Remove obsolete #include <linux/config.h>
[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/list.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
34 #ifdef CONFIG_IPV6_XFRM6_TUNNEL_DEBUG
35 # define X6TDEBUG       3
36 #else
37 # define X6TDEBUG       1
38 #endif
39
40 #define X6TPRINTK(fmt, args...)         printk(fmt, ## args)
41 #define X6TNOPRINTK(fmt, args...)       do { ; } while(0)
42
43 #if X6TDEBUG >= 1
44 # define X6TPRINTK1     X6TPRINTK
45 #else
46 # define X6TPRINTK1     X6TNOPRINTK
47 #endif
48
49 #if X6TDEBUG >= 3
50 # define X6TPRINTK3     X6TPRINTK
51 #else
52 # define X6TPRINTK3     X6TNOPRINTK
53 #endif
54
55 /*
56  * xfrm_tunnel_spi things are for allocating unique id ("spi") 
57  * per xfrm_address_t.
58  */
59 struct xfrm6_tunnel_spi {
60         struct hlist_node list_byaddr;
61         struct hlist_node list_byspi;
62         xfrm_address_t addr;
63         u32 spi;
64         atomic_t refcnt;
65 #ifdef XFRM6_TUNNEL_SPI_MAGIC
66         u32 magic;
67 #endif
68 };
69
70 #ifdef CONFIG_IPV6_XFRM6_TUNNEL_DEBUG
71 # define XFRM6_TUNNEL_SPI_MAGIC 0xdeadbeef
72 #endif
73
74 static DEFINE_RWLOCK(xfrm6_tunnel_spi_lock);
75
76 static u32 xfrm6_tunnel_spi;
77
78 #define XFRM6_TUNNEL_SPI_MIN    1
79 #define XFRM6_TUNNEL_SPI_MAX    0xffffffff
80
81 static kmem_cache_t *xfrm6_tunnel_spi_kmem __read_mostly;
82
83 #define XFRM6_TUNNEL_SPI_BYADDR_HSIZE 256
84 #define XFRM6_TUNNEL_SPI_BYSPI_HSIZE 256
85
86 static struct hlist_head xfrm6_tunnel_spi_byaddr[XFRM6_TUNNEL_SPI_BYADDR_HSIZE];
87 static struct hlist_head xfrm6_tunnel_spi_byspi[XFRM6_TUNNEL_SPI_BYSPI_HSIZE];
88
89 #ifdef XFRM6_TUNNEL_SPI_MAGIC
90 static int x6spi_check_magic(const struct xfrm6_tunnel_spi *x6spi,
91                              const char *name)
92 {
93         if (unlikely(x6spi->magic != XFRM6_TUNNEL_SPI_MAGIC)) {
94                 X6TPRINTK3(KERN_DEBUG "%s(): x6spi object "
95                                       "at %p has corrupted magic %08x "
96                                       "(should be %08x)\n",
97                            name, x6spi, x6spi->magic, XFRM6_TUNNEL_SPI_MAGIC);
98                 return -1;
99         }
100         return 0;
101 }
102 #else
103 static int inline x6spi_check_magic(const struct xfrm6_tunnel_spi *x6spi,
104                                     const char *name)
105 {
106         return 0;
107 }
108 #endif
109
110 #define X6SPI_CHECK_MAGIC(x6spi) x6spi_check_magic((x6spi), __FUNCTION__)
111
112
113 static unsigned inline xfrm6_tunnel_spi_hash_byaddr(xfrm_address_t *addr)
114 {
115         unsigned h;
116
117         X6TPRINTK3(KERN_DEBUG "%s(addr=%p)\n", __FUNCTION__, addr);
118
119         h = addr->a6[0] ^ addr->a6[1] ^ addr->a6[2] ^ addr->a6[3];
120         h ^= h >> 16;
121         h ^= h >> 8;
122         h &= XFRM6_TUNNEL_SPI_BYADDR_HSIZE - 1;
123
124         X6TPRINTK3(KERN_DEBUG "%s() = %u\n", __FUNCTION__, h);
125
126         return h;
127 }
128
129 static unsigned inline xfrm6_tunnel_spi_hash_byspi(u32 spi)
130 {
131         return spi % XFRM6_TUNNEL_SPI_BYSPI_HSIZE;
132 }
133
134
135 static int xfrm6_tunnel_spi_init(void)
136 {
137         int i;
138
139         X6TPRINTK3(KERN_DEBUG "%s()\n", __FUNCTION__);
140
141         xfrm6_tunnel_spi = 0;
142         xfrm6_tunnel_spi_kmem = kmem_cache_create("xfrm6_tunnel_spi",
143                                                   sizeof(struct xfrm6_tunnel_spi),
144                                                   0, SLAB_HWCACHE_ALIGN,
145                                                   NULL, NULL);
146         if (!xfrm6_tunnel_spi_kmem) {
147                 X6TPRINTK1(KERN_ERR
148                            "%s(): failed to allocate xfrm6_tunnel_spi_kmem\n",
149                            __FUNCTION__);
150                 return -ENOMEM;
151         }
152
153         for (i = 0; i < XFRM6_TUNNEL_SPI_BYADDR_HSIZE; i++)
154                 INIT_HLIST_HEAD(&xfrm6_tunnel_spi_byaddr[i]);
155         for (i = 0; i < XFRM6_TUNNEL_SPI_BYSPI_HSIZE; i++)
156                 INIT_HLIST_HEAD(&xfrm6_tunnel_spi_byspi[i]);
157         return 0;
158 }
159
160 static void xfrm6_tunnel_spi_fini(void)
161 {
162         int i;
163
164         X6TPRINTK3(KERN_DEBUG "%s()\n", __FUNCTION__);
165
166         for (i = 0; i < XFRM6_TUNNEL_SPI_BYADDR_HSIZE; i++) {
167                 if (!hlist_empty(&xfrm6_tunnel_spi_byaddr[i]))
168                         goto err;
169         }
170         for (i = 0; i < XFRM6_TUNNEL_SPI_BYSPI_HSIZE; i++) {
171                 if (!hlist_empty(&xfrm6_tunnel_spi_byspi[i]))
172                         goto err;
173         }
174         kmem_cache_destroy(xfrm6_tunnel_spi_kmem);
175         xfrm6_tunnel_spi_kmem = NULL;
176         return;
177 err:
178         X6TPRINTK1(KERN_ERR "%s(): table is not empty\n", __FUNCTION__);
179         return;
180 }
181
182 static struct xfrm6_tunnel_spi *__xfrm6_tunnel_spi_lookup(xfrm_address_t *saddr)
183 {
184         struct xfrm6_tunnel_spi *x6spi;
185         struct hlist_node *pos;
186
187         X6TPRINTK3(KERN_DEBUG "%s(saddr=%p)\n", __FUNCTION__, saddr);
188
189         hlist_for_each_entry(x6spi, pos,
190                              &xfrm6_tunnel_spi_byaddr[xfrm6_tunnel_spi_hash_byaddr(saddr)],
191                              list_byaddr) {
192                 if (memcmp(&x6spi->addr, saddr, sizeof(x6spi->addr)) == 0) {
193                         X6SPI_CHECK_MAGIC(x6spi);
194                         X6TPRINTK3(KERN_DEBUG "%s() = %p(%u)\n", __FUNCTION__, x6spi, x6spi->spi);
195                         return x6spi;
196                 }
197         }
198
199         X6TPRINTK3(KERN_DEBUG "%s() = NULL(0)\n", __FUNCTION__);
200         return NULL;
201 }
202
203 u32 xfrm6_tunnel_spi_lookup(xfrm_address_t *saddr)
204 {
205         struct xfrm6_tunnel_spi *x6spi;
206         u32 spi;
207
208         X6TPRINTK3(KERN_DEBUG "%s(saddr=%p)\n", __FUNCTION__, saddr);
209
210         read_lock_bh(&xfrm6_tunnel_spi_lock);
211         x6spi = __xfrm6_tunnel_spi_lookup(saddr);
212         spi = x6spi ? x6spi->spi : 0;
213         read_unlock_bh(&xfrm6_tunnel_spi_lock);
214         return spi;
215 }
216
217 EXPORT_SYMBOL(xfrm6_tunnel_spi_lookup);
218
219 static u32 __xfrm6_tunnel_alloc_spi(xfrm_address_t *saddr)
220 {
221         u32 spi;
222         struct xfrm6_tunnel_spi *x6spi;
223         struct hlist_node *pos;
224         unsigned index;
225
226         X6TPRINTK3(KERN_DEBUG "%s(saddr=%p)\n", __FUNCTION__, saddr);
227
228         if (xfrm6_tunnel_spi < XFRM6_TUNNEL_SPI_MIN ||
229             xfrm6_tunnel_spi >= XFRM6_TUNNEL_SPI_MAX)
230                 xfrm6_tunnel_spi = XFRM6_TUNNEL_SPI_MIN;
231         else
232                 xfrm6_tunnel_spi++;
233
234         for (spi = xfrm6_tunnel_spi; spi <= XFRM6_TUNNEL_SPI_MAX; spi++) {
235                 index = xfrm6_tunnel_spi_hash_byspi(spi);
236                 hlist_for_each_entry(x6spi, pos, 
237                                      &xfrm6_tunnel_spi_byspi[index], 
238                                      list_byspi) {
239                         if (x6spi->spi == spi)
240                                 goto try_next_1;
241                 }
242                 xfrm6_tunnel_spi = spi;
243                 goto alloc_spi;
244 try_next_1:;
245         }
246         for (spi = XFRM6_TUNNEL_SPI_MIN; spi < xfrm6_tunnel_spi; spi++) {
247                 index = xfrm6_tunnel_spi_hash_byspi(spi);
248                 hlist_for_each_entry(x6spi, pos, 
249                                      &xfrm6_tunnel_spi_byspi[index], 
250                                      list_byspi) {
251                         if (x6spi->spi == spi)
252                                 goto try_next_2;
253                 }
254                 xfrm6_tunnel_spi = spi;
255                 goto alloc_spi;
256 try_next_2:;
257         }
258         spi = 0;
259         goto out;
260 alloc_spi:
261         X6TPRINTK3(KERN_DEBUG "%s(): allocate new spi for " NIP6_FMT "\n",
262                               __FUNCTION__, 
263                               NIP6(*(struct in6_addr *)saddr));
264         x6spi = kmem_cache_alloc(xfrm6_tunnel_spi_kmem, SLAB_ATOMIC);
265         if (!x6spi) {
266                 X6TPRINTK1(KERN_ERR "%s(): kmem_cache_alloc() failed\n", 
267                            __FUNCTION__);
268                 goto out;
269         }
270 #ifdef XFRM6_TUNNEL_SPI_MAGIC
271         x6spi->magic = XFRM6_TUNNEL_SPI_MAGIC;
272 #endif
273         memcpy(&x6spi->addr, saddr, sizeof(x6spi->addr));
274         x6spi->spi = spi;
275         atomic_set(&x6spi->refcnt, 1);
276
277         hlist_add_head(&x6spi->list_byspi, &xfrm6_tunnel_spi_byspi[index]);
278
279         index = xfrm6_tunnel_spi_hash_byaddr(saddr);
280         hlist_add_head(&x6spi->list_byaddr, &xfrm6_tunnel_spi_byaddr[index]);
281         X6SPI_CHECK_MAGIC(x6spi);
282 out:
283         X6TPRINTK3(KERN_DEBUG "%s() = %u\n", __FUNCTION__, spi);
284         return spi;
285 }
286
287 u32 xfrm6_tunnel_alloc_spi(xfrm_address_t *saddr)
288 {
289         struct xfrm6_tunnel_spi *x6spi;
290         u32 spi;
291
292         X6TPRINTK3(KERN_DEBUG "%s(saddr=%p)\n", __FUNCTION__, saddr);
293
294         write_lock_bh(&xfrm6_tunnel_spi_lock);
295         x6spi = __xfrm6_tunnel_spi_lookup(saddr);
296         if (x6spi) {
297                 atomic_inc(&x6spi->refcnt);
298                 spi = x6spi->spi;
299         } else
300                 spi = __xfrm6_tunnel_alloc_spi(saddr);
301         write_unlock_bh(&xfrm6_tunnel_spi_lock);
302
303         X6TPRINTK3(KERN_DEBUG "%s() = %u\n", __FUNCTION__, spi);
304
305         return spi;
306 }
307
308 EXPORT_SYMBOL(xfrm6_tunnel_alloc_spi);
309
310 void xfrm6_tunnel_free_spi(xfrm_address_t *saddr)
311 {
312         struct xfrm6_tunnel_spi *x6spi;
313         struct hlist_node *pos, *n;
314
315         X6TPRINTK3(KERN_DEBUG "%s(saddr=%p)\n", __FUNCTION__, saddr);
316
317         write_lock_bh(&xfrm6_tunnel_spi_lock);
318
319         hlist_for_each_entry_safe(x6spi, pos, n, 
320                                   &xfrm6_tunnel_spi_byaddr[xfrm6_tunnel_spi_hash_byaddr(saddr)],
321                                   list_byaddr)
322         {
323                 if (memcmp(&x6spi->addr, saddr, sizeof(x6spi->addr)) == 0) {
324                         X6TPRINTK3(KERN_DEBUG "%s(): x6spi object for " NIP6_FMT 
325                                               " found at %p\n",
326                                    __FUNCTION__, 
327                                    NIP6(*(struct in6_addr *)saddr),
328                                    x6spi);
329                         X6SPI_CHECK_MAGIC(x6spi);
330                         if (atomic_dec_and_test(&x6spi->refcnt)) {
331                                 hlist_del(&x6spi->list_byaddr);
332                                 hlist_del(&x6spi->list_byspi);
333                                 kmem_cache_free(xfrm6_tunnel_spi_kmem, x6spi);
334                                 break;
335                         }
336                 }
337         }
338         write_unlock_bh(&xfrm6_tunnel_spi_lock);
339 }
340
341 EXPORT_SYMBOL(xfrm6_tunnel_free_spi);
342
343 static int xfrm6_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
344 {
345         struct ipv6hdr *top_iph;
346
347         top_iph = (struct ipv6hdr *)skb->data;
348         top_iph->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
349
350         return 0;
351 }
352
353 static int xfrm6_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
354 {
355         return 0;
356 }
357
358 static int xfrm6_tunnel_rcv(struct sk_buff *skb)
359 {
360         struct ipv6hdr *iph = skb->nh.ipv6h;
361         u32 spi;
362
363         spi = xfrm6_tunnel_spi_lookup((xfrm_address_t *)&iph->saddr);
364         return xfrm6_rcv_spi(skb, spi);
365 }
366
367 static int xfrm6_tunnel_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
368                             int type, int code, int offset, __u32 info)
369 {
370         /* xfrm6_tunnel native err handling */
371         switch (type) {
372         case ICMPV6_DEST_UNREACH: 
373                 switch (code) {
374                 case ICMPV6_NOROUTE: 
375                 case ICMPV6_ADM_PROHIBITED:
376                 case ICMPV6_NOT_NEIGHBOUR:
377                 case ICMPV6_ADDR_UNREACH:
378                 case ICMPV6_PORT_UNREACH:
379                 default:
380                         X6TPRINTK3(KERN_DEBUG
381                                    "xfrm6_tunnel: Destination Unreach.\n");
382                         break;
383                 }
384                 break;
385         case ICMPV6_PKT_TOOBIG:
386                         X6TPRINTK3(KERN_DEBUG 
387                                    "xfrm6_tunnel: Packet Too Big.\n");
388                 break;
389         case ICMPV6_TIME_EXCEED:
390                 switch (code) {
391                 case ICMPV6_EXC_HOPLIMIT:
392                         X6TPRINTK3(KERN_DEBUG
393                                    "xfrm6_tunnel: Too small Hoplimit.\n");
394                         break;
395                 case ICMPV6_EXC_FRAGTIME:
396                 default: 
397                         break;
398                 }
399                 break;
400         case ICMPV6_PARAMPROB:
401                 switch (code) {
402                 case ICMPV6_HDR_FIELD: break;
403                 case ICMPV6_UNK_NEXTHDR: break;
404                 case ICMPV6_UNK_OPTION: break;
405                 }
406                 break;
407         default:
408                 break;
409         }
410
411         return 0;
412 }
413
414 static int xfrm6_tunnel_init_state(struct xfrm_state *x)
415 {
416         if (!x->props.mode)
417                 return -EINVAL;
418
419         if (x->encap)
420                 return -EINVAL;
421
422         x->props.header_len = sizeof(struct ipv6hdr);
423
424         return 0;
425 }
426
427 static void xfrm6_tunnel_destroy(struct xfrm_state *x)
428 {
429         xfrm6_tunnel_free_spi((xfrm_address_t *)&x->props.saddr);
430 }
431
432 static struct xfrm_type xfrm6_tunnel_type = {
433         .description    = "IP6IP6",
434         .owner          = THIS_MODULE,
435         .proto          = IPPROTO_IPV6,
436         .init_state     = xfrm6_tunnel_init_state,
437         .destructor     = xfrm6_tunnel_destroy,
438         .input          = xfrm6_tunnel_input,
439         .output         = xfrm6_tunnel_output,
440 };
441
442 static struct xfrm6_tunnel xfrm6_tunnel_handler = {
443         .handler        = xfrm6_tunnel_rcv,
444         .err_handler    = xfrm6_tunnel_err,
445         .priority       = 2,
446 };
447
448 static int __init xfrm6_tunnel_init(void)
449 {
450         X6TPRINTK3(KERN_DEBUG "%s()\n", __FUNCTION__);
451
452         if (xfrm_register_type(&xfrm6_tunnel_type, AF_INET6) < 0) {
453                 X6TPRINTK1(KERN_ERR
454                            "xfrm6_tunnel init: can't add xfrm type\n");
455                 return -EAGAIN;
456         }
457         if (xfrm6_tunnel_register(&xfrm6_tunnel_handler)) {
458                 X6TPRINTK1(KERN_ERR
459                            "xfrm6_tunnel init(): can't add handler\n");
460                 xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6);
461                 return -EAGAIN;
462         }
463         if (xfrm6_tunnel_spi_init() < 0) {
464                 X6TPRINTK1(KERN_ERR
465                            "xfrm6_tunnel init: failed to initialize spi\n");
466                 xfrm6_tunnel_deregister(&xfrm6_tunnel_handler);
467                 xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6);
468                 return -EAGAIN;
469         }
470         return 0;
471 }
472
473 static void __exit xfrm6_tunnel_fini(void)
474 {
475         X6TPRINTK3(KERN_DEBUG "%s()\n", __FUNCTION__);
476
477         xfrm6_tunnel_spi_fini();
478         if (xfrm6_tunnel_deregister(&xfrm6_tunnel_handler))
479                 X6TPRINTK1(KERN_ERR 
480                            "xfrm6_tunnel close: can't remove handler\n");
481         if (xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6) < 0)
482                 X6TPRINTK1(KERN_ERR
483                            "xfrm6_tunnel close: can't remove xfrm type\n");
484 }
485
486 module_init(xfrm6_tunnel_init);
487 module_exit(xfrm6_tunnel_fini);
488 MODULE_LICENSE("GPL");