
		ipch = (struct ip_comp_hdr *)(skb->data + offset);
		spi = htonl(ntohs(ipch->cpi));
		break;
	default:
		return 0;
	}

	if (type != ICMPV6_PKT_TOOBIG &&
	    type != NDISC_REDIRECT)
		return 0;

607
	x = xfrm_state_lookup(net, mark, (const xfrm_address_t *)&iph->daddr,
608
609
610
611
612
			      spi, protocol, AF_INET6);
	if (!x)
		return 0;

	if (type == NDISC_REDIRECT)
613
614
		ip6_redirect(skb, net, skb->dev->ifindex, 0,
			     sock_net_uid(net, NULL));
615
	else
616
		ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL));
617
618
619
620
621
	xfrm_state_put(x);

	return 0;
}

622
static void vti6_link_config(struct ip6_tnl *t, bool keep_mtu)
623
624
625
{
	struct net_device *dev = t->dev;
	struct __ip6_tnl_parm *p = &t->parms;
626
	struct net_device *tdev = NULL;
627
	int mtu;
628
629
630
631
632
633
634
635
636
637
638
639

	memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
	memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));

	p->flags &= ~(IP6_TNL_F_CAP_XMIT | IP6_TNL_F_CAP_RCV |
		      IP6_TNL_F_CAP_PER_PACKET);
	p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);

	if (p->flags & IP6_TNL_F_CAP_XMIT && p->flags & IP6_TNL_F_CAP_RCV)
		dev->flags |= IFF_POINTOPOINT;
	else
		dev->flags &= ~IFF_POINTOPOINT;
640

641
642
643
644
645
	if (keep_mtu && dev->mtu) {
		dev->mtu = clamp(dev->mtu, dev->min_mtu, dev->max_mtu);
		return;
	}

646
647
648
649
650
	if (p->flags & IP6_TNL_F_CAP_XMIT) {
		int strict = (ipv6_addr_type(&p->raddr) &
			      (IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL));
		struct rt6_info *rt = rt6_lookup(t->net,
						 &p->raddr, &p->laddr,
651
						 p->link, NULL, strict);
652
653
654
655
656
657
658
659
660
661

		if (rt)
			tdev = rt->dst.dev;
		ip6_rt_put(rt);
	}

	if (!tdev && p->link)
		tdev = __dev_get_by_index(t->net, p->link);

	if (tdev)
662
663
664
665
		mtu = tdev->mtu - sizeof(struct ipv6hdr);
	else
		mtu = ETH_DATA_LEN - LL_MAX_HEADER - sizeof(struct ipv6hdr);

666
	dev->mtu = max_t(int, mtu, IPV4_MIN_MTU);
667
668
669
670
671
672
}

/**
 * vti6_tnl_change - update the tunnel parameters
 *   @t: tunnel to be changed
 *   @p: tunnel configuration parameters
673
 *   @keep_mtu: MTU was set from userspace, don't re-compute it
674
675
676
677
678
 *
 * Description:
 *   vti6_tnl_change() updates the tunnel parameters
 **/
static int
679
680
vti6_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p,
		bool keep_mtu)
681
682
683
684
685
686
687
{
	t->parms.laddr = p->laddr;
	t->parms.raddr = p->raddr;
	t->parms.link = p->link;
	t->parms.i_key = p->i_key;
	t->parms.o_key = p->o_key;
	t->parms.proto = p->proto;
688
	t->parms.fwmark = p->fwmark;
689
	dst_cache_reset(&t->dst_cache);
690
	vti6_link_config(t, keep_mtu);
691
692
693
	return 0;
}

694
695
static int vti6_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p,
		       bool keep_mtu)
696
697
698
699
700
701
702
{
	struct net *net = dev_net(t->dev);
	struct vti6_net *ip6n = net_generic(net, vti6_net_id);
	int err;

	vti6_tnl_unlink(ip6n, t);
	synchronize_net();
703
	err = vti6_tnl_change(t, p, keep_mtu);
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
	vti6_tnl_link(ip6n, t);
	netdev_state_change(t->dev);
	return err;
}

static void
vti6_parm_from_user(struct __ip6_tnl_parm *p, const struct ip6_tnl_parm2 *u)
{
	p->laddr = u->laddr;
	p->raddr = u->raddr;
	p->link = u->link;
	p->i_key = u->i_key;
	p->o_key = u->o_key;
	p->proto = u->proto;

	memcpy(p->name, u->name, sizeof(u->name));
}

static void
vti6_parm_to_user(struct ip6_tnl_parm2 *u, const struct __ip6_tnl_parm *p)
{
	u->laddr = p->laddr;
	u->raddr = p->raddr;
	u->link = p->link;
	u->i_key = p->i_key;
	u->o_key = p->o_key;
David Forster's avatar
David Forster committed
730
731
732
733
	if (u->i_key)
		u->i_flags |= GRE_KEY;
	if (u->o_key)
		u->o_flags |= GRE_KEY;
734
735
736
737
738
739
	u->proto = p->proto;

	memcpy(u->name, p->name, sizeof(u->name));
}

/**
Sun Lianwen's avatar
Sun Lianwen committed
740
 * vti6_ioctl - configure vti6 tunnels from userspace
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
 *   @dev: virtual device associated with tunnel
 *   @ifr: parameters passed from userspace
 *   @cmd: command to be performed
 *
 * Description:
 *   vti6_ioctl() is used for managing vti6 tunnels
 *   from userspace.
 *
 *   The possible commands are the following:
 *     %SIOCGETTUNNEL: get tunnel parameters for device
 *     %SIOCADDTUNNEL: add tunnel matching given tunnel parameters
 *     %SIOCCHGTUNNEL: change tunnel parameters to those given
 *     %SIOCDELTUNNEL: delete tunnel
 *
 *   The fallback device "ip6_vti0", created during module
 *   initialization, can be used for creating other tunnel devices.
 *
 * Return:
 *   0 on success,
 *   %-EFAULT if unable to copy data to or from userspace,
 *   %-EPERM if current process hasn't %CAP_NET_ADMIN set
 *   %-EINVAL if passed tunnel parameters are invalid,
 *   %-EEXIST if changing a tunnel's parameters would cause a conflict
 *   %-ENODEV if attempting to change or delete a nonexisting device
 **/
static int
vti6_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
{
	int err = 0;
	struct ip6_tnl_parm2 p;
	struct __ip6_tnl_parm p1;
	struct ip6_tnl *t = NULL;
	struct net *net = dev_net(dev);
	struct vti6_net *ip6n = net_generic(net, vti6_net_id);

	switch (cmd) {
	case SIOCGETTUNNEL:
		if (dev == ip6n->fb_tnl_dev) {
			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
				err = -EFAULT;
				break;
			}
			vti6_parm_from_user(&p1, &p);
			t = vti6_locate(net, &p1, 0);
		} else {
			memset(&p, 0, sizeof(p));
		}
788
		if (!t)
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
			t = netdev_priv(dev);
		vti6_parm_to_user(&p, &t->parms);
		if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
			err = -EFAULT;
		break;
	case SIOCADDTUNNEL:
	case SIOCCHGTUNNEL:
		err = -EPERM;
		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
			break;
		err = -EFAULT;
		if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
			break;
		err = -EINVAL;
		if (p.proto != IPPROTO_IPV6  && p.proto != 0)
			break;
		vti6_parm_from_user(&p1, &p);
		t = vti6_locate(net, &p1, cmd == SIOCADDTUNNEL);
		if (dev != ip6n->fb_tnl_dev && cmd == SIOCCHGTUNNEL) {
808
			if (t) {
809
810
811
812
813
814
815
				if (t->dev != dev) {
					err = -EEXIST;
					break;
				}
			} else
				t = netdev_priv(dev);

816
			err = vti6_update(t, &p1, false);
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
		}
		if (t) {
			err = 0;
			vti6_parm_to_user(&p, &t->parms);
			if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
				err = -EFAULT;

		} else
			err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
		break;
	case SIOCDELTUNNEL:
		err = -EPERM;
		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
			break;

		if (dev == ip6n->fb_tnl_dev) {
			err = -EFAULT;
			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
				break;
			err = -ENOENT;
			vti6_parm_from_user(&p1, &p);
			t = vti6_locate(net, &p1, 0);
839
			if (!t)
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
				break;
			err = -EPERM;
			if (t->dev == ip6n->fb_tnl_dev)
				break;
			dev = t->dev;
		}
		err = 0;
		unregister_netdevice(dev);
		break;
	default:
		err = -EINVAL;
	}
	return err;
}

static const struct net_device_ops vti6_netdev_ops = {
856
	.ndo_init	= vti6_dev_init,
857
858
859
	.ndo_uninit	= vti6_dev_uninit,
	.ndo_start_xmit = vti6_tnl_xmit,
	.ndo_do_ioctl	= vti6_ioctl,
860
	.ndo_get_stats64 = ip_tunnel_get_stats64,
861
	.ndo_get_iflink = ip6_tnl_get_iflink,
862
863
864
865
866
867
868
869
870
871
872
873
};

/**
 * vti6_dev_setup - setup virtual tunnel device
 *   @dev: virtual device associated with tunnel
 *
 * Description:
 *   Initialize function pointers and device parameters
 **/
static void vti6_dev_setup(struct net_device *dev)
{
	dev->netdev_ops = &vti6_netdev_ops;
874
875
	dev->needs_free_netdev = true;
	dev->priv_destructor = vti6_dev_free;
876
877

	dev->type = ARPHRD_TUNNEL6;
878
	dev->min_mtu = IPV4_MIN_MTU;
879
	dev->max_mtu = IP_MAX_MTU - sizeof(struct ipv6hdr);
880
881
	dev->flags |= IFF_NOARP;
	dev->addr_len = sizeof(struct in6_addr);
882
	netif_keep_dst(dev);
883
884
885
	/* This perm addr will be used as interface identifier by IPv6 */
	dev->addr_assign_type = NET_ADDR_RANDOM;
	eth_random_addr(dev->perm_addr);
886
887
888
889
890
891
892
893
894
895
896
897
}

/**
 * vti6_dev_init_gen - general initializer for all tunnel devices
 *   @dev: virtual device associated with tunnel
 **/
static inline int vti6_dev_init_gen(struct net_device *dev)
{
	struct ip6_tnl *t = netdev_priv(dev);

	t->dev = dev;
	t->net = dev_net(dev);
898
	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
	if (!dev->tstats)
		return -ENOMEM;
	return 0;
}

/**
 * vti6_dev_init - initializer for all non fallback tunnel devices
 *   @dev: virtual device associated with tunnel
 **/
static int vti6_dev_init(struct net_device *dev)
{
	struct ip6_tnl *t = netdev_priv(dev);
	int err = vti6_dev_init_gen(dev);

	if (err)
		return err;
915
	vti6_link_config(t, true);
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
	return 0;
}

/**
 * vti6_fb_tnl_dev_init - initializer for fallback tunnel device
 *   @dev: fallback device
 *
 * Return: 0
 **/
static int __net_init vti6_fb_tnl_dev_init(struct net_device *dev)
{
	struct ip6_tnl *t = netdev_priv(dev);
	struct net *net = dev_net(dev);
	struct vti6_net *ip6n = net_generic(net, vti6_net_id);

	t->parms.proto = IPPROTO_IPV6;
	dev_hold(dev);

	rcu_assign_pointer(ip6n->tnls_wc[0], t);
	return 0;
}

938
939
static int vti6_validate(struct nlattr *tb[], struct nlattr *data[],
			 struct netlink_ext_ack *extack)
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
{
	return 0;
}

static void vti6_netlink_parms(struct nlattr *data[],
			       struct __ip6_tnl_parm *parms)
{
	memset(parms, 0, sizeof(*parms));

	if (!data)
		return;

	if (data[IFLA_VTI_LINK])
		parms->link = nla_get_u32(data[IFLA_VTI_LINK]);

	if (data[IFLA_VTI_LOCAL])
956
		parms->laddr = nla_get_in6_addr(data[IFLA_VTI_LOCAL]);
957
958

	if (data[IFLA_VTI_REMOTE])
959
		parms->raddr = nla_get_in6_addr(data[IFLA_VTI_REMOTE]);
960
961
962
963
964
965

	if (data[IFLA_VTI_IKEY])
		parms->i_key = nla_get_be32(data[IFLA_VTI_IKEY]);

	if (data[IFLA_VTI_OKEY])
		parms->o_key = nla_get_be32(data[IFLA_VTI_OKEY]);
966
967
968

	if (data[IFLA_VTI_FWMARK])
		parms->fwmark = nla_get_u32(data[IFLA_VTI_FWMARK]);
969
970
971
}

static int vti6_newlink(struct net *src_net, struct net_device *dev,
972
973
			struct nlattr *tb[], struct nlattr *data[],
			struct netlink_ext_ack *extack)
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
{
	struct net *net = dev_net(dev);
	struct ip6_tnl *nt;

	nt = netdev_priv(dev);
	vti6_netlink_parms(data, &nt->parms);

	nt->parms.proto = IPPROTO_IPV6;

	if (vti6_locate(net, &nt->parms, 0))
		return -EEXIST;

	return vti6_tnl_create2(dev);
}

989
990
991
992
993
994
995
996
997
static void vti6_dellink(struct net_device *dev, struct list_head *head)
{
	struct net *net = dev_net(dev);
	struct vti6_net *ip6n = net_generic(net, vti6_net_id);

	if (dev != ip6n->fb_tnl_dev)
		unregister_netdevice_queue(dev, head);
}

998
static int vti6_changelink(struct net_device *dev, struct nlattr *tb[],
999
1000
			   struct nlattr *data[],
			   struct netlink_ext_ack *extack)
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
{
	struct ip6_tnl *t;
	struct __ip6_tnl_parm p;
	struct net *net = dev_net(dev);
	struct vti6_net *ip6n = net_generic(net, vti6_net_id);

	if (dev == ip6n->fb_tnl_dev)
		return -EINVAL;

	vti6_netlink_parms(data, &p);

	t = vti6_locate(net, &p, 0);

	if (t) {
		if (t->dev != dev)
			return -EEXIST;
	} else
		t = netdev_priv(dev);

1020
	return vti6_update(t, &p, tb && tb[IFLA_MTU]);
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
}

static size_t vti6_get_size(const struct net_device *dev)
{
	return
		/* IFLA_VTI_LINK */
		nla_total_size(4) +
		/* IFLA_VTI_LOCAL */
		nla_total_size(sizeof(struct in6_addr)) +
		/* IFLA_VTI_REMOTE */
		nla_total_size(sizeof(struct in6_addr)) +
		/* IFLA_VTI_IKEY */
		nla_total_size(4) +
		/* IFLA_VTI_OKEY */
		nla_total_size(4) +
1036
1037
		/* IFLA_VTI_FWMARK */
		nla_total_size(4) +
1038
1039
1040
1041
1042
1043
1044
1045
1046
		0;
}

static int vti6_fill_info(struct sk_buff *skb, const struct net_device *dev)
{
	struct ip6_tnl *tunnel = netdev_priv(dev);
	struct __ip6_tnl_parm *parm = &tunnel->parms;

	if (nla_put_u32(skb, IFLA_VTI_LINK, parm->link) ||
1047
1048
	    nla_put_in6_addr(skb, IFLA_VTI_LOCAL, &parm->laddr) ||
	    nla_put_in6_addr(skb, IFLA_VTI_REMOTE, &parm->raddr) ||
1049
	    nla_put_be32(skb, IFLA_VTI_IKEY, parm->i_key) ||
1050
1051
	    nla_put_be32(skb, IFLA_VTI_OKEY, parm->o_key) ||
	    nla_put_u32(skb, IFLA_VTI_FWMARK, parm->fwmark))
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
		goto nla_put_failure;
	return 0;

nla_put_failure:
	return -EMSGSIZE;
}

static const struct nla_policy vti6_policy[IFLA_VTI_MAX + 1] = {
	[IFLA_VTI_LINK]		= { .type = NLA_U32 },
	[IFLA_VTI_LOCAL]	= { .len = sizeof(struct in6_addr) },
	[IFLA_VTI_REMOTE]	= { .len = sizeof(struct in6_addr) },
	[IFLA_VTI_IKEY]		= { .type = NLA_U32 },
	[IFLA_VTI_OKEY]		= { .type = NLA_U32 },
1065
	[IFLA_VTI_FWMARK]	= { .type = NLA_U32 },
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
};

static struct rtnl_link_ops vti6_link_ops __read_mostly = {
	.kind		= "vti6",
	.maxtype	= IFLA_VTI_MAX,
	.policy		= vti6_policy,
	.priv_size	= sizeof(struct ip6_tnl),
	.setup		= vti6_dev_setup,
	.validate	= vti6_validate,
	.newlink	= vti6_newlink,
1076
	.dellink	= vti6_dellink,
1077
1078
1079
	.changelink	= vti6_changelink,
	.get_size	= vti6_get_size,
	.fill_info	= vti6_fill_info,
1080
	.get_link_net	= ip6_tnl_get_link_net,
1081
1082
};

1083
1084
static void __net_exit vti6_destroy_tunnels(struct vti6_net *ip6n,
					    struct list_head *list)
1085
1086
1087
1088
{
	int h;
	struct ip6_tnl *t;

1089
	for (h = 0; h < IP6_VTI_HASH_SIZE; h++) {
1090
		t = rtnl_dereference(ip6n->tnls_r_l[h]);
1091
		while (t) {
1092
			unregister_netdevice_queue(t->dev, list);
1093
1094
1095
1096
1097
			t = rtnl_dereference(t->next);
		}
	}

	t = rtnl_dereference(ip6n->tnls_wc[0]);
1098
1099
	if (t)
		unregister_netdevice_queue(t->dev, list);
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
}

static int __net_init vti6_init_net(struct net *net)
{
	struct vti6_net *ip6n = net_generic(net, vti6_net_id);
	struct ip6_tnl *t = NULL;
	int err;

	ip6n->tnls[0] = ip6n->tnls_wc;
	ip6n->tnls[1] = ip6n->tnls_r_l;

1111
1112
	if (!net_has_fallback_tunnels(net))
		return 0;
1113
1114
	err = -ENOMEM;
	ip6n->fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6_vti0",
1115
					NET_NAME_UNKNOWN, vti6_dev_setup);
1116
1117
1118
1119

	if (!ip6n->fb_tnl_dev)
		goto err_alloc_dev;
	dev_net_set(ip6n->fb_tnl_dev, net);
1120
	ip6n->fb_tnl_dev->rtnl_link_ops = &vti6_link_ops;
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135

	err = vti6_fb_tnl_dev_init(ip6n->fb_tnl_dev);
	if (err < 0)
		goto err_register;

	err = register_netdev(ip6n->fb_tnl_dev);
	if (err < 0)
		goto err_register;

	t = netdev_priv(ip6n->fb_tnl_dev);

	strcpy(t->parms.name, ip6n->fb_tnl_dev->name);
	return 0;

err_register:
1136
	free_netdev(ip6n->fb_tnl_dev);
1137
1138
1139
1140
err_alloc_dev:
	return err;
}

1141
static void __net_exit vti6_exit_batch_net(struct list_head *net_list)
1142
{
1143
1144
1145
	struct vti6_net *ip6n;
	struct net *net;
	LIST_HEAD(list);
1146
1147

	rtnl_lock();
1148
1149
1150
1151
1152
	list_for_each_entry(net, net_list, exit_list) {
		ip6n = net_generic(net, vti6_net_id);
		vti6_destroy_tunnels(ip6n, &list);
	}
	unregister_netdevice_many(&list);
1153
1154
1155
1156
1157
	rtnl_unlock();
}

static struct pernet_operations vti6_net_ops = {
	.init = vti6_init_net,
1158
	.exit_batch = vti6_exit_batch_net,
1159
1160
1161
1162
	.id   = &vti6_net_id,
	.size = sizeof(struct vti6_net),
};

1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
static struct xfrm6_protocol vti_esp6_protocol __read_mostly = {
	.handler	=	vti6_rcv,
	.cb_handler	=	vti6_rcv_cb,
	.err_handler	=	vti6_err,
	.priority	=	100,
};

static struct xfrm6_protocol vti_ah6_protocol __read_mostly = {
	.handler	=	vti6_rcv,
	.cb_handler	=	vti6_rcv_cb,
	.err_handler	=	vti6_err,
	.priority	=	100,
};

static struct xfrm6_protocol vti_ipcomp6_protocol __read_mostly = {
	.handler	=	vti6_rcv,
	.cb_handler	=	vti6_rcv_cb,
	.err_handler	=	vti6_err,
	.priority	=	100,
};

1184
1185
1186
1187
1188
1189
1190
/**
 * vti6_tunnel_init - register protocol and reserve needed resources
 *
 * Return: 0 on success
 **/
static int __init vti6_tunnel_init(void)
{
1191
1192
	const char *msg;
	int err;
1193

1194
	msg = "tunnel device";
1195
1196
	err = register_pernet_device(&vti6_net_ops);
	if (err < 0)
1197
		goto pernet_dev_failed;
1198

1199
	msg = "tunnel protocols";
1200
	err = xfrm6_protocol_register(&vti_esp6_protocol, IPPROTO_ESP);
1201
1202
	if (err < 0)
		goto xfrm_proto_esp_failed;
1203
	err = xfrm6_protocol_register(&vti_ah6_protocol, IPPROTO_AH);
1204
1205
	if (err < 0)
		goto xfrm_proto_ah_failed;
1206
	err = xfrm6_protocol_register(&vti_ipcomp6_protocol, IPPROTO_COMP);
1207
1208
	if (err < 0)
		goto xfrm_proto_comp_failed;
1209

1210
	msg = "netlink interface";
1211
1212
1213
1214
1215
1216
1217
	err = rtnl_link_register(&vti6_link_ops);
	if (err < 0)
		goto rtnl_link_failed;

	return 0;

rtnl_link_failed:
1218
	xfrm6_protocol_deregister(&vti_ipcomp6_protocol, IPPROTO_COMP);
1219
xfrm_proto_comp_failed:
1220
	xfrm6_protocol_deregister(&vti_ah6_protocol, IPPROTO_AH);
1221
xfrm_proto_ah_failed:
1222
	xfrm6_protocol_deregister(&vti_esp6_protocol, IPPROTO_ESP);
1223
xfrm_proto_esp_failed:
1224
	unregister_pernet_device(&vti6_net_ops);
1225
1226
pernet_dev_failed:
	pr_err("vti6 init: failed to register %s\n", msg);
1227
1228
1229
1230
1231
1232
1233
1234
1235
	return err;
}

/**
 * vti6_tunnel_cleanup - free resources and unregister protocol
 **/
static void __exit vti6_tunnel_cleanup(void)
{
	rtnl_link_unregister(&vti6_link_ops);
1236
1237
1238
	xfrm6_protocol_deregister(&vti_ipcomp6_protocol, IPPROTO_COMP);
	xfrm6_protocol_deregister(&vti_ah6_protocol, IPPROTO_AH);
	xfrm6_protocol_deregister(&vti_esp6_protocol, IPPROTO_ESP);
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
	unregister_pernet_device(&vti6_net_ops);
}

module_init(vti6_tunnel_init);
module_exit(vti6_tunnel_cleanup);
MODULE_LICENSE("GPL");
MODULE_ALIAS_RTNL_LINK("vti6");
MODULE_ALIAS_NETDEV("ip6_vti0");
MODULE_AUTHOR("Steffen Klassert");
MODULE_DESCRIPTION("IPv6 virtual tunnel interface");