net: Allow modules to use is_skb_forwardable
[linux-2.6-block.git] / net / ipv6 / xfrm6_tunnel.c
CommitLineData
1da177e4
LT
1/*
2 * Copyright (C)2003,2004 USAGI/WIDE Project
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
1ab1457c 8 *
1da177e4
LT
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
1ab1457c 13 *
1da177e4 14 * You should have received a copy of the GNU General Public License
a99421d9 15 * along with this program; if not, see <http://www.gnu.org/licenses/>.
1da177e4
LT
16 *
17 * Authors Mitsuru KANDA <mk@linux-ipv6.org>
18 * YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
19 *
20 * Based on net/ipv4/xfrm4_tunnel.c
21 *
22 */
1da177e4
LT
23#include <linux/module.h>
24#include <linux/xfrm.h>
5a0e3ad6 25#include <linux/slab.h>
91cc3bb0 26#include <linux/rculist.h>
1da177e4
LT
27#include <net/ip.h>
28#include <net/xfrm.h>
29#include <net/ipv6.h>
1da177e4
LT
30#include <linux/ipv6.h>
31#include <linux/icmpv6.h>
4a3e2f71 32#include <linux/mutex.h>
a1664773
AD
33#include <net/netns/generic.h>
34
35#define XFRM6_TUNNEL_SPI_BYADDR_HSIZE 256
36#define XFRM6_TUNNEL_SPI_BYSPI_HSIZE 256
37
38#define XFRM6_TUNNEL_SPI_MIN 1
39#define XFRM6_TUNNEL_SPI_MAX 0xffffffff
40
41struct xfrm6_tunnel_net {
42 struct hlist_head spi_byaddr[XFRM6_TUNNEL_SPI_BYADDR_HSIZE];
43 struct hlist_head spi_byspi[XFRM6_TUNNEL_SPI_BYSPI_HSIZE];
44 u32 spi;
45};
46
47static int xfrm6_tunnel_net_id __read_mostly;
48static inline struct xfrm6_tunnel_net *xfrm6_tunnel_pernet(struct net *net)
49{
50 return net_generic(net, xfrm6_tunnel_net_id);
51}
1da177e4 52
1da177e4 53/*
1ab1457c 54 * xfrm_tunnel_spi things are for allocating unique id ("spi")
1da177e4
LT
55 * per xfrm_address_t.
56 */
57struct xfrm6_tunnel_spi {
91cc3bb0
ED
58 struct hlist_node list_byaddr;
59 struct hlist_node list_byspi;
60 xfrm_address_t addr;
61 u32 spi;
62 atomic_t refcnt;
63 struct rcu_head rcu_head;
1da177e4
LT
64};
65
91cc3bb0 66static DEFINE_SPINLOCK(xfrm6_tunnel_spi_lock);
1da177e4 67
e18b890b 68static struct kmem_cache *xfrm6_tunnel_spi_kmem __read_mostly;
1da177e4 69
95c96174 70static inline unsigned int xfrm6_tunnel_spi_hash_byaddr(const xfrm_address_t *addr)
1da177e4 71{
95c96174 72 unsigned int h;
1da177e4 73
2b464f61 74 h = ipv6_addr_hash((const struct in6_addr *)addr);
1da177e4
LT
75 h ^= h >> 16;
76 h ^= h >> 8;
77 h &= XFRM6_TUNNEL_SPI_BYADDR_HSIZE - 1;
78
1da177e4
LT
79 return h;
80}
81
95c96174 82static inline unsigned int xfrm6_tunnel_spi_hash_byspi(u32 spi)
1da177e4
LT
83{
84 return spi % XFRM6_TUNNEL_SPI_BYSPI_HSIZE;
85}
86
b71d1d42 87static struct xfrm6_tunnel_spi *__xfrm6_tunnel_spi_lookup(struct net *net, const xfrm_address_t *saddr)
1da177e4 88{
a1664773 89 struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net);
1da177e4 90 struct xfrm6_tunnel_spi *x6spi;
1da177e4 91
b67bfe0d 92 hlist_for_each_entry_rcu(x6spi,
a1664773 93 &xfrm6_tn->spi_byaddr[xfrm6_tunnel_spi_hash_byaddr(saddr)],
1da177e4 94 list_byaddr) {
ff88b30c 95 if (xfrm6_addr_equal(&x6spi->addr, saddr))
1da177e4 96 return x6spi;
1da177e4
LT
97 }
98
1da177e4
LT
99 return NULL;
100}
101
b71d1d42 102__be32 xfrm6_tunnel_spi_lookup(struct net *net, const xfrm_address_t *saddr)
1da177e4
LT
103{
104 struct xfrm6_tunnel_spi *x6spi;
105 u32 spi;
106
91cc3bb0 107 rcu_read_lock_bh();
a1664773 108 x6spi = __xfrm6_tunnel_spi_lookup(net, saddr);
1da177e4 109 spi = x6spi ? x6spi->spi : 0;
91cc3bb0 110 rcu_read_unlock_bh();
5b122545 111 return htonl(spi);
1da177e4
LT
112}
113
114EXPORT_SYMBOL(xfrm6_tunnel_spi_lookup);
115
a1664773 116static int __xfrm6_tunnel_spi_check(struct net *net, u32 spi)
df8ea19b 117{
a1664773 118 struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net);
df8ea19b
YH
119 struct xfrm6_tunnel_spi *x6spi;
120 int index = xfrm6_tunnel_spi_hash_byspi(spi);
df8ea19b 121
b67bfe0d 122 hlist_for_each_entry(x6spi,
a1664773 123 &xfrm6_tn->spi_byspi[index],
df8ea19b
YH
124 list_byspi) {
125 if (x6spi->spi == spi)
126 return -1;
127 }
128 return index;
129}
130
a1664773 131static u32 __xfrm6_tunnel_alloc_spi(struct net *net, xfrm_address_t *saddr)
1da177e4 132{
a1664773 133 struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net);
1da177e4
LT
134 u32 spi;
135 struct xfrm6_tunnel_spi *x6spi;
df8ea19b 136 int index;
1da177e4 137
a1664773
AD
138 if (xfrm6_tn->spi < XFRM6_TUNNEL_SPI_MIN ||
139 xfrm6_tn->spi >= XFRM6_TUNNEL_SPI_MAX)
140 xfrm6_tn->spi = XFRM6_TUNNEL_SPI_MIN;
1da177e4 141 else
a1664773 142 xfrm6_tn->spi++;
1da177e4 143
a1664773
AD
144 for (spi = xfrm6_tn->spi; spi <= XFRM6_TUNNEL_SPI_MAX; spi++) {
145 index = __xfrm6_tunnel_spi_check(net, spi);
df8ea19b
YH
146 if (index >= 0)
147 goto alloc_spi;
1da177e4 148 }
a1664773
AD
149 for (spi = XFRM6_TUNNEL_SPI_MIN; spi < xfrm6_tn->spi; spi++) {
150 index = __xfrm6_tunnel_spi_check(net, spi);
df8ea19b
YH
151 if (index >= 0)
152 goto alloc_spi;
1da177e4
LT
153 }
154 spi = 0;
155 goto out;
156alloc_spi:
a1664773 157 xfrm6_tn->spi = spi;
54e6ecb2 158 x6spi = kmem_cache_alloc(xfrm6_tunnel_spi_kmem, GFP_ATOMIC);
a922ba55 159 if (!x6spi)
1da177e4 160 goto out;
a922ba55 161
1da177e4
LT
162 memcpy(&x6spi->addr, saddr, sizeof(x6spi->addr));
163 x6spi->spi = spi;
164 atomic_set(&x6spi->refcnt, 1);
165
a1664773 166 hlist_add_head_rcu(&x6spi->list_byspi, &xfrm6_tn->spi_byspi[index]);
1da177e4
LT
167
168 index = xfrm6_tunnel_spi_hash_byaddr(saddr);
a1664773 169 hlist_add_head_rcu(&x6spi->list_byaddr, &xfrm6_tn->spi_byaddr[index]);
1da177e4 170out:
1da177e4
LT
171 return spi;
172}
173
a1664773 174__be32 xfrm6_tunnel_alloc_spi(struct net *net, xfrm_address_t *saddr)
1da177e4
LT
175{
176 struct xfrm6_tunnel_spi *x6spi;
177 u32 spi;
178
91cc3bb0 179 spin_lock_bh(&xfrm6_tunnel_spi_lock);
a1664773 180 x6spi = __xfrm6_tunnel_spi_lookup(net, saddr);
1da177e4
LT
181 if (x6spi) {
182 atomic_inc(&x6spi->refcnt);
183 spi = x6spi->spi;
184 } else
a1664773 185 spi = __xfrm6_tunnel_alloc_spi(net, saddr);
91cc3bb0 186 spin_unlock_bh(&xfrm6_tunnel_spi_lock);
1da177e4 187
5b122545 188 return htonl(spi);
1da177e4
LT
189}
190
191EXPORT_SYMBOL(xfrm6_tunnel_alloc_spi);
192
91cc3bb0
ED
193static void x6spi_destroy_rcu(struct rcu_head *head)
194{
195 kmem_cache_free(xfrm6_tunnel_spi_kmem,
196 container_of(head, struct xfrm6_tunnel_spi, rcu_head));
197}
198
6f747aca 199static void xfrm6_tunnel_free_spi(struct net *net, xfrm_address_t *saddr)
1da177e4 200{
a1664773 201 struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net);
1da177e4 202 struct xfrm6_tunnel_spi *x6spi;
b67bfe0d 203 struct hlist_node *n;
1da177e4 204
91cc3bb0 205 spin_lock_bh(&xfrm6_tunnel_spi_lock);
1da177e4 206
b67bfe0d 207 hlist_for_each_entry_safe(x6spi, n,
a1664773 208 &xfrm6_tn->spi_byaddr[xfrm6_tunnel_spi_hash_byaddr(saddr)],
1da177e4
LT
209 list_byaddr)
210 {
ff88b30c 211 if (xfrm6_addr_equal(&x6spi->addr, saddr)) {
1da177e4 212 if (atomic_dec_and_test(&x6spi->refcnt)) {
91cc3bb0
ED
213 hlist_del_rcu(&x6spi->list_byaddr);
214 hlist_del_rcu(&x6spi->list_byspi);
215 call_rcu(&x6spi->rcu_head, x6spi_destroy_rcu);
1da177e4
LT
216 break;
217 }
218 }
219 }
91cc3bb0 220 spin_unlock_bh(&xfrm6_tunnel_spi_lock);
1da177e4
LT
221}
222
1da177e4
LT
223static int xfrm6_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
224{
7b277b1a 225 skb_push(skb, -skb_network_offset(skb));
1da177e4
LT
226 return 0;
227}
228
e695633e 229static int xfrm6_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
1da177e4 230{
04663d0b 231 return skb_network_header(skb)[IP6CB(skb)->nhoff];
1da177e4
LT
232}
233
d2acc347 234static int xfrm6_tunnel_rcv(struct sk_buff *skb)
1da177e4 235{
a1664773 236 struct net *net = dev_net(skb->dev);
b71d1d42 237 const struct ipv6hdr *iph = ipv6_hdr(skb);
a252cc23 238 __be32 spi;
1da177e4 239
b71d1d42 240 spi = xfrm6_tunnel_spi_lookup(net, (const xfrm_address_t *)&iph->saddr);
6ac3f664 241 return xfrm6_rcv_spi(skb, IPPROTO_IPV6, spi);
1da177e4
LT
242}
243
d2acc347 244static int xfrm6_tunnel_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
d5fdd6ba 245 u8 type, u8 code, int offset, __be32 info)
1da177e4 246{
1da177e4
LT
247 /* xfrm6_tunnel native err handling */
248 switch (type) {
1ab1457c 249 case ICMPV6_DEST_UNREACH:
1da177e4 250 switch (code) {
1ab1457c 251 case ICMPV6_NOROUTE:
1da177e4
LT
252 case ICMPV6_ADM_PROHIBITED:
253 case ICMPV6_NOT_NEIGHBOUR:
254 case ICMPV6_ADDR_UNREACH:
255 case ICMPV6_PORT_UNREACH:
256 default:
1da177e4
LT
257 break;
258 }
259 break;
260 case ICMPV6_PKT_TOOBIG:
1da177e4
LT
261 break;
262 case ICMPV6_TIME_EXCEED:
263 switch (code) {
264 case ICMPV6_EXC_HOPLIMIT:
1da177e4
LT
265 break;
266 case ICMPV6_EXC_FRAGTIME:
1ab1457c 267 default:
1da177e4
LT
268 break;
269 }
270 break;
271 case ICMPV6_PARAMPROB:
272 switch (code) {
273 case ICMPV6_HDR_FIELD: break;
274 case ICMPV6_UNK_NEXTHDR: break;
275 case ICMPV6_UNK_OPTION: break;
276 }
277 break;
278 default:
279 break;
280 }
d2acc347
HX
281
282 return 0;
1da177e4
LT
283}
284
72cb6962 285static int xfrm6_tunnel_init_state(struct xfrm_state *x)
1da177e4 286{
7e49e6de 287 if (x->props.mode != XFRM_MODE_TUNNEL)
1da177e4
LT
288 return -EINVAL;
289
290 if (x->encap)
291 return -EINVAL;
292
293 x->props.header_len = sizeof(struct ipv6hdr);
294
295 return 0;
296}
297
298static void xfrm6_tunnel_destroy(struct xfrm_state *x)
299{
a1664773
AD
300 struct net *net = xs_net(x);
301
302 xfrm6_tunnel_free_spi(net, (xfrm_address_t *)&x->props.saddr);
1da177e4
LT
303}
304
533cb5b0 305static const struct xfrm_type xfrm6_tunnel_type = {
1da177e4
LT
306 .description = "IP6IP6",
307 .owner = THIS_MODULE,
308 .proto = IPPROTO_IPV6,
309 .init_state = xfrm6_tunnel_init_state,
310 .destructor = xfrm6_tunnel_destroy,
311 .input = xfrm6_tunnel_input,
312 .output = xfrm6_tunnel_output,
313};
314
3ff2cfa5 315static struct xfrm6_tunnel xfrm6_tunnel_handler __read_mostly = {
1da177e4 316 .handler = xfrm6_tunnel_rcv,
d2acc347
HX
317 .err_handler = xfrm6_tunnel_err,
318 .priority = 2,
1da177e4
LT
319};
320
3ff2cfa5 321static struct xfrm6_tunnel xfrm46_tunnel_handler __read_mostly = {
73d605d1
KM
322 .handler = xfrm6_tunnel_rcv,
323 .err_handler = xfrm6_tunnel_err,
324 .priority = 2,
325};
326
a1664773
AD
327static int __net_init xfrm6_tunnel_net_init(struct net *net)
328{
329 struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net);
330 unsigned int i;
331
332 for (i = 0; i < XFRM6_TUNNEL_SPI_BYADDR_HSIZE; i++)
333 INIT_HLIST_HEAD(&xfrm6_tn->spi_byaddr[i]);
334 for (i = 0; i < XFRM6_TUNNEL_SPI_BYSPI_HSIZE; i++)
335 INIT_HLIST_HEAD(&xfrm6_tn->spi_byspi[i]);
336 xfrm6_tn->spi = 0;
337
338 return 0;
339}
340
341static void __net_exit xfrm6_tunnel_net_exit(struct net *net)
342{
343}
344
345static struct pernet_operations xfrm6_tunnel_net_ops = {
346 .init = xfrm6_tunnel_net_init,
347 .exit = xfrm6_tunnel_net_exit,
348 .id = &xfrm6_tunnel_net_id,
349 .size = sizeof(struct xfrm6_tunnel_net),
350};
351
1da177e4
LT
352static int __init xfrm6_tunnel_init(void)
353{
e924960d
AD
354 int rv;
355
d5aa407f
AD
356 xfrm6_tunnel_spi_kmem = kmem_cache_create("xfrm6_tunnel_spi",
357 sizeof(struct xfrm6_tunnel_spi),
358 0, SLAB_HWCACHE_ALIGN,
359 NULL);
360 if (!xfrm6_tunnel_spi_kmem)
361 return -ENOMEM;
362 rv = register_pernet_subsys(&xfrm6_tunnel_net_ops);
363 if (rv < 0)
364 goto out_pernet;
e924960d
AD
365 rv = xfrm_register_type(&xfrm6_tunnel_type, AF_INET6);
366 if (rv < 0)
d5aa407f 367 goto out_type;
e924960d
AD
368 rv = xfrm6_tunnel_register(&xfrm6_tunnel_handler, AF_INET6);
369 if (rv < 0)
d5aa407f 370 goto out_xfrm6;
e924960d
AD
371 rv = xfrm6_tunnel_register(&xfrm46_tunnel_handler, AF_INET);
372 if (rv < 0)
d5aa407f 373 goto out_xfrm46;
1da177e4 374 return 0;
5ce1bbb9 375
d5aa407f 376out_xfrm46:
5ce1bbb9 377 xfrm6_tunnel_deregister(&xfrm6_tunnel_handler, AF_INET6);
d5aa407f 378out_xfrm6:
5ce1bbb9 379 xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6);
d5aa407f
AD
380out_type:
381 unregister_pernet_subsys(&xfrm6_tunnel_net_ops);
382out_pernet:
383 kmem_cache_destroy(xfrm6_tunnel_spi_kmem);
e924960d 384 return rv;
1da177e4
LT
385}
386
387static void __exit xfrm6_tunnel_fini(void)
388{
73d605d1
KM
389 xfrm6_tunnel_deregister(&xfrm46_tunnel_handler, AF_INET);
390 xfrm6_tunnel_deregister(&xfrm6_tunnel_handler, AF_INET6);
a922ba55 391 xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6);
d5aa407f
AD
392 unregister_pernet_subsys(&xfrm6_tunnel_net_ops);
393 kmem_cache_destroy(xfrm6_tunnel_spi_kmem);
1da177e4
LT
394}
395
396module_init(xfrm6_tunnel_init);
397module_exit(xfrm6_tunnel_fini);
398MODULE_LICENSE("GPL");
d3d6dd3a 399MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_IPV6);