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24#include <linux/module.h>
25#include <linux/xfrm.h>
26#include <linux/slab.h>
27#include <linux/rculist.h>
28#include <net/ip.h>
29#include <net/xfrm.h>
30#include <net/ipv6.h>
31#include <linux/ipv6.h>
32#include <linux/icmpv6.h>
33#include <linux/mutex.h>
34#include <net/netns/generic.h>
35
36#define XFRM6_TUNNEL_SPI_BYADDR_HSIZE 256
37#define XFRM6_TUNNEL_SPI_BYSPI_HSIZE 256
38
39#define XFRM6_TUNNEL_SPI_MIN 1
40#define XFRM6_TUNNEL_SPI_MAX 0xffffffff
41
42struct xfrm6_tunnel_net {
43 struct hlist_head spi_byaddr[XFRM6_TUNNEL_SPI_BYADDR_HSIZE];
44 struct hlist_head spi_byspi[XFRM6_TUNNEL_SPI_BYSPI_HSIZE];
45 u32 spi;
46};
47
48static int xfrm6_tunnel_net_id __read_mostly;
49static inline struct xfrm6_tunnel_net *xfrm6_tunnel_pernet(struct net *net)
50{
51 return net_generic(net, xfrm6_tunnel_net_id);
52}
53
54
55
56
57
58struct xfrm6_tunnel_spi {
59 struct hlist_node list_byaddr;
60 struct hlist_node list_byspi;
61 xfrm_address_t addr;
62 u32 spi;
63 atomic_t refcnt;
64 struct rcu_head rcu_head;
65};
66
67static DEFINE_SPINLOCK(xfrm6_tunnel_spi_lock);
68
69static struct kmem_cache *xfrm6_tunnel_spi_kmem __read_mostly;
70
71static inline unsigned xfrm6_tunnel_spi_hash_byaddr(xfrm_address_t *addr)
72{
73 unsigned h;
74
75 h = (__force u32)(addr->a6[0] ^ addr->a6[1] ^ addr->a6[2] ^ addr->a6[3]);
76 h ^= h >> 16;
77 h ^= h >> 8;
78 h &= XFRM6_TUNNEL_SPI_BYADDR_HSIZE - 1;
79
80 return h;
81}
82
83static inline unsigned xfrm6_tunnel_spi_hash_byspi(u32 spi)
84{
85 return spi % XFRM6_TUNNEL_SPI_BYSPI_HSIZE;
86}
87
88static struct xfrm6_tunnel_spi *__xfrm6_tunnel_spi_lookup(struct net *net, xfrm_address_t *saddr)
89{
90 struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net);
91 struct xfrm6_tunnel_spi *x6spi;
92 struct hlist_node *pos;
93
94 hlist_for_each_entry_rcu(x6spi, pos,
95 &xfrm6_tn->spi_byaddr[xfrm6_tunnel_spi_hash_byaddr(saddr)],
96 list_byaddr) {
97 if (memcmp(&x6spi->addr, saddr, sizeof(x6spi->addr)) == 0)
98 return x6spi;
99 }
100
101 return NULL;
102}
103
104__be32 xfrm6_tunnel_spi_lookup(struct net *net, xfrm_address_t *saddr)
105{
106 struct xfrm6_tunnel_spi *x6spi;
107 u32 spi;
108
109 rcu_read_lock_bh();
110 x6spi = __xfrm6_tunnel_spi_lookup(net, saddr);
111 spi = x6spi ? x6spi->spi : 0;
112 rcu_read_unlock_bh();
113 return htonl(spi);
114}
115
116EXPORT_SYMBOL(xfrm6_tunnel_spi_lookup);
117
118static int __xfrm6_tunnel_spi_check(struct net *net, u32 spi)
119{
120 struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net);
121 struct xfrm6_tunnel_spi *x6spi;
122 int index = xfrm6_tunnel_spi_hash_byspi(spi);
123 struct hlist_node *pos;
124
125 hlist_for_each_entry(x6spi, pos,
126 &xfrm6_tn->spi_byspi[index],
127 list_byspi) {
128 if (x6spi->spi == spi)
129 return -1;
130 }
131 return index;
132}
133
134static u32 __xfrm6_tunnel_alloc_spi(struct net *net, xfrm_address_t *saddr)
135{
136 struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net);
137 u32 spi;
138 struct xfrm6_tunnel_spi *x6spi;
139 int index;
140
141 if (xfrm6_tn->spi < XFRM6_TUNNEL_SPI_MIN ||
142 xfrm6_tn->spi >= XFRM6_TUNNEL_SPI_MAX)
143 xfrm6_tn->spi = XFRM6_TUNNEL_SPI_MIN;
144 else
145 xfrm6_tn->spi++;
146
147 for (spi = xfrm6_tn->spi; spi <= XFRM6_TUNNEL_SPI_MAX; spi++) {
148 index = __xfrm6_tunnel_spi_check(net, spi);
149 if (index >= 0)
150 goto alloc_spi;
151 }
152 for (spi = XFRM6_TUNNEL_SPI_MIN; spi < xfrm6_tn->spi; spi++) {
153 index = __xfrm6_tunnel_spi_check(net, spi);
154 if (index >= 0)
155 goto alloc_spi;
156 }
157 spi = 0;
158 goto out;
159alloc_spi:
160 xfrm6_tn->spi = spi;
161 x6spi = kmem_cache_alloc(xfrm6_tunnel_spi_kmem, GFP_ATOMIC);
162 if (!x6spi)
163 goto out;
164
165 memcpy(&x6spi->addr, saddr, sizeof(x6spi->addr));
166 x6spi->spi = spi;
167 atomic_set(&x6spi->refcnt, 1);
168
169 hlist_add_head_rcu(&x6spi->list_byspi, &xfrm6_tn->spi_byspi[index]);
170
171 index = xfrm6_tunnel_spi_hash_byaddr(saddr);
172 hlist_add_head_rcu(&x6spi->list_byaddr, &xfrm6_tn->spi_byaddr[index]);
173out:
174 return spi;
175}
176
177__be32 xfrm6_tunnel_alloc_spi(struct net *net, xfrm_address_t *saddr)
178{
179 struct xfrm6_tunnel_spi *x6spi;
180 u32 spi;
181
182 spin_lock_bh(&xfrm6_tunnel_spi_lock);
183 x6spi = __xfrm6_tunnel_spi_lookup(net, saddr);
184 if (x6spi) {
185 atomic_inc(&x6spi->refcnt);
186 spi = x6spi->spi;
187 } else
188 spi = __xfrm6_tunnel_alloc_spi(net, saddr);
189 spin_unlock_bh(&xfrm6_tunnel_spi_lock);
190
191 return htonl(spi);
192}
193
194EXPORT_SYMBOL(xfrm6_tunnel_alloc_spi);
195
196static void x6spi_destroy_rcu(struct rcu_head *head)
197{
198 kmem_cache_free(xfrm6_tunnel_spi_kmem,
199 container_of(head, struct xfrm6_tunnel_spi, rcu_head));
200}
201
202static void xfrm6_tunnel_free_spi(struct net *net, xfrm_address_t *saddr)
203{
204 struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net);
205 struct xfrm6_tunnel_spi *x6spi;
206 struct hlist_node *pos, *n;
207
208 spin_lock_bh(&xfrm6_tunnel_spi_lock);
209
210 hlist_for_each_entry_safe(x6spi, pos, n,
211 &xfrm6_tn->spi_byaddr[xfrm6_tunnel_spi_hash_byaddr(saddr)],
212 list_byaddr)
213 {
214 if (memcmp(&x6spi->addr, saddr, sizeof(x6spi->addr)) == 0) {
215 if (atomic_dec_and_test(&x6spi->refcnt)) {
216 hlist_del_rcu(&x6spi->list_byaddr);
217 hlist_del_rcu(&x6spi->list_byspi);
218 call_rcu(&x6spi->rcu_head, x6spi_destroy_rcu);
219 break;
220 }
221 }
222 }
223 spin_unlock_bh(&xfrm6_tunnel_spi_lock);
224}
225
226static int xfrm6_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
227{
228 skb_push(skb, -skb_network_offset(skb));
229 return 0;
230}
231
232static int xfrm6_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
233{
234 return skb_network_header(skb)[IP6CB(skb)->nhoff];
235}
236
237static int xfrm6_tunnel_rcv(struct sk_buff *skb)
238{
239 struct net *net = dev_net(skb->dev);
240 struct ipv6hdr *iph = ipv6_hdr(skb);
241 __be32 spi;
242
243 spi = xfrm6_tunnel_spi_lookup(net, (xfrm_address_t *)&iph->saddr);
244 return xfrm6_rcv_spi(skb, IPPROTO_IPV6, spi) > 0 ? : 0;
245}
246
247static int xfrm6_tunnel_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
248 u8 type, u8 code, int offset, __be32 info)
249{
250
251 switch (type) {
252 case ICMPV6_DEST_UNREACH:
253 switch (code) {
254 case ICMPV6_NOROUTE:
255 case ICMPV6_ADM_PROHIBITED:
256 case ICMPV6_NOT_NEIGHBOUR:
257 case ICMPV6_ADDR_UNREACH:
258 case ICMPV6_PORT_UNREACH:
259 default:
260 break;
261 }
262 break;
263 case ICMPV6_PKT_TOOBIG:
264 break;
265 case ICMPV6_TIME_EXCEED:
266 switch (code) {
267 case ICMPV6_EXC_HOPLIMIT:
268 break;
269 case ICMPV6_EXC_FRAGTIME:
270 default:
271 break;
272 }
273 break;
274 case ICMPV6_PARAMPROB:
275 switch (code) {
276 case ICMPV6_HDR_FIELD: break;
277 case ICMPV6_UNK_NEXTHDR: break;
278 case ICMPV6_UNK_OPTION: break;
279 }
280 break;
281 default:
282 break;
283 }
284
285 return 0;
286}
287
288static int xfrm6_tunnel_init_state(struct xfrm_state *x)
289{
290 if (x->props.mode != XFRM_MODE_TUNNEL)
291 return -EINVAL;
292
293 if (x->encap)
294 return -EINVAL;
295
296 x->props.header_len = sizeof(struct ipv6hdr);
297
298 return 0;
299}
300
301static void xfrm6_tunnel_destroy(struct xfrm_state *x)
302{
303 struct net *net = xs_net(x);
304
305 xfrm6_tunnel_free_spi(net, (xfrm_address_t *)&x->props.saddr);
306}
307
308static const struct xfrm_type xfrm6_tunnel_type = {
309 .description = "IP6IP6",
310 .owner = THIS_MODULE,
311 .proto = IPPROTO_IPV6,
312 .init_state = xfrm6_tunnel_init_state,
313 .destructor = xfrm6_tunnel_destroy,
314 .input = xfrm6_tunnel_input,
315 .output = xfrm6_tunnel_output,
316};
317
318static struct xfrm6_tunnel xfrm6_tunnel_handler __read_mostly = {
319 .handler = xfrm6_tunnel_rcv,
320 .err_handler = xfrm6_tunnel_err,
321 .priority = 2,
322};
323
324static struct xfrm6_tunnel xfrm46_tunnel_handler __read_mostly = {
325 .handler = xfrm6_tunnel_rcv,
326 .err_handler = xfrm6_tunnel_err,
327 .priority = 2,
328};
329
330static int __net_init xfrm6_tunnel_net_init(struct net *net)
331{
332 struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net);
333 unsigned int i;
334
335 for (i = 0; i < XFRM6_TUNNEL_SPI_BYADDR_HSIZE; i++)
336 INIT_HLIST_HEAD(&xfrm6_tn->spi_byaddr[i]);
337 for (i = 0; i < XFRM6_TUNNEL_SPI_BYSPI_HSIZE; i++)
338 INIT_HLIST_HEAD(&xfrm6_tn->spi_byspi[i]);
339 xfrm6_tn->spi = 0;
340
341 return 0;
342}
343
344static void __net_exit xfrm6_tunnel_net_exit(struct net *net)
345{
346}
347
348static struct pernet_operations xfrm6_tunnel_net_ops = {
349 .init = xfrm6_tunnel_net_init,
350 .exit = xfrm6_tunnel_net_exit,
351 .id = &xfrm6_tunnel_net_id,
352 .size = sizeof(struct xfrm6_tunnel_net),
353};
354
355static int __init xfrm6_tunnel_init(void)
356{
357 int rv;
358
359 xfrm6_tunnel_spi_kmem = kmem_cache_create("xfrm6_tunnel_spi",
360 sizeof(struct xfrm6_tunnel_spi),
361 0, SLAB_HWCACHE_ALIGN,
362 NULL);
363 if (!xfrm6_tunnel_spi_kmem)
364 return -ENOMEM;
365 rv = register_pernet_subsys(&xfrm6_tunnel_net_ops);
366 if (rv < 0)
367 goto out_pernet;
368 rv = xfrm_register_type(&xfrm6_tunnel_type, AF_INET6);
369 if (rv < 0)
370 goto out_type;
371 rv = xfrm6_tunnel_register(&xfrm6_tunnel_handler, AF_INET6);
372 if (rv < 0)
373 goto out_xfrm6;
374 rv = xfrm6_tunnel_register(&xfrm46_tunnel_handler, AF_INET);
375 if (rv < 0)
376 goto out_xfrm46;
377 return 0;
378
379out_xfrm46:
380 xfrm6_tunnel_deregister(&xfrm6_tunnel_handler, AF_INET6);
381out_xfrm6:
382 xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6);
383out_type:
384 unregister_pernet_subsys(&xfrm6_tunnel_net_ops);
385out_pernet:
386 kmem_cache_destroy(xfrm6_tunnel_spi_kmem);
387 return rv;
388}
389
390static void __exit xfrm6_tunnel_fini(void)
391{
392 xfrm6_tunnel_deregister(&xfrm46_tunnel_handler, AF_INET);
393 xfrm6_tunnel_deregister(&xfrm6_tunnel_handler, AF_INET6);
394 xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6);
395 unregister_pernet_subsys(&xfrm6_tunnel_net_ops);
396 kmem_cache_destroy(xfrm6_tunnel_spi_kmem);
397}
398
399module_init(xfrm6_tunnel_init);
400module_exit(xfrm6_tunnel_fini);
401MODULE_LICENSE("GPL");
402MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_IPV6);
403
