net: remove INIT_RCU_HEAD() usage
[linux-2.6.git] / net / ipv6 / xfrm6_tunnel.c
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.
8  *
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.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software
16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
17  *
18  * Authors      Mitsuru KANDA  <mk@linux-ipv6.org>
19  *              YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
20  *
21  * Based on net/ipv4/xfrm4_tunnel.c
22  *
23  */
24 #include <linux/module.h>
25 #include <linux/xfrm.h>
26 #include <linux/rculist.h>
27 #include <net/ip.h>
28 #include <net/xfrm.h>
29 #include <net/ipv6.h>
30 #include <linux/ipv6.h>
31 #include <linux/icmpv6.h>
32 #include <linux/mutex.h>
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
41 struct 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
47 static int xfrm6_tunnel_net_id __read_mostly;
48 static inline struct xfrm6_tunnel_net *xfrm6_tunnel_pernet(struct net *net)
49 {
50         return net_generic(net, xfrm6_tunnel_net_id);
51 }
52
53 /*
54  * xfrm_tunnel_spi things are for allocating unique id ("spi")
55  * per xfrm_address_t.
56  */
57 struct xfrm6_tunnel_spi {
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;
64 };
65
66 static DEFINE_SPINLOCK(xfrm6_tunnel_spi_lock);
67
68 static struct kmem_cache *xfrm6_tunnel_spi_kmem __read_mostly;
69
70 static inline unsigned xfrm6_tunnel_spi_hash_byaddr(xfrm_address_t *addr)
71 {
72         unsigned h;
73
74         h = (__force u32)(addr->a6[0] ^ addr->a6[1] ^ addr->a6[2] ^ addr->a6[3]);
75         h ^= h >> 16;
76         h ^= h >> 8;
77         h &= XFRM6_TUNNEL_SPI_BYADDR_HSIZE - 1;
78
79         return h;
80 }
81
82 static inline unsigned xfrm6_tunnel_spi_hash_byspi(u32 spi)
83 {
84         return spi % XFRM6_TUNNEL_SPI_BYSPI_HSIZE;
85 }
86
87 static struct xfrm6_tunnel_spi *__xfrm6_tunnel_spi_lookup(struct net *net, xfrm_address_t *saddr)
88 {
89         struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net);
90         struct xfrm6_tunnel_spi *x6spi;
91         struct hlist_node *pos;
92
93         hlist_for_each_entry_rcu(x6spi, pos,
94                              &xfrm6_tn->spi_byaddr[xfrm6_tunnel_spi_hash_byaddr(saddr)],
95                              list_byaddr) {
96                 if (memcmp(&x6spi->addr, saddr, sizeof(x6spi->addr)) == 0)
97                         return x6spi;
98         }
99
100         return NULL;
101 }
102
103 __be32 xfrm6_tunnel_spi_lookup(struct net *net, xfrm_address_t *saddr)
104 {
105         struct xfrm6_tunnel_spi *x6spi;
106         u32 spi;
107
108         rcu_read_lock_bh();
109         x6spi = __xfrm6_tunnel_spi_lookup(net, saddr);
110         spi = x6spi ? x6spi->spi : 0;
111         rcu_read_unlock_bh();
112         return htonl(spi);
113 }
114
115 EXPORT_SYMBOL(xfrm6_tunnel_spi_lookup);
116
117 static int __xfrm6_tunnel_spi_check(struct net *net, u32 spi)
118 {
119         struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net);
120         struct xfrm6_tunnel_spi *x6spi;
121         int index = xfrm6_tunnel_spi_hash_byspi(spi);
122         struct hlist_node *pos;
123
124         hlist_for_each_entry(x6spi, pos,
125                              &xfrm6_tn->spi_byspi[index],
126                              list_byspi) {
127                 if (x6spi->spi == spi)
128                         return -1;
129         }
130         return index;
131 }
132
133 static u32 __xfrm6_tunnel_alloc_spi(struct net *net, xfrm_address_t *saddr)
134 {
135         struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net);
136         u32 spi;
137         struct xfrm6_tunnel_spi *x6spi;
138         int index;
139
140         if (xfrm6_tn->spi < XFRM6_TUNNEL_SPI_MIN ||
141             xfrm6_tn->spi >= XFRM6_TUNNEL_SPI_MAX)
142                 xfrm6_tn->spi = XFRM6_TUNNEL_SPI_MIN;
143         else
144                 xfrm6_tn->spi++;
145
146         for (spi = xfrm6_tn->spi; spi <= XFRM6_TUNNEL_SPI_MAX; spi++) {
147                 index = __xfrm6_tunnel_spi_check(net, spi);
148                 if (index >= 0)
149                         goto alloc_spi;
150         }
151         for (spi = XFRM6_TUNNEL_SPI_MIN; spi < xfrm6_tn->spi; spi++) {
152                 index = __xfrm6_tunnel_spi_check(net, spi);
153                 if (index >= 0)
154                         goto alloc_spi;
155         }
156         spi = 0;
157         goto out;
158 alloc_spi:
159         xfrm6_tn->spi = spi;
160         x6spi = kmem_cache_alloc(xfrm6_tunnel_spi_kmem, GFP_ATOMIC);
161         if (!x6spi)
162                 goto out;
163
164         memcpy(&x6spi->addr, saddr, sizeof(x6spi->addr));
165         x6spi->spi = spi;
166         atomic_set(&x6spi->refcnt, 1);
167
168         hlist_add_head_rcu(&x6spi->list_byspi, &xfrm6_tn->spi_byspi[index]);
169
170         index = xfrm6_tunnel_spi_hash_byaddr(saddr);
171         hlist_add_head_rcu(&x6spi->list_byaddr, &xfrm6_tn->spi_byaddr[index]);
172 out:
173         return spi;
174 }
175
176 __be32 xfrm6_tunnel_alloc_spi(struct net *net, xfrm_address_t *saddr)
177 {
178         struct xfrm6_tunnel_spi *x6spi;
179         u32 spi;
180
181         spin_lock_bh(&xfrm6_tunnel_spi_lock);
182         x6spi = __xfrm6_tunnel_spi_lookup(net, saddr);
183         if (x6spi) {
184                 atomic_inc(&x6spi->refcnt);
185                 spi = x6spi->spi;
186         } else
187                 spi = __xfrm6_tunnel_alloc_spi(net, saddr);
188         spin_unlock_bh(&xfrm6_tunnel_spi_lock);
189
190         return htonl(spi);
191 }
192
193 EXPORT_SYMBOL(xfrm6_tunnel_alloc_spi);
194
195 static void x6spi_destroy_rcu(struct rcu_head *head)
196 {
197         kmem_cache_free(xfrm6_tunnel_spi_kmem,
198                         container_of(head, struct xfrm6_tunnel_spi, rcu_head));
199 }
200
201 void xfrm6_tunnel_free_spi(struct net *net, xfrm_address_t *saddr)
202 {
203         struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net);
204         struct xfrm6_tunnel_spi *x6spi;
205         struct hlist_node *pos, *n;
206
207         spin_lock_bh(&xfrm6_tunnel_spi_lock);
208
209         hlist_for_each_entry_safe(x6spi, pos, n,
210                                   &xfrm6_tn->spi_byaddr[xfrm6_tunnel_spi_hash_byaddr(saddr)],
211                                   list_byaddr)
212         {
213                 if (memcmp(&x6spi->addr, saddr, sizeof(x6spi->addr)) == 0) {
214                         if (atomic_dec_and_test(&x6spi->refcnt)) {
215                                 hlist_del_rcu(&x6spi->list_byaddr);
216                                 hlist_del_rcu(&x6spi->list_byspi);
217                                 call_rcu(&x6spi->rcu_head, x6spi_destroy_rcu);
218                                 break;
219                         }
220                 }
221         }
222         spin_unlock_bh(&xfrm6_tunnel_spi_lock);
223 }
224
225 EXPORT_SYMBOL(xfrm6_tunnel_free_spi);
226
227 static int xfrm6_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
228 {
229         skb_push(skb, -skb_network_offset(skb));
230         return 0;
231 }
232
233 static int xfrm6_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
234 {
235         return skb_network_header(skb)[IP6CB(skb)->nhoff];
236 }
237
238 static int xfrm6_tunnel_rcv(struct sk_buff *skb)
239 {
240         struct net *net = dev_net(skb->dev);
241         struct ipv6hdr *iph = ipv6_hdr(skb);
242         __be32 spi;
243
244         spi = xfrm6_tunnel_spi_lookup(net, (xfrm_address_t *)&iph->saddr);
245         return xfrm6_rcv_spi(skb, IPPROTO_IPV6, spi) > 0 ? : 0;
246 }
247
248 static int xfrm6_tunnel_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
249                             u8 type, u8 code, int offset, __be32 info)
250 {
251         /* xfrm6_tunnel native err handling */
252         switch (type) {
253         case ICMPV6_DEST_UNREACH:
254                 switch (code) {
255                 case ICMPV6_NOROUTE:
256                 case ICMPV6_ADM_PROHIBITED:
257                 case ICMPV6_NOT_NEIGHBOUR:
258                 case ICMPV6_ADDR_UNREACH:
259                 case ICMPV6_PORT_UNREACH:
260                 default:
261                         break;
262                 }
263                 break;
264         case ICMPV6_PKT_TOOBIG:
265                 break;
266         case ICMPV6_TIME_EXCEED:
267                 switch (code) {
268                 case ICMPV6_EXC_HOPLIMIT:
269                         break;
270                 case ICMPV6_EXC_FRAGTIME:
271                 default:
272                         break;
273                 }
274                 break;
275         case ICMPV6_PARAMPROB:
276                 switch (code) {
277                 case ICMPV6_HDR_FIELD: break;
278                 case ICMPV6_UNK_NEXTHDR: break;
279                 case ICMPV6_UNK_OPTION: break;
280                 }
281                 break;
282         default:
283                 break;
284         }
285
286         return 0;
287 }
288
289 static int xfrm6_tunnel_init_state(struct xfrm_state *x)
290 {
291         if (x->props.mode != XFRM_MODE_TUNNEL)
292                 return -EINVAL;
293
294         if (x->encap)
295                 return -EINVAL;
296
297         x->props.header_len = sizeof(struct ipv6hdr);
298
299         return 0;
300 }
301
302 static void xfrm6_tunnel_destroy(struct xfrm_state *x)
303 {
304         struct net *net = xs_net(x);
305
306         xfrm6_tunnel_free_spi(net, (xfrm_address_t *)&x->props.saddr);
307 }
308
309 static const struct xfrm_type xfrm6_tunnel_type = {
310         .description    = "IP6IP6",
311         .owner          = THIS_MODULE,
312         .proto          = IPPROTO_IPV6,
313         .init_state     = xfrm6_tunnel_init_state,
314         .destructor     = xfrm6_tunnel_destroy,
315         .input          = xfrm6_tunnel_input,
316         .output         = xfrm6_tunnel_output,
317 };
318
319 static struct xfrm6_tunnel xfrm6_tunnel_handler = {
320         .handler        = xfrm6_tunnel_rcv,
321         .err_handler    = xfrm6_tunnel_err,
322         .priority       = 2,
323 };
324
325 static struct xfrm6_tunnel xfrm46_tunnel_handler = {
326         .handler        = xfrm6_tunnel_rcv,
327         .err_handler    = xfrm6_tunnel_err,
328         .priority       = 2,
329 };
330
331 static int __net_init xfrm6_tunnel_net_init(struct net *net)
332 {
333         struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net);
334         unsigned int i;
335
336         for (i = 0; i < XFRM6_TUNNEL_SPI_BYADDR_HSIZE; i++)
337                 INIT_HLIST_HEAD(&xfrm6_tn->spi_byaddr[i]);
338         for (i = 0; i < XFRM6_TUNNEL_SPI_BYSPI_HSIZE; i++)
339                 INIT_HLIST_HEAD(&xfrm6_tn->spi_byspi[i]);
340         xfrm6_tn->spi = 0;
341
342         return 0;
343 }
344
345 static void __net_exit xfrm6_tunnel_net_exit(struct net *net)
346 {
347 }
348
349 static struct pernet_operations xfrm6_tunnel_net_ops = {
350         .init   = xfrm6_tunnel_net_init,
351         .exit   = xfrm6_tunnel_net_exit,
352         .id     = &xfrm6_tunnel_net_id,
353         .size   = sizeof(struct xfrm6_tunnel_net),
354 };
355
356 static int __init xfrm6_tunnel_init(void)
357 {
358         int rv;
359
360         xfrm6_tunnel_spi_kmem = kmem_cache_create("xfrm6_tunnel_spi",
361                                                   sizeof(struct xfrm6_tunnel_spi),
362                                                   0, SLAB_HWCACHE_ALIGN,
363                                                   NULL);
364         if (!xfrm6_tunnel_spi_kmem)
365                 return -ENOMEM;
366         rv = register_pernet_subsys(&xfrm6_tunnel_net_ops);
367         if (rv < 0)
368                 goto out_pernet;
369         rv = xfrm_register_type(&xfrm6_tunnel_type, AF_INET6);
370         if (rv < 0)
371                 goto out_type;
372         rv = xfrm6_tunnel_register(&xfrm6_tunnel_handler, AF_INET6);
373         if (rv < 0)
374                 goto out_xfrm6;
375         rv = xfrm6_tunnel_register(&xfrm46_tunnel_handler, AF_INET);
376         if (rv < 0)
377                 goto out_xfrm46;
378         return 0;
379
380 out_xfrm46:
381         xfrm6_tunnel_deregister(&xfrm6_tunnel_handler, AF_INET6);
382 out_xfrm6:
383         xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6);
384 out_type:
385         unregister_pernet_subsys(&xfrm6_tunnel_net_ops);
386 out_pernet:
387         kmem_cache_destroy(xfrm6_tunnel_spi_kmem);
388         return rv;
389 }
390
391 static void __exit xfrm6_tunnel_fini(void)
392 {
393         xfrm6_tunnel_deregister(&xfrm46_tunnel_handler, AF_INET);
394         xfrm6_tunnel_deregister(&xfrm6_tunnel_handler, AF_INET6);
395         xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6);
396         unregister_pernet_subsys(&xfrm6_tunnel_net_ops);
397         kmem_cache_destroy(xfrm6_tunnel_spi_kmem);
398 }
399
400 module_init(xfrm6_tunnel_init);
401 module_exit(xfrm6_tunnel_fini);
402 MODULE_LICENSE("GPL");
403 MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_IPV6);