summaryrefslogtreecommitdiff
path: root/net/ipv6/xfrm6_tunnel.c
blob: bf140ef781c1f29db655ea75f44214cbd3da1826 (plain)
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
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
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
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
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
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
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
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C)2003,2004 USAGI/WIDE Project
 *
 * Authors	Mitsuru KANDA  <mk@linux-ipv6.org>
 *		YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
 *
 * Based on net/ipv4/xfrm4_tunnel.c
 */
#include <linux/module.h>
#include <linux/xfrm.h>
#include <linux/slab.h>
#include <linux/rculist.h>
#include <net/ip.h>
#include <net/xfrm.h>
#include <net/ipv6.h>
#include <linux/ipv6.h>
#include <linux/icmpv6.h>
#include <linux/mutex.h>
#include <net/netns/generic.h>

#define XFRM6_TUNNEL_SPI_BYADDR_HSIZE 256
#define XFRM6_TUNNEL_SPI_BYSPI_HSIZE 256

#define XFRM6_TUNNEL_SPI_MIN	1
#define XFRM6_TUNNEL_SPI_MAX	0xffffffff

struct xfrm6_tunnel_net {
	struct hlist_head spi_byaddr[XFRM6_TUNNEL_SPI_BYADDR_HSIZE];
	struct hlist_head spi_byspi[XFRM6_TUNNEL_SPI_BYSPI_HSIZE];
	u32 spi;
};

static unsigned int xfrm6_tunnel_net_id __read_mostly;
static inline struct xfrm6_tunnel_net *xfrm6_tunnel_pernet(struct net *net)
{
	return net_generic(net, xfrm6_tunnel_net_id);
}

/*
 * xfrm_tunnel_spi things are for allocating unique id ("spi")
 * per xfrm_address_t.
 */
struct xfrm6_tunnel_spi {
	struct hlist_node	list_byaddr;
	struct hlist_node	list_byspi;
	xfrm_address_t		addr;
	u32			spi;
	refcount_t		refcnt;
	struct rcu_head		rcu_head;
};

static DEFINE_SPINLOCK(xfrm6_tunnel_spi_lock);

static struct kmem_cache *xfrm6_tunnel_spi_kmem __read_mostly;

static inline unsigned int xfrm6_tunnel_spi_hash_byaddr(const xfrm_address_t *addr)
{
	unsigned int h;

	h = ipv6_addr_hash((const struct in6_addr *)addr);
	h ^= h >> 16;
	h ^= h >> 8;
	h &= XFRM6_TUNNEL_SPI_BYADDR_HSIZE - 1;

	return h;
}

static inline unsigned int xfrm6_tunnel_spi_hash_byspi(u32 spi)
{
	return spi % XFRM6_TUNNEL_SPI_BYSPI_HSIZE;
}

static struct xfrm6_tunnel_spi *__xfrm6_tunnel_spi_lookup(struct net *net, const xfrm_address_t *saddr)
{
	struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net);
	struct xfrm6_tunnel_spi *x6spi;

	hlist_for_each_entry_rcu(x6spi,
			     &xfrm6_tn->spi_byaddr[xfrm6_tunnel_spi_hash_byaddr(saddr)],
			     list_byaddr, lockdep_is_held(&xfrm6_tunnel_spi_lock)) {
		if (xfrm6_addr_equal(&x6spi->addr, saddr))
			return x6spi;
	}

	return NULL;
}

__be32 xfrm6_tunnel_spi_lookup(struct net *net, const xfrm_address_t *saddr)
{
	struct xfrm6_tunnel_spi *x6spi;
	u32 spi;

	rcu_read_lock_bh();
	x6spi = __xfrm6_tunnel_spi_lookup(net, saddr);
	spi = x6spi ? x6spi->spi : 0;
	rcu_read_unlock_bh();
	return htonl(spi);
}
EXPORT_SYMBOL(xfrm6_tunnel_spi_lookup);

static int __xfrm6_tunnel_spi_check(struct net *net, u32 spi)
{
	struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net);
	struct xfrm6_tunnel_spi *x6spi;
	int index = xfrm6_tunnel_spi_hash_byspi(spi);

	hlist_for_each_entry(x6spi,
			     &xfrm6_tn->spi_byspi[index],
			     list_byspi) {
		if (x6spi->spi == spi)
			return -1;
	}
	return index;
}

static u32 __xfrm6_tunnel_alloc_spi(struct net *net, xfrm_address_t *saddr)
{
	struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net);
	u32 spi;
	struct xfrm6_tunnel_spi *x6spi;
	int index;

	if (xfrm6_tn->spi < XFRM6_TUNNEL_SPI_MIN ||
	    xfrm6_tn->spi >= XFRM6_TUNNEL_SPI_MAX)
		xfrm6_tn->spi = XFRM6_TUNNEL_SPI_MIN;
	else
		xfrm6_tn->spi++;

	for (spi = xfrm6_tn->spi; spi <= XFRM6_TUNNEL_SPI_MAX; spi++) {
		index = __xfrm6_tunnel_spi_check(net, spi);
		if (index >= 0)
			goto alloc_spi;

		if (spi == XFRM6_TUNNEL_SPI_MAX)
			break;
	}
	for (spi = XFRM6_TUNNEL_SPI_MIN; spi < xfrm6_tn->spi; spi++) {
		index = __xfrm6_tunnel_spi_check(net, spi);
		if (index >= 0)
			goto alloc_spi;
	}
	spi = 0;
	goto out;
alloc_spi:
	xfrm6_tn->spi = spi;
	x6spi = kmem_cache_alloc(xfrm6_tunnel_spi_kmem, GFP_ATOMIC);
	if (!x6spi)
		goto out;

	memcpy(&x6spi->addr, saddr, sizeof(x6spi->addr));
	x6spi->spi = spi;
	refcount_set(&x6spi->refcnt, 1);

	hlist_add_head_rcu(&x6spi->list_byspi, &xfrm6_tn->spi_byspi[index]);

	index = xfrm6_tunnel_spi_hash_byaddr(saddr);
	hlist_add_head_rcu(&x6spi->list_byaddr, &xfrm6_tn->spi_byaddr[index]);
out:
	return spi;
}

__be32 xfrm6_tunnel_alloc_spi(struct net *net, xfrm_address_t *saddr)
{
	struct xfrm6_tunnel_spi *x6spi;
	u32 spi;

	spin_lock_bh(&xfrm6_tunnel_spi_lock);
	x6spi = __xfrm6_tunnel_spi_lookup(net, saddr);
	if (x6spi) {
		refcount_inc(&x6spi->refcnt);
		spi = x6spi->spi;
	} else
		spi = __xfrm6_tunnel_alloc_spi(net, saddr);
	spin_unlock_bh(&xfrm6_tunnel_spi_lock);

	return htonl(spi);
}
EXPORT_SYMBOL(xfrm6_tunnel_alloc_spi);

static void x6spi_destroy_rcu(struct rcu_head *head)
{
	kmem_cache_free(xfrm6_tunnel_spi_kmem,
			container_of(head, struct xfrm6_tunnel_spi, rcu_head));
}

static void xfrm6_tunnel_free_spi(struct net *net, xfrm_address_t *saddr)
{
	struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net);
	struct xfrm6_tunnel_spi *x6spi;
	struct hlist_node *n;

	spin_lock_bh(&xfrm6_tunnel_spi_lock);

	hlist_for_each_entry_safe(x6spi, n,
				  &xfrm6_tn->spi_byaddr[xfrm6_tunnel_spi_hash_byaddr(saddr)],
				  list_byaddr)
	{
		if (xfrm6_addr_equal(&x6spi->addr, saddr)) {
			if (refcount_dec_and_test(&x6spi->refcnt)) {
				hlist_del_rcu(&x6spi->list_byaddr);
				hlist_del_rcu(&x6spi->list_byspi);
				call_rcu(&x6spi->rcu_head, x6spi_destroy_rcu);
				break;
			}
		}
	}
	spin_unlock_bh(&xfrm6_tunnel_spi_lock);
}

static int xfrm6_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
{
	skb_push(skb, -skb_network_offset(skb));
	return 0;
}

static int xfrm6_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
{
	return skb_network_header(skb)[IP6CB(skb)->nhoff];
}

static int xfrm6_tunnel_rcv(struct sk_buff *skb)
{
	struct net *net = dev_net(skb->dev);
	const struct ipv6hdr *iph = ipv6_hdr(skb);
	__be32 spi;

	spi = xfrm6_tunnel_spi_lookup(net, (const xfrm_address_t *)&iph->saddr);
	return xfrm6_rcv_spi(skb, IPPROTO_IPV6, spi, NULL);
}

static int xfrm6_tunnel_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
			    u8 type, u8 code, int offset, __be32 info)
{
	/* xfrm6_tunnel native err handling */
	switch (type) {
	case ICMPV6_DEST_UNREACH:
		switch (code) {
		case ICMPV6_NOROUTE:
		case ICMPV6_ADM_PROHIBITED:
		case ICMPV6_NOT_NEIGHBOUR:
		case ICMPV6_ADDR_UNREACH:
		case ICMPV6_PORT_UNREACH:
		default:
			break;
		}
		break;
	case ICMPV6_PKT_TOOBIG:
		break;
	case ICMPV6_TIME_EXCEED:
		switch (code) {
		case ICMPV6_EXC_HOPLIMIT:
			break;
		case ICMPV6_EXC_FRAGTIME:
		default:
			break;
		}
		break;
	case ICMPV6_PARAMPROB:
		switch (code) {
		case ICMPV6_HDR_FIELD: break;
		case ICMPV6_UNK_NEXTHDR: break;
		case ICMPV6_UNK_OPTION: break;
		}
		break;
	default:
		break;
	}

	return 0;
}

static int xfrm6_tunnel_init_state(struct xfrm_state *x, struct netlink_ext_ack *extack)
{
	if (x->props.mode != XFRM_MODE_TUNNEL) {
		NL_SET_ERR_MSG(extack, "IPv6 tunnel can only be used with tunnel mode");
		return -EINVAL;
	}

	if (x->encap) {
		NL_SET_ERR_MSG(extack, "IPv6 tunnel is not compatible with encapsulation");
		return -EINVAL;
	}

	x->props.header_len = sizeof(struct ipv6hdr);

	return 0;
}

static void xfrm6_tunnel_destroy(struct xfrm_state *x)
{
	struct net *net = xs_net(x);

	xfrm6_tunnel_free_spi(net, (xfrm_address_t *)&x->props.saddr);
}

static const struct xfrm_type xfrm6_tunnel_type = {
	.owner          = THIS_MODULE,
	.proto		= IPPROTO_IPV6,
	.init_state	= xfrm6_tunnel_init_state,
	.destructor	= xfrm6_tunnel_destroy,
	.input		= xfrm6_tunnel_input,
	.output		= xfrm6_tunnel_output,
};

static struct xfrm6_tunnel xfrm6_tunnel_handler __read_mostly = {
	.handler	= xfrm6_tunnel_rcv,
	.err_handler	= xfrm6_tunnel_err,
	.priority	= 3,
};

static struct xfrm6_tunnel xfrm46_tunnel_handler __read_mostly = {
	.handler	= xfrm6_tunnel_rcv,
	.err_handler	= xfrm6_tunnel_err,
	.priority	= 3,
};

static int __net_init xfrm6_tunnel_net_init(struct net *net)
{
	struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net);
	unsigned int i;

	for (i = 0; i < XFRM6_TUNNEL_SPI_BYADDR_HSIZE; i++)
		INIT_HLIST_HEAD(&xfrm6_tn->spi_byaddr[i]);
	for (i = 0; i < XFRM6_TUNNEL_SPI_BYSPI_HSIZE; i++)
		INIT_HLIST_HEAD(&xfrm6_tn->spi_byspi[i]);
	xfrm6_tn->spi = 0;

	return 0;
}

static void __net_exit xfrm6_tunnel_net_exit(struct net *net)
{
	struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net);
	unsigned int i;

	xfrm_flush_gc();
	xfrm_state_flush(net, 0, false, true);

	for (i = 0; i < XFRM6_TUNNEL_SPI_BYADDR_HSIZE; i++)
		WARN_ON_ONCE(!hlist_empty(&xfrm6_tn->spi_byaddr[i]));

	for (i = 0; i < XFRM6_TUNNEL_SPI_BYSPI_HSIZE; i++)
		WARN_ON_ONCE(!hlist_empty(&xfrm6_tn->spi_byspi[i]));
}

static struct pernet_operations xfrm6_tunnel_net_ops = {
	.init	= xfrm6_tunnel_net_init,
	.exit	= xfrm6_tunnel_net_exit,
	.id	= &xfrm6_tunnel_net_id,
	.size	= sizeof(struct xfrm6_tunnel_net),
};

static int __init xfrm6_tunnel_init(void)
{
	int rv;

	xfrm6_tunnel_spi_kmem = KMEM_CACHE(xfrm6_tunnel_spi, SLAB_HWCACHE_ALIGN);
	if (!xfrm6_tunnel_spi_kmem)
		return -ENOMEM;
	rv = register_pernet_subsys(&xfrm6_tunnel_net_ops);
	if (rv < 0)
		goto out_pernet;
	rv = xfrm_register_type(&xfrm6_tunnel_type, AF_INET6);
	if (rv < 0)
		goto out_type;
	rv = xfrm6_tunnel_register(&xfrm6_tunnel_handler, AF_INET6);
	if (rv < 0)
		goto out_xfrm6;
	rv = xfrm6_tunnel_register(&xfrm46_tunnel_handler, AF_INET);
	if (rv < 0)
		goto out_xfrm46;
	return 0;

out_xfrm46:
	xfrm6_tunnel_deregister(&xfrm6_tunnel_handler, AF_INET6);
out_xfrm6:
	xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6);
out_type:
	unregister_pernet_subsys(&xfrm6_tunnel_net_ops);
out_pernet:
	kmem_cache_destroy(xfrm6_tunnel_spi_kmem);
	return rv;
}

static void __exit xfrm6_tunnel_fini(void)
{
	xfrm6_tunnel_deregister(&xfrm46_tunnel_handler, AF_INET);
	xfrm6_tunnel_deregister(&xfrm6_tunnel_handler, AF_INET6);
	xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6);
	unregister_pernet_subsys(&xfrm6_tunnel_net_ops);
	/* Someone maybe has gotten the xfrm6_tunnel_spi.
	 * So need to wait it.
	 */
	rcu_barrier();
	kmem_cache_destroy(xfrm6_tunnel_spi_kmem);
}

module_init(xfrm6_tunnel_init);
module_exit(xfrm6_tunnel_fini);
MODULE_DESCRIPTION("IPv6 XFRM tunnel driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_IPV6);