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, see <http://www.gnu.org/licenses/>.
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 */
23 #include <linux/module.h>
24 #include <linux/xfrm.h>
25 #include <linux/slab.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;
xfrm6_tunnel_pernet(struct net * net)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
xfrm6_tunnel_spi_hash_byaddr(const xfrm_address_t * addr)70 static inline unsigned int xfrm6_tunnel_spi_hash_byaddr(const xfrm_address_t *addr)
71 {
72 unsigned int h;
73
74 h = ipv6_addr_hash((const struct in6_addr *)addr);
75 h ^= h >> 16;
76 h ^= h >> 8;
77 h &= XFRM6_TUNNEL_SPI_BYADDR_HSIZE - 1;
78
79 return h;
80 }
81
xfrm6_tunnel_spi_hash_byspi(u32 spi)82 static inline unsigned int xfrm6_tunnel_spi_hash_byspi(u32 spi)
83 {
84 return spi % XFRM6_TUNNEL_SPI_BYSPI_HSIZE;
85 }
86
__xfrm6_tunnel_spi_lookup(struct net * net,const xfrm_address_t * saddr)87 static struct xfrm6_tunnel_spi *__xfrm6_tunnel_spi_lookup(struct net *net, const xfrm_address_t *saddr)
88 {
89 struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net);
90 struct xfrm6_tunnel_spi *x6spi;
91
92 hlist_for_each_entry_rcu(x6spi,
93 &xfrm6_tn->spi_byaddr[xfrm6_tunnel_spi_hash_byaddr(saddr)],
94 list_byaddr) {
95 if (xfrm6_addr_equal(&x6spi->addr, saddr))
96 return x6spi;
97 }
98
99 return NULL;
100 }
101
xfrm6_tunnel_spi_lookup(struct net * net,const xfrm_address_t * saddr)102 __be32 xfrm6_tunnel_spi_lookup(struct net *net, const xfrm_address_t *saddr)
103 {
104 struct xfrm6_tunnel_spi *x6spi;
105 u32 spi;
106
107 rcu_read_lock_bh();
108 x6spi = __xfrm6_tunnel_spi_lookup(net, saddr);
109 spi = x6spi ? x6spi->spi : 0;
110 rcu_read_unlock_bh();
111 return htonl(spi);
112 }
113 EXPORT_SYMBOL(xfrm6_tunnel_spi_lookup);
114
__xfrm6_tunnel_spi_check(struct net * net,u32 spi)115 static int __xfrm6_tunnel_spi_check(struct net *net, u32 spi)
116 {
117 struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net);
118 struct xfrm6_tunnel_spi *x6spi;
119 int index = xfrm6_tunnel_spi_hash_byspi(spi);
120
121 hlist_for_each_entry(x6spi,
122 &xfrm6_tn->spi_byspi[index],
123 list_byspi) {
124 if (x6spi->spi == spi)
125 return -1;
126 }
127 return index;
128 }
129
__xfrm6_tunnel_alloc_spi(struct net * net,xfrm_address_t * saddr)130 static u32 __xfrm6_tunnel_alloc_spi(struct net *net, xfrm_address_t *saddr)
131 {
132 struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net);
133 u32 spi;
134 struct xfrm6_tunnel_spi *x6spi;
135 int index;
136
137 if (xfrm6_tn->spi < XFRM6_TUNNEL_SPI_MIN ||
138 xfrm6_tn->spi >= XFRM6_TUNNEL_SPI_MAX)
139 xfrm6_tn->spi = XFRM6_TUNNEL_SPI_MIN;
140 else
141 xfrm6_tn->spi++;
142
143 for (spi = xfrm6_tn->spi; spi <= XFRM6_TUNNEL_SPI_MAX; spi++) {
144 index = __xfrm6_tunnel_spi_check(net, spi);
145 if (index >= 0)
146 goto alloc_spi;
147 }
148 for (spi = XFRM6_TUNNEL_SPI_MIN; spi < xfrm6_tn->spi; spi++) {
149 index = __xfrm6_tunnel_spi_check(net, spi);
150 if (index >= 0)
151 goto alloc_spi;
152 }
153 spi = 0;
154 goto out;
155 alloc_spi:
156 xfrm6_tn->spi = spi;
157 x6spi = kmem_cache_alloc(xfrm6_tunnel_spi_kmem, GFP_ATOMIC);
158 if (!x6spi)
159 goto out;
160
161 memcpy(&x6spi->addr, saddr, sizeof(x6spi->addr));
162 x6spi->spi = spi;
163 atomic_set(&x6spi->refcnt, 1);
164
165 hlist_add_head_rcu(&x6spi->list_byspi, &xfrm6_tn->spi_byspi[index]);
166
167 index = xfrm6_tunnel_spi_hash_byaddr(saddr);
168 hlist_add_head_rcu(&x6spi->list_byaddr, &xfrm6_tn->spi_byaddr[index]);
169 out:
170 return spi;
171 }
172
xfrm6_tunnel_alloc_spi(struct net * net,xfrm_address_t * saddr)173 __be32 xfrm6_tunnel_alloc_spi(struct net *net, xfrm_address_t *saddr)
174 {
175 struct xfrm6_tunnel_spi *x6spi;
176 u32 spi;
177
178 spin_lock_bh(&xfrm6_tunnel_spi_lock);
179 x6spi = __xfrm6_tunnel_spi_lookup(net, saddr);
180 if (x6spi) {
181 atomic_inc(&x6spi->refcnt);
182 spi = x6spi->spi;
183 } else
184 spi = __xfrm6_tunnel_alloc_spi(net, saddr);
185 spin_unlock_bh(&xfrm6_tunnel_spi_lock);
186
187 return htonl(spi);
188 }
189 EXPORT_SYMBOL(xfrm6_tunnel_alloc_spi);
190
x6spi_destroy_rcu(struct rcu_head * head)191 static void x6spi_destroy_rcu(struct rcu_head *head)
192 {
193 kmem_cache_free(xfrm6_tunnel_spi_kmem,
194 container_of(head, struct xfrm6_tunnel_spi, rcu_head));
195 }
196
xfrm6_tunnel_free_spi(struct net * net,xfrm_address_t * saddr)197 static void xfrm6_tunnel_free_spi(struct net *net, xfrm_address_t *saddr)
198 {
199 struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net);
200 struct xfrm6_tunnel_spi *x6spi;
201 struct hlist_node *n;
202
203 spin_lock_bh(&xfrm6_tunnel_spi_lock);
204
205 hlist_for_each_entry_safe(x6spi, n,
206 &xfrm6_tn->spi_byaddr[xfrm6_tunnel_spi_hash_byaddr(saddr)],
207 list_byaddr)
208 {
209 if (xfrm6_addr_equal(&x6spi->addr, saddr)) {
210 if (atomic_dec_and_test(&x6spi->refcnt)) {
211 hlist_del_rcu(&x6spi->list_byaddr);
212 hlist_del_rcu(&x6spi->list_byspi);
213 call_rcu(&x6spi->rcu_head, x6spi_destroy_rcu);
214 break;
215 }
216 }
217 }
218 spin_unlock_bh(&xfrm6_tunnel_spi_lock);
219 }
220
xfrm6_tunnel_output(struct xfrm_state * x,struct sk_buff * skb)221 static int xfrm6_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
222 {
223 skb_push(skb, -skb_network_offset(skb));
224 return 0;
225 }
226
xfrm6_tunnel_input(struct xfrm_state * x,struct sk_buff * skb)227 static int xfrm6_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
228 {
229 return skb_network_header(skb)[IP6CB(skb)->nhoff];
230 }
231
xfrm6_tunnel_rcv(struct sk_buff * skb)232 static int xfrm6_tunnel_rcv(struct sk_buff *skb)
233 {
234 struct net *net = dev_net(skb->dev);
235 const struct ipv6hdr *iph = ipv6_hdr(skb);
236 __be32 spi;
237
238 spi = xfrm6_tunnel_spi_lookup(net, (const xfrm_address_t *)&iph->saddr);
239 return xfrm6_rcv_spi(skb, IPPROTO_IPV6, spi);
240 }
241
xfrm6_tunnel_err(struct sk_buff * skb,struct inet6_skb_parm * opt,u8 type,u8 code,int offset,__be32 info)242 static int xfrm6_tunnel_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
243 u8 type, u8 code, int offset, __be32 info)
244 {
245 /* xfrm6_tunnel native err handling */
246 switch (type) {
247 case ICMPV6_DEST_UNREACH:
248 switch (code) {
249 case ICMPV6_NOROUTE:
250 case ICMPV6_ADM_PROHIBITED:
251 case ICMPV6_NOT_NEIGHBOUR:
252 case ICMPV6_ADDR_UNREACH:
253 case ICMPV6_PORT_UNREACH:
254 default:
255 break;
256 }
257 break;
258 case ICMPV6_PKT_TOOBIG:
259 break;
260 case ICMPV6_TIME_EXCEED:
261 switch (code) {
262 case ICMPV6_EXC_HOPLIMIT:
263 break;
264 case ICMPV6_EXC_FRAGTIME:
265 default:
266 break;
267 }
268 break;
269 case ICMPV6_PARAMPROB:
270 switch (code) {
271 case ICMPV6_HDR_FIELD: break;
272 case ICMPV6_UNK_NEXTHDR: break;
273 case ICMPV6_UNK_OPTION: break;
274 }
275 break;
276 default:
277 break;
278 }
279
280 return 0;
281 }
282
xfrm6_tunnel_init_state(struct xfrm_state * x)283 static int xfrm6_tunnel_init_state(struct xfrm_state *x)
284 {
285 if (x->props.mode != XFRM_MODE_TUNNEL)
286 return -EINVAL;
287
288 if (x->encap)
289 return -EINVAL;
290
291 x->props.header_len = sizeof(struct ipv6hdr);
292
293 return 0;
294 }
295
xfrm6_tunnel_destroy(struct xfrm_state * x)296 static void xfrm6_tunnel_destroy(struct xfrm_state *x)
297 {
298 struct net *net = xs_net(x);
299
300 xfrm6_tunnel_free_spi(net, (xfrm_address_t *)&x->props.saddr);
301 }
302
303 static const struct xfrm_type xfrm6_tunnel_type = {
304 .description = "IP6IP6",
305 .owner = THIS_MODULE,
306 .proto = IPPROTO_IPV6,
307 .init_state = xfrm6_tunnel_init_state,
308 .destructor = xfrm6_tunnel_destroy,
309 .input = xfrm6_tunnel_input,
310 .output = xfrm6_tunnel_output,
311 };
312
313 static struct xfrm6_tunnel xfrm6_tunnel_handler __read_mostly = {
314 .handler = xfrm6_tunnel_rcv,
315 .err_handler = xfrm6_tunnel_err,
316 .priority = 2,
317 };
318
319 static struct xfrm6_tunnel xfrm46_tunnel_handler __read_mostly = {
320 .handler = xfrm6_tunnel_rcv,
321 .err_handler = xfrm6_tunnel_err,
322 .priority = 2,
323 };
324
xfrm6_tunnel_net_init(struct net * net)325 static int __net_init xfrm6_tunnel_net_init(struct net *net)
326 {
327 struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net);
328 unsigned int i;
329
330 for (i = 0; i < XFRM6_TUNNEL_SPI_BYADDR_HSIZE; i++)
331 INIT_HLIST_HEAD(&xfrm6_tn->spi_byaddr[i]);
332 for (i = 0; i < XFRM6_TUNNEL_SPI_BYSPI_HSIZE; i++)
333 INIT_HLIST_HEAD(&xfrm6_tn->spi_byspi[i]);
334 xfrm6_tn->spi = 0;
335
336 return 0;
337 }
338
xfrm6_tunnel_net_exit(struct net * net)339 static void __net_exit xfrm6_tunnel_net_exit(struct net *net)
340 {
341 }
342
343 static struct pernet_operations xfrm6_tunnel_net_ops = {
344 .init = xfrm6_tunnel_net_init,
345 .exit = xfrm6_tunnel_net_exit,
346 .id = &xfrm6_tunnel_net_id,
347 .size = sizeof(struct xfrm6_tunnel_net),
348 };
349
xfrm6_tunnel_init(void)350 static int __init xfrm6_tunnel_init(void)
351 {
352 int rv;
353
354 xfrm6_tunnel_spi_kmem = kmem_cache_create("xfrm6_tunnel_spi",
355 sizeof(struct xfrm6_tunnel_spi),
356 0, SLAB_HWCACHE_ALIGN,
357 NULL);
358 if (!xfrm6_tunnel_spi_kmem)
359 return -ENOMEM;
360 rv = register_pernet_subsys(&xfrm6_tunnel_net_ops);
361 if (rv < 0)
362 goto out_pernet;
363 rv = xfrm_register_type(&xfrm6_tunnel_type, AF_INET6);
364 if (rv < 0)
365 goto out_type;
366 rv = xfrm6_tunnel_register(&xfrm6_tunnel_handler, AF_INET6);
367 if (rv < 0)
368 goto out_xfrm6;
369 rv = xfrm6_tunnel_register(&xfrm46_tunnel_handler, AF_INET);
370 if (rv < 0)
371 goto out_xfrm46;
372 return 0;
373
374 out_xfrm46:
375 xfrm6_tunnel_deregister(&xfrm6_tunnel_handler, AF_INET6);
376 out_xfrm6:
377 xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6);
378 out_type:
379 unregister_pernet_subsys(&xfrm6_tunnel_net_ops);
380 out_pernet:
381 kmem_cache_destroy(xfrm6_tunnel_spi_kmem);
382 return rv;
383 }
384
xfrm6_tunnel_fini(void)385 static void __exit xfrm6_tunnel_fini(void)
386 {
387 xfrm6_tunnel_deregister(&xfrm46_tunnel_handler, AF_INET);
388 xfrm6_tunnel_deregister(&xfrm6_tunnel_handler, AF_INET6);
389 xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6);
390 unregister_pernet_subsys(&xfrm6_tunnel_net_ops);
391 kmem_cache_destroy(xfrm6_tunnel_spi_kmem);
392 }
393
394 module_init(xfrm6_tunnel_init);
395 module_exit(xfrm6_tunnel_fini);
396 MODULE_LICENSE("GPL");
397 MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_IPV6);
398